106 results on '"Peter B. Best"'
Search Results
2. Demographic parameters of southern right whales off South Africa
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Doug S Butterworth, Peter B. Best, and Anabela Brandão
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Estimation ,education.field_of_study ,biology ,media_common.quotation_subject ,Population ,Ice calving ,Aquatic Science ,biology.organism_classification ,Confidence interval ,Geography ,Statistics ,Population growth ,Animal Science and Zoology ,Reproduction ,education ,Right whale ,Survival rate ,Ecology, Evolution, Behavior and Systematics ,media_common ,Demography - Abstract
Aerial counts of right whale cow-calf pairs on the south coast of South Africa between 1971 and 1998 indicate an annual instantaneouspopulation increase rate of 0.068 per year (SE = 0.004) over this period. Annual photographic surveys since 1979 have resulted in 901resightings of 550 individual cows. Observed calving intervals ranged from 2-15 years, with a principal mode at 3 years and secondarymodes at 6, 9 and 12 years, but these make no allowance for missed calvings. Using the model of Payne et al. (1990), a maximum calvinginterval of 5 years produces the best fit to the data giving a mean calving interval of 3.12 years (95% confidence interval: 3.07, 3.17). Thesame model produces an estimate for adult female survival rate of 0.983 (95% CI: 0.972, 0.994). The Payne et al. (1990) model is extendedto incorporate information on the observed ages of first reproduction of grey-blazed calves, which are known to be female. This allows theestimation of age at first parturition (median 7.88 years 95% CI 7.17, 9.29). Updates of estimates and confidence intervals for the otherdemographic parameters are: adult female survival rate 0.986 (0.976, 0.999); first year survival rate 0.913 (0.601, 0.994) and instantaneouspopulation increase rate 0.071 (0.059, 0.082). These biological parameter estimates are shown to be compatible with the observed increaserate of the population without the need to postulate immigration.
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- 2020
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3. Mortalities of right whales and related anthropogenic factors in South African waters, 1963-1998
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Victor M. Peddemors, Nan Rice, Peter B. Best, and VG Cockcroft
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Fishery ,education.field_of_study ,biology ,Population ,Animal Science and Zoology ,Aquatic Science ,education ,Crayfish ,Right whale ,biology.organism_classification ,Ecology, Evolution, Behavior and Systematics - Abstract
Between 1963 and 1998, 55 mortalities of southern right whales and a further three ‘possible right whale’ mortalities were recorded on theSouth African coastline. Of the known right whale mortalities, 31 could be classified as ‘calves of the year’, 8 as juveniles and 14 as adults.Relatively few (6.5-16.1%) of the calf mortalities could be attributed to anthropogenic factors, compared to juveniles (25-50%) and adults(35.7-57.1%). Apparent causes of death included ship strikes (4 definite, 7 possible) and entanglement (4 definite, 1 possible), with oneharpooning incident. Five non-fatal ship strikes and 16 instances of non-fatal entanglement were also recorded. Whilst the gear mostcommonly involved in non-fatal entanglement was crayfish trap lines, three of the four entanglement fatalities involved longline gear. Theincidence of scars attributable to previous entanglement remained constant amongst mature females from 1979-1997, at 3-4%. Recordedmortalities increased over the period 1963-1997 at a rate no different from that of population growth over the same period. The current levelof anthropogenic mortality does not seem to be affecting population recovery.
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- 2020
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4. Sightings of southern right whales (Eubalaena australis) in Namibian waters, 1971-1999
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P.E. Stander, Peter B. Best, and J-P. Roux
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Fishery ,Geography ,Aerial survey ,biology ,Range (biology) ,Eubalaena australis ,South east ,Ice calving ,Animal Science and Zoology ,Aquatic Science ,biology.organism_classification ,Ecology, Evolution, Behavior and Systematics - Abstract
Southern right whales were originally abundant in Namibian waters in winter and spring. They were either eradicated from the region ordriven to extremely low numbers more than a century ago. Since 1971, 36 incidental sightings and three aerial surveys confirm the regularpresence of the species within its historical calving range, between June and December. Calving has been recorded in four successive yearsand at least 10 calves were born in the area between 1996 and 1999, confirming the existence of a small established breeding population.This represents a northward extension of the hitherto known modern regular calving range in the South East Atlantic Ocean by more than1,000km.
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- 2020
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5. A note on the age at sexual maturity of humpback whales
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Peter B. Best
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Baleen ,Younger age ,Mortality rate ,Ice calving ,Sexual maturity ,Animal Science and Zoology ,Mean age ,Aquatic Science ,Biology ,Ecology, Evolution, Behavior and Systematics ,Demography - Abstract
The conclusion of researchers in the 1950s that humpback whales reached sexual maturity at about age five was largely influenced by their interpretation of baleen tracings, and to achieve consistency with these tracings the accumulation rate of ear plug laminations (growth layer groups: GLGs) was assumed to be two per year. However, ovulation and natural mortality rates calculated by these researchers under the same assumption produced estimates that are difficult to reconcile with other biological data or with more recent estimates using individual re-sighting data. Such disparities are reduced or disappear when an annual accumulation rate is used, in which case their ear plug data would have indicated a mean age at sexual maturity of 9–11 years. Recent estimates of the age of female humpback whales at first calving using longitudinal studies of photoidentified individuals have produced conflicting results, some (from southeastern Alaska) being compatible with the earlier age-determination studies, others (from the Gulf of Maine) suggesting a much younger age.
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- 2020
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6. Phylogenetic relationships in southern African Bryde’s whales inferred from mitochondrial DNA: further support for subspecies delineation between the two allopatric populations
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Peter B. Best, Philip S. Hammond, Gwenith Susan Penry, Vic Cockcroft, Jefferson A. Graves, Meredith Thornton, University of St Andrews. School of Biology, University of St Andrews. Sea Mammal Research Unit, University of St Andrews. Marine Alliance for Science & Technology Scotland, University of St Andrews. Scottish Oceans Institute, and University of St Andrews. Centre for Research into Ecological & Environmental Modelling
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0106 biological sciences ,0301 basic medicine ,QH301 Biology ,T-NDAS ,Allopatric speciation ,Biodiversity ,Subspecies ,010603 evolutionary biology ,01 natural sciences ,QH301 ,03 medical and health sciences ,biology.animal ,Genetics ,Ecology, Evolution, Behavior and Systematics ,MtDNA control region ,mtDNA control region ,biology ,Whale ,Ecology ,Bryde’s whale ,biology.organism_classification ,Balaenoptera edeni ,Balaenoptera brydei ,Phylogenetics ,030104 developmental biology ,Mammalogy ,Mammal ,Southern Africa - Abstract
Bryde’s whales (Balaenoptera edeni) are medium-sized balaenopterids with tropical and subtropical distribution. There is confusion about the number of species, subspecies and populations of Bryde’s whale found globally. Two eco-types occur off South Africa, the inshore and offshore forms, but with unknown relationship between them. Using the mtDNA control region we investigated the phylogenetic relationship of these populations to each other and other Bryde’s whale populations. Skin, baleen and bone samples were collected from biopsy-sampled individuals, strandings and museum collections. 97 sequences of 674 bp (bp) length were compared with published sequences of Bryde’s whales (n = 6) and two similar species, Omura’s (B. omurai) and sei (B. borealis) whales (n = 3). We found eight haplotypes from the study samples: H1–H4 formed a distinct, sister clade to pelagic populations of Bryde’s whales (B. brydei) from the South Pacific, North Pacific and Eastern Indian Ocean. H5–H8 were included in the pelagic clade. H1–H4 represented samples from within the distributional range of the inshore form. Pairwise comparisons of the percentage of nucleotide differences between sequences revealed that inshore haplotypes differed from published sequences of B. edeni by 4.7–5.5% and from B. brydei by 1.8–2.1%. Ten fixed differences between inshore and offshore sequences supported 100% diagnosability as subspecies. Phylogenetic analyses grouped the South African populations within the Bryde’s-sei whale clade and excluded B. edeni. Our data, combined with morphological and ecological evidence from previous studies, support subspecific classification of both South African forms under B. brydei and complete separation from B. edeni. Postprint
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- 2018
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7. First circumglobal assessment of Southern Hemisphere humpback whale mitochondrial genetic variation and implications for management
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Michael F. Meyer, Lilián Flórez-González, Peter B. Best, Michel Vely, Gianna Minton, Marcia H. Engel, Tim Collins, K. P. Findlay, Muriel Brasseur, Nan Hauser, Claire Garrigue, Carlos Olavarría, C. Scott Baker, John Bannister, Megan Anderson, Francine Kershaw, Matthew S. Leslie, Howard C. Rosenbaum, Cristina Pomilla, Robert Baldwin, Martin Mendez, and M. Michael Poole
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0106 biological sciences ,Management unit ,Ecology ,biology ,010604 marine biology & hydrobiology ,Population structure ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,lcsh:QK1-989 ,Humpback whale ,Fishery ,lcsh:Botany ,Genetic variation ,lcsh:Zoology ,Whaling ,lcsh:QL1-991 ,Southern Hemisphere ,Nature and Landscape Conservation - Abstract
The description of genetic population structure over a species' geographic range can provide insights into its evolutionary history and also support effective management efforts. Assessments for globally distributed species are rare, however, requiring significant international coordination and collaboration. The global distribution of demographically discrete populations for the humpback whale Megaptera novaeangliae is not fully known, hampering the definition of appropriate management units. Here, we present the first circumglobal assessment of mitochondrial genetic population structure across the species' range in the Southern Hemisphere and Arabian Sea. We combine new and existing data from the mitochondrial (mt)DNA control region that resulted in a 311 bp consensus sequence of the mtDNA control region for 3009 individuals sampled across 14 breeding stocks and subpopulations currently recognized by the International Whaling Commission. We assess genetic diversity and test for genetic differentiation and also estimate the magnitude and directionality of historic matrilineal gene flow between putative populations. Our results indicate that maternally directed site fidelity drives significant genetic population structure between breeding stocks within ocean basins. However, patterns of connectivity differ across the circumpolar range, possibly as a result of differences in the extent of longitudinal movements on feeding areas. The number of population comparisons observed to be significantly differentiated were found to diminish at the subpopulation scale when nucleotide differences were examined, indicating that more complex processes underlie genetic structure at this scale. It is crucial that these complexities and uncertainties are afforded greater consideration in management and regulatory efforts.
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- 2017
8. Genetic diversity and connectivity of southern right whales (eubalaena australis) found in the brazil and chile-peru wintering grounds and the south georgia (islas georgias del sur) feeding ground
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Oscar E. Gaggiotti, Timothy R. Frasier, Paulo A. C. Flores, Pavel Hulva, Bárbara Galletti Vernazzani, Jon Seger, Emma L. Carroll, Els Vermeulen, Matthew S. Leslie, Paulo Henrique Ott, Emilie N. Stepien, Susannah Calderan, Thales Renato Ochotorena de Freitas, Russell Leaper, Connor C. G. Bamford, Artur Andriolo, Rachel M. Fewster, Jennifer A. Jackson, Luciano O. Valenzuela, Karina R. Groch, Larissa Rosa de Oliveira, Amy S. Kennedy, Alexandre N. Zerbini, Petra Neveceralova, Louise Fastier McMillan, Andrea D. Chirife, Michael J. Moore, Peter B. Best, Elsa Cabrera, C. Scott Baker, University of St Andrews. School of Biology, University of St Andrews. Sea Mammal Research Unit, University of St Andrews. Scottish Oceans Institute, and University of St Andrews. Marine Alliance for Science & Technology Scotland
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Male ,AcademicSubjects/SCI01140 ,0106 biological sciences ,Conservation genetics ,Genotyping Techniques ,Eubalaena australis ,Jhered/108 ,migration ,Population structure ,01 natural sciences ,Jhered/109 ,Humpback whale ,purl.org/becyt/ford/1 [https] ,Critically endangered ,Eubalaena Glacialis ,Peru ,Chile ,Genetics (clinical) ,Migration ,Humpback Whale ,Islands ,Connectivity ,biology ,Gene flow ,connectivity ,Female ,Brazil ,geographic locations ,Biotechnology ,Zoology ,Context (language use) ,QH426 Genetics ,010603 evolutionary biology ,parasitic diseases ,Genetics ,Animals ,14. Life underwater ,purl.org/becyt/ford/1.6 [https] ,QH426 ,Molecular Biology ,Genetic diversity ,010604 marine biology & hydrobiology ,Whales ,Genetic Variation ,population structure ,DAS ,Feeding Behavior ,Original Articles ,biology.organism_classification ,Phylogeography ,Biological dispersal ,Balaenoptera ,Animal Migration ,gene flow ,Animal Distribution - Abstract
As species recover from exploitation, continued assessments of connectivity and population structure are warranted to provide information for conservation and management. This is particularly true in species with high dispersal capacity, such as migratory whales, where patterns of connectivity could change rapidly. Here we build on a previous long-term, large-scale collaboration on southern right whales (Eubalaena australis) to combine new (nnew) and published (npub) mitochondrial (mtDNA) and microsatellite genetic data from all major wintering grounds and, uniquely, the South Georgia (Islas Georgias del Sur: SG) feeding grounds. Specifically, we include data from Argentina (npub mtDNA/microsatellite = 208/46), Brazil (nnew mtDNA/microsatellite = 50/50), South Africa (nnew mtDNA/microsatellite = 66/77, npub mtDNA/microsatellite = 350/47), Chile-Peru (nnew mtDNA/ microsatellite = 1/1), the Indo-Pacific (npub mtDNA/microsatellite = 769/126), and SG (npub mtDNA/ microsatellite = 8/0, nnew mtDNA/microsatellite = 3/11) to investigate the position of previously unstudied habitats in the migratory network: Brazil, SG, and Chile-Peru. These new genetic data show connectivity between Brazil and Argentina, exemplified by weak genetic differentiation and the movement of 1 genetically identified individual between the South American grounds. The single sample from Chile-Peru had an mtDNA haplotype previously only observed in the Indo-Pacific and had a nuclear genotype that appeared admixed between the Indo-Pacific and South Atlantic, based on genetic clustering and assignment algorithms. The SG samples were clearly South Atlantic and were more similar to the South American than the South African wintering grounds. This study highlights how international collaborations are critical to provide context for emerging or recovering regions, like the SG feeding ground, as well as those that remain critically endangered, such as Chile-Peru. Fil: Carroll, Emma L. University of St. Andrews; Reino Unido Fil: Ott, Paulo H.. Universidade Federal do Rio Grande do Sul; Brasil Fil: McMillan, Louise F.. University Of Wellington; Nueva Zelanda Fil: Vernazzani, Bárbara Galletti. Centro de Conservación Cetacea; Chile Fil: Neveceralova, Petra. Charles University; República Checa Fil: Vermeulen, Els. University Of Pretoria; Sudáfrica Fil: Gaggiotti, Oscar E.. University of St. Andrews; Reino Unido Fil: Andriolo, Artur. Universidade Federal de Juiz de Fora; Brasil Fil: Scott Baker, C.. State University of Oregon; Estados Unidos Fil: Bamford, Connor. British Antarctic Survey; Reino Unido Fil: Best, Peter. University Of Pretoria; Sudáfrica Fil: Cabrera, Elsa. Centro de Conservación Cetacea; Chile Fil: Calderan, Susannah. Scottish Association For Marine Science; Reino Unido Fil: Chirife, Andrea. Universidad Andrés Bello; Chile Fil: Fewster, Rachel M.. University of Auckland; Nueva Zelanda Fil: Flores, Paulo A. C.. No especifíca; Fil: Frasier, Timothy. Saint Marys University; Canadá Fil: Freitas, Thales R.O.. Universidade Federal do Rio Grande do Sul; Brasil Fil: Groch, Karina. Instituto Australis; Brasil Fil: Hulva, Pavel. Charles University; República Checa Fil: Kennedy, Amy. No especifíca; Fil: Leaper, Russell. No especifíca; Fil: Leslie, Matthew S.. No especifíca; Fil: Moore, Michael. No especifíca; Fil: Oliveira, Larissa. Universidade Federal do Rio Grande do Sul; Brasil Fil: Seger, Jon. University of Utah; Estados Unidos Fil: Stepien, Emilie N.. University Aarhus; Dinamarca Fil: Valenzuela, Luciano Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil; Argentina Fil: Zerbini, Alexandre. University of Washington; Estados Unidos Fil: Jackson, Jennifer A.. No especifíca
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- 2020
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9. Multiple processes drive genetic structure of humpback whale (Megaptera novaeangliae) populations across spatial scales
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Solange Ngouessono, Meredith Thornton, Michael F. Meyer, Peter B. Best, Yvette Razafindrakoto, Jacqueline Loo, Marcia H. Engel, Salvatore Cerchio, Cristina Pomilla, Francine Kershaw, Gianna Minton, Howard C. Rosenbaum, P. G. H. Kotze, K. P. Findlay, Inês Carvalho, Peter J. Ersts, Tim Collins, and Jaco Barendse
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0106 biological sciences ,0301 basic medicine ,Genetic diversity ,education.field_of_study ,biology ,Ecology ,Population ,Population genetics ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Humpback whale ,03 medical and health sciences ,030104 developmental biology ,Geographical distance ,Genetic structure ,Genetics ,Biological dispersal ,education ,Ecology, Evolution, Behavior and Systematics ,Isolation by distance - Abstract
Elucidating patterns of population structure for species with complex life histories, and disentangling the processes driving such patterns, remains a significant analytical challenge. Humpback whale (Megaptera novaeangliae) populations display complex genetic structures that have not been fully resolved at all spatial scales. We generated a data set of nuclear markers for 3575 samples spanning the seven breeding stocks and substocks found in the South Atlantic and western and northern Indian Oceans. For the total sample, and males and females separately, we assessed genetic diversity, tested for genetic differentiation between putative populations and isolation by distance, estimated the number of genetic clusters without a priori population information and estimated rates of gene flow using maximum-likelihood and Bayesian approaches. At the ocean basin scale, structure is governed by geographical distance (IBD P
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- 2017
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10. Distribution and seasonal abundance of large cetaceans in the Durban whaling grounds off KwaZulu-Natal, South Africa, 1972–1975
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KP Findlay and Peter B. Best
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0106 biological sciences ,Balaenoptera musculus ,biology ,Eubalaena australis ,business.industry ,010604 marine biology & hydrobiology ,Late winter ,Distribution (economics) ,Aquatic Science ,Seasonality ,biology.organism_classification ,medicine.disease ,010603 evolutionary biology ,01 natural sciences ,Fishery ,Oceanography ,Geography ,Abundance (ecology) ,medicine ,Whaling ,business ,Ecology, Evolution, Behavior and Systematics ,Kwazulu natal - Abstract
Daily charts of the aerial search effort (432 206 nautical miles) of the Union Whaling Company and 1 099 sightings of 10 497 whales were available from 628 flights off Durban between 1972 and 1975. Densities of whales were analysed by month and water depth distribution over the four-year period. Low observed densities of blue Balaenoptera musculus, right Eubalaena australis, sei B. borealis and humpback Megaptera novaeangliae whales most likely resulted from earlier whaling pressure. Seasonality of blue, sei and humpback whales was bimodal, indicative of winter migrations to the north of the Durban whaling grounds, whereas the unimodal seasonality of fin whales B. physalus and minke whales B. bonaerensis or B. acutorostrata suggest the offshore region as the northern terminus of their migrations. Sperm whales Physeter macrocephalus migrate northwards offshore of the KwaZulu-Natal coast in autumn/early winter and southwards in late winter/spring, with larger males migrating later than the smaller males and...
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- 2016
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11. Strong and lasting impacts of past global warming on baleen whale and prey abundance
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Nils Øien, Ken P. Findlay, Luis A. Pastene, Tom Oosting, Lutz Bachmann, Øystein Wiig, Andrea A. Cabrera, Ramp C, Richard Sears, Simon Berrow, Christian Lydersen, Peter B. Best, Kit M. Kovacs, Carolina P. Dias, Mónica A. Silva, Martine Bérubé, Tore Haug, Rui Prieto, Conor Ryan, Jooke Robbins, Finn Larsen, Paspati A, Gísli A. Víkingsson, David K. Mattila, Richard M. Pace, Chiara Papetti, Per J. Palsbøll, Haydée A. Cunha, Scott Landry, Luciano Dalla Rosa, Mads Peter Heide-Jørgensen, P J Clapham, Eduardo R. Secchi, Elena Schall, and Xenia Moreira Lopes
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0106 biological sciences ,010504 meteorology & atmospheric sciences ,Whale ,Ecology ,Global warming ,Biology ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Predation ,Baleen whale ,Baleen ,13. Climate action ,Abundance (ecology) ,biology.animal ,Marine ecosystem ,14. Life underwater ,0105 earth and related environmental sciences ,Trophic level - Abstract
The demography of baleen whales and their prey during the past 30 thousand years was assessed to understand the effects of past rapid global warming on marine ecosystems. Mitochondrial and genome-wide DNA sequence variation in eight baleen whale and seven prey species revealed strong, ocean-wide demographic changes that were correlated with changes in global temperatures and regional oceanographic conditions. In the Southern Ocean baleen whale and prey abundance increased exponentially and in apparent synchrony, whereas changes in abundance varied among species in the more heterogeneous North Atlantic Ocean. The estimated changes in whale abundance correlated with increases in the abundance of prey likely driven by reductions in sea-ice cover and an overall increase in primary production. However, the specific regional oceanographic environment, trophic interactions and species ecology also appeared to play an important role. Somewhat surprisingly the abundance of baleen whales and prey continued to increase for several thousand years after global temperatures stabilized. These findings warn of the potential for dramatic, long-term effects of current climate changes on the marine ecosystem.One Sentence SummaryThe effects of past global warming on marine ecosystems were drastic, system-wide and long-lasting.
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- 2018
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12. Geographical variation in the body size of adult female sperm whales (Physeter macrocephalus) – an example of McNab’s resource rule?
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Peter B. Best, Anabela Brandão, Yuri Mikhalev, Dmitri Tormosov, Marine Resource Assessment and Management Group, and Faculty of Science
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0106 biological sciences ,population difference ,Resource (biology) ,Adult female ,biology ,growth ,010604 marine biology & hydrobiology ,fungi ,latitudinal gradient ,Body size ,resource rule ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Sperm ,Fishery ,Variation (linguistics) ,Sperm whale ,Animal Science and Zoology ,sperm whale ,adult female ,body size ,Ecology, Evolution, Behavior and Systematics - Abstract
This study investigates possible regional variations in size composition of adult female sperm whales (Physeter macrocephalus) using data from 3302 pregnant individuals taken on Soviet whaling expeditions to the Southern Hemisphere 1961/62–1974/75. A general linear model (GLM) was used to take the covariates of expedition, latitude and ocean basin into account. The average body size decreased from south to north in each ocean basin, with the biggest decrease (about 200 cm) in the Indian Ocean; followed by the Pacific Ocean (about 110 cm), and the Atlantic Ocean (about 80 cm). Independent data confirm the small size of female/immature sperm whales in some tropical areas of the Indian and Pacific Oceans. The mechanism responsible for this geographic variation in sperm whale growth could reflect culturally transmitted differences in foraging behaviour between clans of female/immature sperm whales in response to differing availabilities of prey resources by geographical region – McNab’s resource rule. However there is little available information for such a mechanism to be readily identifiable. Although data for oceanic squids (sperm whale’s main source of food) are lacking, there is evidence that the individual sizes of neritic species are positively correlated with latitude. Hence feeding in equatorial regions may be energetically more demanding due to smaller individual prey size, with consequent effects on growth rate.
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- 2016
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13. Does disappearance mean extirpation? The case of right whales off Namibia
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Jean-Paul Roux, Rod J. Braby, and Peter B. Best
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biology ,Eubalaena australis ,Foundation (engineering) ,Commission ,Aquatic Science ,Public administration ,biology.organism_classification ,Corporation ,Environmental protection ,Political science ,World wide fund ,Whaling ,Training programme ,Ecology, Evolution, Behavior and Systematics - Abstract
Benguela Environment Fisheries Interaction & Training Programme (BENEFIT), Namibian Coast Conservation and Management Project (NACOMA), and The Namibia Nature Foundation (NNF).Department of Industries (and its successors), Department of Transport (through the SA National Antarctic Programme), South African Marine Corporation, World Wide Fund for Nature (SA), The Green Trust, Moby Dick Rum, Exclusive Touch, International Whaling Commission, the Island Foundation, and National Research Foundation.
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- 2015
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14. The recovery of North Atlantic right whales, Eubalaena glacialis, has been constrained by human-caused mortality
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Peter J. Corkeron, Claire Charlton, Peter B. Best, Karina R. Groch, Els Vermeulen, John Bannister, Ken P. Findlay, Victoria J. Rowntree, Philip K. Hamilton, and Richard M. Pace
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0106 biological sciences ,Multidisciplinary ,010604 marine biology & hydrobiology ,entanglement mortality ,010603 evolutionary biology ,01 natural sciences ,population projection model ,whale conservation ,Fishery ,Geography ,Abundance (ecology) ,Whaling ,lcsh:Q ,lcsh:Science ,geographical comparison - Abstract
North Atlantic right whales (NARW), Eubalaena glacialis , were nearly exterminated by historical whaling. Their abundance slowly increased up until 2010, to a maximum of fewer than 500 whales, and since then they have been in decline. We assessed the extent to which the relatively slow increase demonstrated by NARW was intrinsic, and how much could be due to anthropogenic impacts. In order to do so, we first compared calf counts of three populations of Southern right whales (SRW), E. australis , with that of NARW, over the period 1992–2016. By this index, the annual rate of increase of NARW was approximately one-third of that of SRW. Next we constructed a population projection model for female NARW, using the highest annual survival estimates available from recent mark–resight analysis, and assuming a four-year calving interval. The model results indicated an intrinsic rate of increase of 4% per year, approximately twice that observed, and that adult female mortality is the main factor influencing this rate. Necropsy records demonstrate that anthropogenic mortality is the primary cause of known mortality of NARW. Anthropogenic mortality and morbidity has limited the recovery of NARW, and baseline conditions prior to their recent decline were already jeopardizing NARW recovery.
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- 2018
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15. Near-shore distribution of Heaviside’s (Cephalorhynchus heavisidii) and dusky dolphins (Lagenorhynchus obscurus) at the southern limit of their range in South Africa
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Peter B. Best, Desray Reeb, Meredith Thornton, and Simon Harvey Elwen
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Fishery ,biology ,Hake ,Cephalorhynchus heavisidii ,Fishing ,Dusky dolphin ,Lagenorhynchus ,Animal Science and Zoology ,biology.organism_classification ,Bay ,Diel vertical migration ,Merluccius capensis - Abstract
Photo-identification surveys over three years along 390 km of coastline north of Cape Town, revealed that Heaviside’s dolphin distribution was consistent between years and higher in areas more exposed to swells and with greater long-term availability of small hake Merluccius capensis (their principal prey). Dusky dolphin sighting rates varied considerably between years, but were generally higher in areas with lower hake availability and sandier shores (mostly straighter coastline). Large groups of 50–200 dusky dolphins were only seen in St Helena Bay, the site of a wind-driven upwelling zone. Heaviside’s dolphins were found in shallower, cooler water than dusky dolphins and were more likely to be seen during brighter phases of the moon (when nocturnal light conditions may influence the vertical migration patterns of prey) and in areas of high hake abundance. Near-shore fishing activity was higher in the northern half of the study area and clustered around harbours. Set netting occurred only at Yzerfontein and St Helena Bay, but due to changes in the industry is currently thought to be a low threat to the population. Interactions between Heaviside’s and dusky dolphins were usually neutral and sympatry appears to be mediated by differences in overall range and the type and size of prey species taken.African Zoology 45(1): 78–91 (April 2010)
- Published
- 2017
16. Humpback whales off Namibia: occurrence, seasonality, and a regional comparison of photographic catalogs and scarring
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Tess Gridley, Jaco Barendse, Ruth H. Leeney, Simon Harvey Elwen, Howard C. Rosenbaum, Nicoló Tonachella, Peter B. Best, and Tim Collins
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Ecology ,biology ,Population structure ,Seasonality ,Tail fluke ,medicine.disease ,biology.organism_classification ,Dorsal fin ,Mark and recapture ,Fishery ,Humpback whale ,Geography ,Genetics ,medicine ,Animal Science and Zoology ,West coast ,Ecology, Evolution, Behavior and Systematics ,Isistius ,Nature and Landscape Conservation - Abstract
Humpback whales (Megaptera novaeangliae) from a breeding ground off Gabon (0–4°S) and a migratory corridor/feeding ground on the west coast of South Africa (WSA; 33°S) differ genetically and in catch histories. Interpretation of the population structure is hampered by the lack of data from the intervening 3,500 km of coastline or to the north of Gabon. Here we collate all relevant nongenetic data on humpback whales from Namibia (∼23°S) from 2005 to 2012 and compare these with corresponding data from Gabon (2000–2006) and WSA (1983–2008). Data from Namibia include photographic catalogs of dorsal fin and tail fluke images, seasonal presence, and a photographic assessment of scarring and wounds from cookiecutter sharks (Isistius sp.). No confirmed photographic identification matches could be made between Namibia and Gabon and only 2 potential matches were made between Namibia and WSA from dorsal fins. Humpback whales in Namibia show a bimodal seasonality in occurrence, with a primary peak in austral...
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- 2014
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17. Tag retention, wound healing, and subsequent reproductive history of southern right whales following satellite-tagging
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Peter B. Best, Barbara A. Lagerquist, and Bruce R. Mate
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biology ,Satellite telemetry ,Eubalaena australis ,Ecology ,Aquatic Science ,biology.organism_classification ,Aquatic organisms ,Marine mammal ,Geography ,Marine fisheries ,Reproductive history ,Right whale ,Naval research ,Ecology, Evolution, Behavior and Systematics - Abstract
U.S. National Marine Fisheries Service, Office of Naval Research and gifts from donors to the Oregon State University Marine Mammal Program.
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- 2014
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18. Confirmation of the occurrence of a second killer whale morphotype in South African waters
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G. J. G. Hofmeyr, Dirk Steinke, P. G. H. Kotze, S Wintner, SM Seakamela, CD Weland, Meredith Thornton, Peter B. Best, and Matthias Meyer
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Appendage ,Morphometrics ,Dentition ,biology ,Ecology ,Whale ,Prionace glauca ,Aquatic Science ,biology.organism_classification ,Predation ,Dorsal fin ,Tooth wear ,biology.animal ,Ecology, Evolution, Behavior and Systematics - Abstract
Killer whales Orcinus orca occur worldwide in a number of morphotypes that differ in size, pigmentation, acoustic behaviour, food type and genetics – some may indeed warrant subspecific or even specific status. Until recently, all killer whales in South African waters were referred to a single morphotype, Type A, but three individuals (two males and one female) that have stranded since 1969 differ in several respects from other killer whales examined from the region. Adult length is some 1–1.5 m smaller, appendages such as dorsal fin and flippers tend to be relatively larger, and tooth wear is excessive. Although dietary information is scant, one stomach contained the remains of several elasmobranchs, identified from a DNA subsample as blue sharks Prionace glauca, a dietary item that, if habitual, might account for the tooth wear. This morphotype, referred to here as ‘flat-toothed’ and which in several respects resembles the offshore form in the North Pacific and the Type 1 form in the North Atlantic, doe...
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- 2014
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19. Shore-based observations of seasonality, movements, and group behavior of southern right whales in a nonnursery area on the South African west coast
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Peter B. Best and Jaco Barendse
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Shore ,geography ,geography.geographical_feature_category ,Aerial survey ,biology ,Ecology ,Range (biology) ,Eubalaena australis ,Aquatic Science ,Seasonality ,medicine.disease ,biology.organism_classification ,Oceanography ,Habitat ,medicine ,Right whale ,Bay ,Ecology, Evolution, Behavior and Systematics - Abstract
The southern right whale’s (Eubalaena australis) demography, occurrence, habitat use, and behavior off South Africa are known predominantly from an ongoing aerial survey data set that started in 1971. The fixed timeframes of these surveys and their geographical bias towards south coast nursery areas have constrained our knowledge about the right whale’s seasonal distribution elsewhere. We present shore-based observations and tracking of right whales at Saldanha Bay on the west coast (2001– 2003) that reveal a near year-round presence and strongly nearshore distribution. With seasonal progression from winter to summer we observed a gradual increase in sighting rate, reduction in swimming speed, less directionality of movement, an increase in group size, and more surface active groups. The area appears to be important for feeding and socializing but not as a calving or nursery area. Individual transits between the south and west coasts, bidirectional alongshore movements, and extended seasonal presence may all be indicative of reoccupation of their former range along the west coast. This is important given the increasing ship traffic at Saldanha Bay, the rapid expansion of the region’s oil and gas industry, and the known vulnerability of the closely related North Atlantic right whale (E. glacialis )t o ship strikes.
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- 2014
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20. Does temporal and spatial segregation explain the complex population structure of humpback whales on the coast of West Africa?
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Inês Carvalho, Howard C. Rosenbaum, Solange Ngouessono, Tim Collins, Peter B. Best, Jacqueline Loo, Cristina Pomilla, Jaco Barendse, and Matthew S. Leslie
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Fishery ,Spatial segregation ,Ecology ,Population structure ,Genetic data ,Whaling ,Aquatic Science ,Biology ,Selective breeding ,Ecology, Evolution, Behavior and Systematics ,West africa ,Genetic differentiation - Abstract
Humpback whales (Megaptera novaeangliae) in the Southeastern Atlantic Ocean (International Whaling Commission ‘Breeding Stock B’—BSB) are distributed from the Gulf of Guinea to Western South Africa. Genetic data suggest that this stock may be sub-structured, but it remains unknown if this is due to reproductive segregation. This paper evaluates the spatial and temporal population structure of BSB humpback whales using a combination of maternally and bi-parentally inherited markers. The genetic differentiation that we identify in this study could be due to a combination of (1) spatial and/or temporal segregation on breeding grounds in the greater Gulf of Guinea, (2) the possibility of maternally inherited site fidelity to specific feeding grounds and (3) the use of two generalized but exclusive migratory routes (coastal and offshore) between feeding and breeding areas. Further, photo-identification and genetic sampling efforts in other areas of the Sub-Saharan Western Africa winter range and targeted deployment of satellite tags would help to clarify some of the apparent complexity in the population structure of animals biopsied in this region.
- Published
- 2014
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21. A leopard seal from Hout Bay, South Africa
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Peter B. Best
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Fishery ,Geography ,biology ,biology.animal ,Leopard ,Seal (mechanical) ,Bay - Abstract
(1971). A Leopard Seal from Hout Bay, South Africa. Zoologica Africana: Vol. 6, No. 2, pp. 177-179.
- Published
- 2017
22. Pygmy right whaleCaperea marginatarecords from Namibia
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Peter B. Best, Ruth H. Leeney, C.J. Hazevoet, K. Post, and Simon Harvey Elwen
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Pygmy right whale ,Fishery ,Geography ,biology ,Fauna ,High incidence ,Aquatic Science ,biology.organism_classification ,Bay ,Ecology, Evolution, Behavior and Systematics - Abstract
All known records of pygmy right whales Caperea marginata in Namibia since 1978 are summarised for the first time, including 12 strandings (live and recently dead animals) and skeletal remains from at least eight more individuals. The majority of strandings and remains were located in the Walvis Bay region, where the coastal topography of the bay and lagoon may be a primary cause for the relatively high incidence of strandings in this area. Strandings appear to occur only during the austral summer, between November and March. All but two of the records for which age is available were juveniles, suggesting that the area offshore of Walvis Bay may function as a seasonal nursery ground and that the inexperience of younger animals may cause them to become ‘entrapped’ in the bay. These data contribute substantially to the limited information on pygmy right whale distribution worldwide and the cetacean fauna of Namibia.
- Published
- 2013
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23. False killer whales (Pseudorca crassidens) from Japan and South Africa: Differences in growth and reproduction
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Peter B. Best, Ines Maria Ferreira, Toshio Kasuya, and Helene Marsh
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Pseudorca crassidens ,Physical Maturity ,Ecology ,media_common.quotation_subject ,False Killer Whales ,Zoology ,Aquatic Science ,Biology ,biology.organism_classification ,Pregnancy rate ,Sexual maturity ,Reproduction ,Ecology, Evolution, Behavior and Systematics ,media_common - Abstract
Age and reproductive information for 65 false killer whales stranded in South Africa in 1981 are compared with similar material from 156 animals examined from drive fisheries in Japan in 1979 and 1980. Sizes at birth, sexual maturation, and physical maturity all indicated that both sexes were 10%–20% larger in Japan than South Africa. Females reached sexual maturation at similar ages (8–10.5 yr) in both populations, and although sample sizes were too small to establish male ages at puberty precisely the ranges in Japan (10.5–18.5 yr) and South Africa (5.25–17.5 yr) were not inconsistent. The initial ovulation rate for females from South Africa was 65% lower (and the apparent pregnancy rate 82% lower) than those from Japan and there were fewer animals �2 yr old within the school, but the magnitude of these differences suggests that the stranded school’s reproductive performance was probably impaired. Collectively these comparisons and the literature indicate substantive size differences between false killer whales in different populations, although the patterns of growth appear similar. Firm conclusions about any geographical differences in reproduction require additional data.
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- 2013
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24. Evidence for a postreproductive phase in female false killer whales Pseudorca crassidens
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Peter B. Best, Theoni Photopoulou, Toshio Kasuya, Ines Maria Ferreira, Helene Marsh, and University of St Andrews. School of Biology
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0106 biological sciences ,0301 basic medicine ,Pseudorca crassidens ,QH301 Biology ,False Killer Whales ,media_common.quotation_subject ,Odontocete ,Zoology ,010603 evolutionary biology ,01 natural sciences ,Pilot whale ,False killer whale ,Life history theory ,QH301 ,03 medical and health sciences ,biology.animal ,lcsh:Zoology ,lcsh:QL1-991 ,Quantitative Biology - Populations and Evolution ,Ecology, Evolution, Behavior and Systematics ,media_common ,QL ,biology ,Whale ,Reproduction ,Populations and Evolution (q-bio.PE) ,Family Delphinidae ,DAS ,QL Zoology ,biology.organism_classification ,030104 developmental biology ,FOS: Biological sciences ,Animal Science and Zoology ,Mammal ,Postreproductive lifespan - Abstract
A substantial period of life after reproduction ends, known as postreproductive lifespan (PRLS), is at odds with classical life history theory. Prolonged PRLS has been confirmed in only two non-human mammals, both odontocete cetaceans. We investigate the evidence for PRLS in a third species, the false killer whale, Pseudorca crassidens, using a quantitative measure of PRLS and morphological evidence from reproductive tissue. We examined specimens from false killer whales from combined strandings (South Africa, 1981) and harvest (Japan 1979-80) and found morphological evidence of changes in the activity of the ovaries in relation to age. Ovulation had ceased in 50% of whales over 45 years, and all whales over 55 years old had ovaries classified as postreproductive. We also calculated a measure of PRLS, known as postreproductive representation (PrR) as an indication of the effect of inter-population demographic variability. PrR for the combined sample was 0.14, whereas the mean of the simulated distribution for PrR under the null hypothesis of no PRLS was 0.02. The 99th percentile of the simulated distribution was 0.08 and no simulated value exceeded 0.13. These results suggest that PrR was convincingly different from the measures simulated under the null hypothesis. We found morphological and statistical evidence for PRLS in South African and Japanese pods of false killer whales, suggesting that this species is the third non-human mammal in which this phenomenon has been demonstrated in wild populations. Our estimates for PrR in false killer whales (0.12-0.37) spanned the single values available for the short-finned pilot whale (0.28) and the killer whale (0.22) and are comparable to estimates for historical or hunter-gather human populations (0.3-0.47)., 22 pages, 5 figures, 9 additional files
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- 2016
25. Evidence for a postreproductive phase in female false killer whales
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Theoni, Photopoulou, Ines M, Ferreira, Peter B, Best, Toshio, Kasuya, and Helene, Marsh
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Research ,Reproduction ,Odontocete ,Postreproductive lifespan ,False killer whale - Abstract
Background A substantial period of life after reproduction ends, known as postreproductive lifespan (PRLS), is at odds with classical life history theory and its causes and mechanisms have puzzled evolutionary biologists for decades. Prolonged PRLS has been confirmed in only two non-human mammals, both odontocete cetaceans in the family Delphinidae. We investigate the evidence for PRLS in a third species, the false killer whale, Pseudorca crassidens, using a quantitative measure of PRLS and morphological evidence from reproductive tissues. Results We examined specimens from false killer whales from combined strandings (South Africa, 1981) and harvest (Japan 1979-80) and found morphological evidence of changes in the activity of the ovaries in relation to age. Ovulation had ceased in 50% of whales over 45 years, and all whales over 55 years old had ovaries classified as postreproductive. We also calculated a measure of PRLS, known as postreproductive representation (PrR) as an indication of the effect of inter-population demographic variability. PrR for the combined sample was 0.14, whereas the mean of the simulated distribution for PrR under the null hypothesis of no PRLS was 0.02. The 99th percentile of the simulated distribution was 0.08 and no simulated value exceeded 0.13. These results suggest that PrR was convincingly different from the measures simulated under the null hypothesis. Conclusions We found morphological and statistical evidence for PRLS in South African and Japanese pods of false killer whales, suggesting that this species is the third non-human mammal in which this phenomenon has been demonstrated in wild populations. Nonetheless, our estimate for PrR in false killer whales (0.14) is lower than the single values available for the short-finned pilot whale (0.28) and the killer whale (0.22) and is more similar to working Asian elephants (0.13). Electronic supplementary material The online version of this article (doi:10.1186/s12983-017-0208-y) contains supplementary material, which is available to authorized users.
- Published
- 2016
26. Identifying the 'demon whale-biter' : patterns of scarring on large whales attributed to a cookie-cutter shark Isistius sp
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Theoni Photopoulou, Peter B. Best, University of St Andrews. School of Biology, Department of Statistical Sciences, and Faculty of Science
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Male ,0106 biological sciences ,QH301 Biology ,Marine and Aquatic Sciences ,Predation ,lcsh:Medicine ,01 natural sciences ,Animal Cells ,Medicine and Health Sciences ,lcsh:Science ,Chondrichthyes ,Mammals ,Latitude ,Multidisciplinary ,Ecology ,Geography ,biology ,Agricultural and Biological Sciences(all) ,Stomach ,Fishes ,Killer Whales ,Trophic Interactions ,Community Ecology ,Habitat ,Vertebrates ,Female ,Cellular Types ,Anatomy ,Isistius ,Research Article ,Cartography ,Food Chain ,Zoology ,Marine Biology ,010603 evolutionary biology ,Cicatrix ,QH301 ,biology.animal ,Sperm whale ,Animals ,Whaling ,SDG 14 - Life Below Water ,Marine Mammals ,Sperm Whales ,Sperm Whale ,Balaenoptera ,Whale ,Biochemistry, Genetics and Molecular Biology(all) ,010604 marine biology & hydrobiology ,Ecology and Environmental Sciences ,lcsh:R ,Organisms ,Whales ,Biology and Life Sciences ,DAS ,Cell Biology ,biology.organism_classification ,Sperm ,Gastrointestinal Tract ,Germ Cells ,Predatory Behavior ,Amniotes ,Sharks ,Earth Sciences ,Sperm Head ,lcsh:Q ,Digestive System ,Bay ,Elasmobranchii - Abstract
The presence of crater-like wounds on cetaceans and other large marine vertebrates and invertebrates has been attributed to various organisms. We review the evidence for the identity of the biting agent responsible for crater wounds on large whales, using data collected from sei (Balaenoptera borealis), fin (B. physalus), inshore and offshore Bryde's (B. brydeii sp) and sperm whales (Physeter macrocephalus) examined at the Donkergat whaling station, Saldanha Bay, South Africa between March and October 1963. We then analyse the intensity and trends in its predation on large whales. Despite the scarcity of local records, we conclude that a cookie-cutter shark Isistius sp is the most likely candidate. We make inferences about the trends in (1) total counts of unhealed bitemarks, and (2) the proportion of unhealed bitemarks that were recent. We use day of the year; reproductive class, social grouping or sex; depth interval and body length as candidate covariates. The models with highest support for total counts of unhealed bitemarks involve the day of the year in all species. Depth was an important predictor in all species except offshore Bryde's whales. Models for the proportion of recent bites were only informative for sei and fin whales. We conclude that temporal scarring patterns support what is currently hypothesized about the distribution and movements of these whale species, given that Isistius does not occur in the Antarctic and has an oceanic habitat. The incidence of fresh bites confirms the presence of Isistius in the region. The lower numbers of unhealed bites on medium-sized sperm whales suggests that this group spends more time outside the area in which bites are incurred, providing a clue to one of the biggest gaps in our understanding of the movements of mature and maturing sperm males. Publisher PDF
- Published
- 2016
27. Identification of stomach contents from a Shepherd's beaked whale Tasmacetus shepherdi stranded on Tristan da Cunha, South Atlantic
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James P. Glass, Peter B. Best, Malcolm J. Smale, K. Herian, and S von der Heyden
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Fishery ,biology ,Tasmacetus ,Ethnology ,%22">Fish ,Shepherd's beaked whale ,Aquatic Science ,biology.organism_classification - Abstract
Shepherd's beaked whale Tasmacetus shepherdi is one of the most poorly known cetaceans, whose diet has created some speculation given that its dentition differs greatly from that of most other beaked whales that are primarily teuthophagous. The few stomachs examined previously have given seemingly conflicting dietary information. In this paper the stomach contents of a freshly stranded adult female on Tristan da Cunha have been examined through identification of trace elements and genetic analysis of soft parts. At least 13 cephalopod and 8 fish species were identified from beaks and otoliths respectively, but only undigested fish remains were present in the stomach and identified genetically as Beryx splendens. Reconstituted masses totaled 8809 g for cephalopods and 17,554 g for fish, with four species (Histioteuthis atlantica, Taningia danae, Ommastrephes bartrami and Pholidoteuthis ‘A’) comprising 78.6% of the cephalopods and one species (B. splendens) comprising 87.4% of the fish eaten. It is concluded that Tasmacetus may alternately exploit fish and cephalopods, depending on the time of day and access to seamount or continental slope areas.
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- 2012
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28. Body shape changes associated with reproductive status, nutritive condition and growth in right whales Eubalaena glacialis and E. australis
- Author
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Michael J. Moore, Peter B. Best, Mark F. Baumgartner, Carolyn A. Miller, and Wayne L. Perryman
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Fishery ,Oceanography ,Ecology ,biology ,Marine fisheries ,Aquatic Science ,Right whale ,biology.organism_classification ,Ecology, Evolution, Behavior and Systematics ,Body condition - Abstract
The National Oceanic and Atmospheric Administration (NOAA), National Marine Fisheries Service, the Northeast Consortium, and the Hussey Foundation through the Ocean Life Institute at Woods Hole Oceanographic Institution.
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- 2012
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29. Movement patterns of coastal bottlenose dolphins in the presence of a fast-flowing, prevailing current: shore-based observations at Cape Vidal, South Africa
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Peter B. Best, Theoni Photopoulou, PS Hammond, and K. P. Findlay
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Shore ,geography ,geography.geographical_feature_category ,biology ,Aquatic Science ,Agulhas current ,biology.organism_classification ,Bottlenose dolphin ,Humpback whale ,Current (stream) ,Fishery ,Oceanography ,Cape ,Tursiops aduncus ,Ecology, Evolution, Behavior and Systematics - Abstract
The presence and movement of Indo-Pacific bottlenose dolphins Tursiops aduncus were investigated using shore-based observations made during a humpback whale Megaptera novaeangliae migration survey at Cape Vidal, South Africa, undertaken between June and October 1988–1991. Occurrence was analysed as counts of dolphin sightings per hour within a generalised estimating equation framework. Bottlenose dolphin sightings decreased throughout the daily survey period, and there was a small seasonal peak in sightings during August. Data on movement trajectory were collected using a theodolite for 60% of the groups of dolphins sighted. Most groups were observed travelling in a northerly direction, with few groups recorded moving south. A generalised linear model indicated that northwardtravelling dolphins were located closer to shore, travelled at higher speeds, and occurred in bigger groups under low-tide conditions, than those seen moving in a southerly direction. The southwardflowing Agulhas Current is close to shore at Cape Vidal, where the continental shelf is particularly narrow. We suggest that bottlenose dolphins in this area have adopted a specific movement regime to cope with the consistent fast-flowing currents that dominate their environment at Cape Vidal. Keywords: Agulhas Current, generalised estimating equation, generalised linear model, sightings, theodolite, Tursiops aduncusAfrican Journal of Marine Science 2011, 33(3): 393–401
- Published
- 2011
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30. Transit station or destination? Attendance patterns, movements and abundance estimate of humpback whales off west South Africa from photographic and genotypic matching
- Author
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Peter B. Best, Howard C. Rosenbaum, Inês Carvalho, Cristina Pomilla, Simon Harvey Elwen, Tim Collins, Jaco Barendse, Meredith Thornton, Ruth H. Leeney, and Matthias Meyer
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Matching (statistics) ,biology ,Aquatic Science ,Seasonality ,medicine.disease ,biology.organism_classification ,Dorsal fin ,Humpback whale ,Fishery ,Mark and recapture ,Geography ,Oceanography ,Abundance (ecology) ,Photo identification ,medicine ,Ecology, Evolution, Behavior and Systematics ,Ventral tail - Abstract
Humpback whales Megaptera novaeangliae found off west South Africa (WSA) are known to display an atypical migration that may include temporary residency and feeding during spring and summer. At a regional scale there is uncertainty about how these whales relate to the greater West African Breeding Stock B as a whole, with evidence both for and against its division into two substocks. A database containing sighting information of humpback whales intercepted by boat in the WSA region from 1983 to 2008 was compiled. It included a total of 1 820 identification images of ventral tail flukes and lateral views of dorsal fins. After systematic within- and between-year matching of images of usable quality, it yielded 154 different individuals identified by tail flukes (TF), 230 by left dorsal fins (LDF), and 237 by right dorsal fins (RDF). Microsatellite (MS) matching of 216 skin biopsies yielded 156 individuals. By linking all possible sightings of the same individuals using all available identification features, the periodicity and seasonality of 281 individual whales were examined. In all, 60 whales were resighted on different days of which 44 were between different calendar years. The most resightings for one individual was 11 times, seen in six different years, and the longest interval between first and last sightings was about 18 years. A resighting rate of 15.6% of whales at intervals of a year or more indicates long-term fidelity to the region. Shorter intervals of 1–6 months between sequential sightings in the same year may suggest temporary residency. The TF image collection from WSA was compared to TF collections from four other regions, namely Gabon, Cabinda (Angola), Namibia and the Antarctic Humpback Whale Catalogue (AHWC). Three matches were detected between WSA (in late spring or summer) and Gabon (in winter), confirming direct movement between these regions. The capture–recapture data of four different identification features (TF, RDF, LDF and MS) from six successive subsets of data from periods with the highest collection effort (2001–2007) were used to calculate the number of whales that utilise the region, using both closed- and open-population models. Dorsal fins have never been used to estimate abundance for humpback whales, so the different identification features were evaluated for potential biases. This revealed 9–14% incidence of missed matches (false negatives) when using dorsal fins that would result in an overestimate, whereas variation in individual fluke-up behaviour may lower estimates by as much as 57–66% due to heterogeneity of individual capture probability. Taking into consideration the small dataset and low number of recaptures, the most consistent and precise results were obtained from a fully time-dependent version of the Jolly-Seber open-population model, with annual survival fixed at 0.96, using the MS dataset. This suggests that the WSA feeding assemblage during the months of spring and summer (September–March) of the study period numbered about 500 animals. The relationship of these whales to those (perhaps strictly migratory) that may occur in other seasons of the year, and their links to possible migratory routes and other feeding or breeding areas, remain uncertain.Keywords: abundance, Breeding Stock B, capture heterogeneity, capture–recapture, Chapman’s modified Petersen estimate, Megaptera novaeangliae, migration, photo-identification, Program MARK, site fidelityAfrican Journal of Marine Science 2011, 33(3): 353–373
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- 2011
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31. Acoustic behaviour of southern right whales in relation to numbers of whales present in Walker Bay, South Africa
- Author
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Peter B. Best and L.H. Hofmeyer-Juritz
- Subjects
Geography ,Oceanography ,biology ,Eubalaena australis ,Foundation (engineering) ,Wildlife ,Aquatic Science ,Relation (history of concept) ,biology.organism_classification ,Bay ,Ecology, Evolution, Behavior and Systematics - Abstract
The National Research Foundation, the Worldwide Fund for Nature, South Africa (WWF SA), PetroSA (formerly Soekor), the Wildlife and Environment Society of South Africa and Spescom,.
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- 2011
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32. Blubber thickness in right whales Eubalaena glacialis and Eubalaena australis related with reproduction, life history status and prey abundance
- Author
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Carolyn A. Miller, Desray Reeb, Moira W. Brown, Amy R. Knowlton, Michael J. Moore, and Peter B. Best
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Ecology ,biology ,Eubalaena australis ,media_common.quotation_subject ,Calanus finmarchicus ,Zoology ,Aquatic Science ,biology.organism_classification ,Predation ,Fishery ,Blubber ,Juvenile ,Reproduction ,Right whale ,Bay ,Ecology, Evolution, Behavior and Systematics ,media_common - Abstract
The high variability in reproductive performance of North Atlantic right whales Eubal- aena glacialis compared to southern right whales Eubalaena australis may reflect differences in lipid reserves. Amplitude-mode ultrasound was used to measure the thickness of right whale integument (epidermis and blubber, herein referred to as blubber thickness) in E. glacialis in the Bay of Fundy, Canada for 5 summer seasons and in E. australis off the South African coast for 2 austral winter sea- sons. E. glacialis had significantly thinner blubber layers (mean ±1 SD = 12.23 ± 2.16 cm, n = 172) than E. australis (16.13 ± 3.88 cm, n = 117), suggesting differing levels of nutrition between the 2 species. Blubber was thickest in females measured 3 to 6 mo prior to the start of pregnancy (E. glacialis), thin- ner during lactation (E. glacialis, E. australis) and then thicker with time after weaning (E. glacialis). These results suggest that lipids in blubber are used as energetic support for reproduction in female right whales. Blubber thickness increased in calves during suckling (E. glacialis, E. australis) but sub - sequently decreased after weaning (E. glacialis). Juvenile and adult male E. glacialis blubber thick- nesses were compared between years of differing prey Calanus finmarchicus abundances (data from Pershing et al. 2005; ICES J Mar Sci 62:1511-1523); during a year of low prey abundance whales had significantly thinner blubber than during years of greater prey abundance. Taken together, these re- sults suggest that blubber thickness is indicative of right whale energy balance and that the marked fluctuations in North Atlantic right whale reproduction have a nutritional component.
- Published
- 2011
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33. Killer whales in South African waters—a review of their biology
- Author
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Peter B. Best, MA Meÿer, and C Lockyer
- Subjects
Data deficient ,Morphometrics ,biology ,Ecotype ,Whale ,Ecology ,media_common.quotation_subject ,Aquatic Science ,Seasonality ,medicine.disease ,biology.animal ,medicine ,Whaling ,Reproduction ,Predator ,Ecology, Evolution, Behavior and Systematics ,media_common - Abstract
The distribution, seasonality and schooling behaviour of killer whales Orcinus orca in South African waters have been investigated from 785 records compiled between 1963 and 2009, and their size, morphometrics, growth, reproduction, food and feeding behaviour described from the examination of 54 individuals, 36 of which were landed at the Durban whaling station between 1971 and 1975. Qualitatively, the species appears to be more frequently encountered offshore, where it forms small schools of generally less than six animals. Seasonality of occurrence is not marked, although circumstantial evidence indicates that some individuals migrate from higher latitudes. Males reach 8.81 m and females 7.9 m, with 16.2% of males exceeding the size of the largest female. Stomach content and observational data suggest that the species can be characterised locally as an opportunistic predator of megavertebrates, rather than as the fish-feeding ecotype previously described. A stranded adult male with extreme tooth wear that was 1.5–2 m shorter than other males of equivalent age may be representative of a separate ‘offshore’ ecotype. Apparent differences between features of the popu lation’s life history and those of resident killer whales in the north-eastern Pacific might be attributed to either uncertainties in age determination using dentinal growth layer groups or sampling bias. The basis for the suggestion that killer whales in South African waters should be reclassified as Vulnerable (rather than Data Deficient) is challenged. Keywords: distribution, feeding, growth, killer whale, morphometrics, Orcinus orca, reproduction, South Africa African Journal of Marine Science 2010, 32(2): 171–186
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- 2010
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34. Fungi associated with the skin of a southern right whale (Eubalaena australis) from South Africa
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Desray Reeb, Alfred Botha, Peter B. Best, Karen J. Cloete, Meredith Thornton, and Marnel Mouton
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integumentary system ,biology ,Eubalaena australis ,Mucocutaneous zone ,Zoology ,Aquatic animal ,biology.organism_classification ,Microbiology ,Infectious Diseases ,medicine.anatomical_structure ,Botany ,Stratum corneum ,medicine ,Colonization ,Epidermis ,Stratum spinosum ,Right whale - Abstract
Cutaneous fungi are known to affect parts of the outermost skin layers of mammals, including the epidermis, stratum spinosum and stratum corneum, as well as mucocutaneous membranes, genitalia or external ears. Relatively little is known about fungal infections of Mysticete cetaceans and studies are needed to determine the fungal diversity associated with these marine mammals. This case report was aimed at identifying the fungi associated with the skin of a diseased neonatal southern right whale (Eubalaena australis) found stranded in the Western Cape Province of South Africa. Initial physical examination on site revealed hyperplasia of the follicular and epidermal epithelium. Preliminary examination of skin biopsies using scanning electron microscopy indicated that the skin was colonized by fungal hyphae. Isolation methods yielded a number of fungal isolates, which were identified using standard morphology and rDNA sequence data. These analyses confirmed colonization of the cutaneous layers by sp...
- Published
- 2010
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35. Coastal, offshore, and migratory movements of South African right whales revealed by satellite telemetry
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Peter B. Best, Bruce R. Mate, Martha H. Winsor, and Barbara A. Lagerquist
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biology ,Eubalaena australis ,Ecology ,Satellite telemetry ,Foraging ,Foundation (engineering) ,Aquatic Science ,biology.organism_classification ,Fishery ,Geography ,Marine mammal ,Submarine pipeline ,Naval research ,Administration (government) ,Ecology, Evolution, Behavior and Systematics - Abstract
P. B. B. acknowledges the support of the National Research Foundation of South Africa (GUN number 2047517). B. R. M. acknowledges the support of the National Oceanic and Atmospheric Administration through the Northeast Consortium, based at the University of New Hampshire (Grant #NA16FL1324), the U.S. Office of Naval Research, and donors to the Oregon State University Endowed Marine Mammal Program.
- Published
- 2010
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36. A near mass stranding of cetaceans in St Helena Bay, South Africa
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Peter B. Best and D Reeb
- Subjects
Fishery ,Pseudorca crassidens ,Geography ,biology ,False Killer Whales ,Grampus griseus ,Aquatic Science ,biology.organism_classification ,Bottlenose dolphin ,Bay ,Ecology, Evolution, Behavior and Systematics - Abstract
A group of 70 false killer whales Pseudorca crassidens and 124 bottlenose dolphins Tursiops sp., and a separate group of 13 Risso's dolphins Grampus griseus, assembled close inshore off a known mass-stranding site in St Helena Bay, South Africa, in October 2003. However, only a single Risso's dolphin attempted to strand and 13 bottlenose dolphins had to be shepherded out of the shallows the next day, the remainder leaving of their own accord. This is considered to be the first near-stranding phenomenon recorded for the region.
- Published
- 2010
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37. Migration redefined? Seasonality, movements and group composition of humpback whalesMegaptera novaeangliaeoff the west coast of South Africa
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Meredith Thornton, Cristina Pomilla, Jaco Barendse, Howard C. Rosenbaum, Peter B. Best, and Inês Carvalho
- Subjects
Shore ,geography.geographical_feature_category ,biology ,Anomaly (natural sciences) ,Aquatic Science ,Seasonality ,biology.organism_classification ,medicine.disease ,Predation ,Humpback whale ,Fishery ,Geography ,Oceanography ,medicine ,West coast ,Bay ,Southern Hemisphere ,Ecology, Evolution, Behavior and Systematics - Abstract
The migration of Southern Hemisphere humpback whales Megaptera novaeangliae between their feeding and breeding areas has thus far been considered a highly predictable and seasonal event. However, previous observations on the humpbacks that pass through the nearshore waters of the west coast of South Africa have revealed deviations from the behaviour and seasonality expected during a typical migration. This ‘anomaly’ is hypothesised to be associated with prey availability in the region. Shore-based observations between July 2001 and February 2003 from North Head, Saldanha Bay, in the Western Cape province, yielded relative abundances that again did not support a classical migration pattern, with the highest sighting rates from mid-spring through summer. Movement parameters (actual swimming speed, direction and linearity) of humpback groups tracked by theodolite showed mid-spring to be a turning point in their behaviour, after which we observed a significant reduction in actual swimming speed, an increase i...
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- 2010
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38. A population estimate of Heaviside's dolphins,Cephalorhynchus heavisidii, at the southern end of their range
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Desray Reeb, Meredith Thornton, Simon Harvey Elwen, and Peter B. Best
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education.field_of_study ,biology ,Range (biology) ,Ecology ,Population ,Cetacea ,Aquatic Science ,biology.organism_classification ,Mark and recapture ,Fishery ,Cephalorhynchus ,Geography ,Abundance (ecology) ,Cephalorhynchus heavisidii ,Netting ,education ,Ecology, Evolution, Behavior and Systematics - Abstract
Heaviside's dolphins, Cephalorhynchus heavisidii, are endemic to southwestern Africa, where they are exposed to unknown levels of anthropogenic threats, including inshore set netting. Using photo-ID data collected over 3 yr on the west coast of South Africa, we calculated Chapman's-modified Petersen estimates of the number of distinctive individuals at three spatial scales. Sample sizes were small and recapture rates low resulting in high variance. Total population abundance was extrapolated from the proportion of well-marked animals in the population (14%-17%) with between-year estimates adjusted for mortality using data from Commerson's dolphin. The total population size was calculated as 527 animals (CV = 0.35, CI 272-1,020) in the 1999 study area (20 km of coastline, within season), 3,429 animals (CV = 0.36, CI 1,721-6,828) in the central study area (150 km of coast-line, 3 yr), and 6,345 animals (CV = 0.26, CI 3,573-11,267) in the full study area (390 km of coastline, 2 yr). Dolphins fitted with satellite transmitters varied in their use of the inshore photographic study area from 39.5% to 94.7% of transmission days (38-51 total). Given the known or suspected biases in the data, these abundance estimates are likely to be biased downward.
- Published
- 2009
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39. Nineteenth-century evidence for the Golfo de Panama as a migratory destination for southern humpback whales, including the first mention of singing
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Peter B. Best
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Fishery ,Panama ,Geography ,biology ,Cetacea ,Aquatic Science ,Singing ,biology.organism_classification ,Ecology, Evolution, Behavior and Systematics - Published
- 2008
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40. Structure of the integument of southern right whales,Eubalaena australis
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Susan H. Kidson, Peter B. Best, and Desray Reeb
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Male ,Histology ,Toothed whale ,Eubalaena australis ,Baleen whale ,Microscopy, Electron, Transmission ,Species Specificity ,Skin Physiological Phenomena ,biology.animal ,medicine ,Animals ,Ecology, Evolution, Behavior and Systematics ,integumentary system ,biology ,Whale ,Whales ,Anatomy ,biology.organism_classification ,medicine.anatomical_structure ,Animals, Newborn ,Microscopy, Electron, Scanning ,Female ,Integument ,Epidermis ,Integumentary System ,Right whale ,Rorqual ,Biotechnology - Abstract
Skin (integument) anatomy reflects adaptations to particular environments. It is hypothesized that cetacean (whale) integument will show unique anatomical adaptations to an aquatic environment, particularly regarding differences in temperature, density, and pressure. In this study, the gross and histological structure of the southern right whale integument is described and compared with terrestrial mammals and previous descriptions of mysticete (baleen whale) and odontocete (toothed whale) species. Samples were taken of the integument of 98 free-swimming southern right whales, Eubalaena australis, and examined by both light and electron microscopy. Results show that three epidermal layers are present, with the stratum corneum being parakeratotic in nature. As in bowhead whales, southern right whales possess an acanthotic epidermis and a notably thick hypodermis, with epidermal rods and extensive papillomatosis. However, unlike bowhead whales, southern right whales possess an uninterrupted hypodermal layer. Surprisingly, the integument of balaenids (right and bowhead mysticetes) in general is more like that of odontocetes than that of the more closely related balaenopterids (rorqual mysticetes). Similarities to odontocetes were found specifically in the collagen fibers in a fat-free zone of the reticular dermal layer and the elastic fibers in the dermal and hypodermal layers. Callosities, a distinctive feature of this genus, have a slightly thicker stratum corneum and are usually associated with hairs that have innervated and vascularized follicles. These hairs may function as vibrissae, thus aiding in aquatic foraging by allowing rapid detection of changes in prey density. Although the thick insulatory integument makes right whales bulky and slow-moving, it is an adaptation for living in cold water. Epidermal thickness, presence of epidermal rods, and callosities may act as barriers against mechanical injury from bodily contact with conspecifics or hard surfaces in the environment (e.g., rocks, ice).
- Published
- 2007
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41. Possible non-offspring nursing in the southern right whale, Eubalaena australis
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Per J. Palsbøll, Simon Harvey Elwen, Katja Vinding, Meredith Thornton, Peter B. Best, Evan Austin, and Palsbøll lab
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AFRICA ,LACTATION ,Offspring ,Eubalaena australis ,media_common.quotation_subject ,CALF ,Genetics ,medicine ,Ecology, Evolution, Behavior and Systematics ,Nature and Landscape Conservation ,media_common ,MOVEMENTS ,Ecology ,Adult female ,biology ,Seasonality ,biology.organism_classification ,medicine.disease ,SEASONALITY ,REPRODUCTION ,Geography ,COASTAL DISTRIBUTION ,PATTERNS ,Animal Science and Zoology ,ABUNDANCE ,GLACIALIS ,Reproduction ,Right whale ,Demography - Abstract
During the austral winter, adult female southern right whales Eubalaena australis enter the South African coastal waters to give birth and raise their young. Most births take place over a 4-month period, when the females congregate in specific coastal areas or nursery grounds for up to a recorded maximum of 105 days. At this time, the density of cowtextendashcalf pairs in nursery areas can reach as high as 3.2 pairs/km2 over 26 km of coastline. Although a single young is born and suckled exclusively for 7 months to a year, recent observations on nursery grounds include 3 incidents where apparently abandoned/orphaned calves-of-the-year have been seen associating with a minimum of 2textendash3 different cowtextendashcalf pairs over periods of 11textendash38 days. Attempts to suckle from these females have been noted in 2 of the cases, with the response of the female varying from extreme avoidance to apparent tolerance. In one instance where the observations of the same trio extended over 21 days, the non-offspring appeared to compete at least equally with the offspring, even though the mother directed her evasive tactics more at the non-offspring than her own calf. At the same time, both of the calves exhibited some growth in length when compared with the size of the adult female: their subsequent survival is unknown. Non-offspring nursing in monotocous species is generally rare, and the costs to the female potentially high: this is certainly the case for seasonally feeding mysticetes such as the right whale, where the costs of lactation cannot be recovered until the cow resumes feeding about 4 months after parturition. Hence, it is perhaps not surprising that these are the first recorded observations of contemporaneous nursing attempts by offspring and non-offspring calves of any mysticete.Key Words
- Published
- 2015
42. RANGE AND MOVEMENTS OF FEMALE HEAVISIDE'S DOLPHINS (CEPHALORHYNCHUS HEAVISIDII), AS DETERMINED BY SATELLITE-LINKED TELEMETRY
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Meredith Thornton, Simon Harvey Elwen, P. G. H. Kotze, Michael A. Meÿer, Peter B. Best, and Stephan Swanson
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Shore ,geography.geographical_feature_category ,Ecology ,biology ,Range (biology) ,Home range ,Cetacea ,biology.organism_classification ,Merluccius capensis ,Fishery ,Geography ,Cephalorhynchus ,Hake ,Cephalorhynchus heavisidii ,Genetics ,Animal Science and Zoology ,Ecology, Evolution, Behavior and Systematics ,Nature and Landscape Conservation - Abstract
Heaviside’s dolphin (Cephalorhynchus heavisidii) is a coastal delphinid with a limited inshore distribution off the west coast of southern Africa. Knowledge of its habitat usage is an essential precursor to assessing its potential vulnerability to fisheries interactions. Six Heaviside’s dolphins (1 male and 5 females) were fitted with satellitelinked transmitters in 2004, and tracked for up to 54 days. The 5 tags fitted to female dolphins transmitted continuously, allowing for analysis of movements at a fine temporal scale. Four dolphins showed an initial avoidance of the capture site by moving over a wider area in the first 2–5 days posttagging than later in the deployment period. All dolphins had used their full home ranges (determined as 100% minimum convex polygons) 5–20 days before tag failure, suggesting measured home ranges were stable at this temporal scale. Home-range estimates using local convex hulls ranged from 301.9 to 1,027.6 km 2 (90% isopleths) and 875.9 to 1,989.6 km 2 using the 100% isopleths and scaled positively with body size but varied in shape, usage, and number of core-use areas. Although the distance from shore and depth at which individual dolphins moved varied greatly, all dolphins showed a strong onshore–offshore diurnal movement pattern, generally being closest inshore between 0600 h and noon, and farthest offshore between 1500 h and 0500 h. This pattern is assumed to be related to the movements of their principal prey, juvenile shallow-water hake (Merluccius capensis), which migrate into the upper water column at night. Movements inshore may be associated with rest, socializing, and predator avoidance.
- Published
- 2006
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43. SHEPHERD'S BEAKED WHALE (TASMACETUS SHEPHERDI): INFORMATION ON APPEARANCE AND BIOLOGY BASED ON STRANDINGS AND AT-SEA OBSERVATIONS
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A. Pym, Peter B. Best, Anton L. van Helden, and Robert L. Pitman
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Beak ,Aquatic environment ,Tasmacetus ,Zoology ,Shepherd's beaked whale ,Aquatic Science ,Biology ,biology.organism_classification ,Ecology, Evolution, Behavior and Systematics - Abstract
), one of the least known cetaceans intheworld(Mead1989,2002),iscurrentlyrepresentedbyapproximately42strandingrecordsand5unconfirmedlivesightings.MostofthestrandingshavebeenfromNewZealand (including the Chatham Islands—24 records), but also the Juan FernandezIslands(2),Argentina(7),TristandaCunha(6),andAustralia(3)(Fig.1).Astrandingreported from the South Sandwich Islands (Mead 2002) was actually a “probable”at-sea sighting near Shag Rocks (position of sighting: 53
- Published
- 2006
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44. Population histories of right whales (Cetacea: Eubalaena) inferred from mitochondrial sequence diversities and divergences of their whale lice (Amphipoda: Cyamus)
- Author
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Mariano Sironi, Catherine M. Schaeff, Nathalie J. Patenaude, Moira W. Brown, Amy R. Knowlton, Rafael Benegas, Jon Seger, Susan G. Barco, Tadasu K. Yamada, Robert L. Brownell, Victoria J. Rowntree, Robert Harcourt, Peter B. Best, Kim Marshall-Tilas, Wendy A. Smith, Alejandro Carribero, Zofia A. Kaliszewska, and Mariana Rivarola
- Subjects
Eubalaena australis ,Molecular Sequence Data ,Population Dynamics ,Population ,Cetacea ,DNA, Mitochondrial ,Host-Parasite Interactions ,Evolution, Molecular ,Species Specificity ,Effective population size ,biology.animal ,Genetics ,Animals ,Amphipoda ,education ,Ecology, Evolution, Behavior and Systematics ,DNA Primers ,Population Density ,Likelihood Functions ,education.field_of_study ,Base Sequence ,Geography ,Models, Genetic ,biology ,Ecology ,Whale ,Whales ,Genetic Variation ,Sequence Analysis, DNA ,biology.organism_classification ,Eubalaena japonica ,Genetics, Population ,Population bottleneck ,Right whale - Abstract
Right whales carry large populations of three ‘whale lice’ ( Cyamus ovalis , Cyamus gracilis , Cyamus erraticus ) that have no other hosts. We used sequence variation in the mitochondrial COI gene to ask (i) whether cyamid population structures might reveal associations among right whale individuals and subpopulations, (ii) whether the divergences of the three nominally conspecific cyamid species on North Atlantic, North Pacific, and southern right whales ( Eubalaena glacialis, Eubalaena japonica, Eubalaena australis ) might indicate their times of separation, and (iii) whether the shapes of cyamid gene trees might contain information about changes in the population sizes of right whales. We found high levels of nucleotide diversity but almost no population structure within oceans, indicating large effective population sizes and high rates of transfer between whales and subpopulations. North Atlantic and Southern Ocean populations of all three species are reciprocally monophyletic, and North Pacific C. erraticus is well separated from North Atlantic and southern C. erraticus . Mitochondrial clock calibrations suggest that these divergences occurred around 6 million years ago (Ma), and that the Eubalaena mitochondrial clock is very slow. North Pacific C. ovalis forms a clade inside the southern C. ovalis gene tree, implying that at least one right whale has crossed the equator in the Pacific Ocean within the last 1–2 million years (Myr). Low-frequency polymorphisms are more common than expected under neutrality for populations of constant size, but there is no obvious signal of rapid, interspecifically congruent expansion of the kind that would be expected if North Atlantic or southern right whales had experienced a prolonged population bottleneck within the last 0.5 Myr.
- Published
- 2005
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45. Polymorphic microsatellite loci isolated from humpback whale, Megaptera novaeangliae and fin whale, balaenoptera physalus
- Author
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Mary Beth Rew, Hanne Jørgensen, Hans J. Skaug, Peter B. Best, Martine Bérubé, Richard Sears, Per J. Palsbøll, and Jooke Robbins
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Humpback whale ,biology ,Balaenoptera ,Evolutionary biology ,Ecology ,Whale ,biology.animal ,Genetics ,Str loci ,Microsatellite ,biology.organism_classification ,Ecology, Evolution, Behavior and Systematics ,Baleen whale - Abstract
Key words: baleen whale, kinship, Mysteceti, STR lociInconservationgenetics,itisbecomingincreasinglyclear that parameters derived over evolutionarytime scales may not apply to much shorter ecolog-ical timescales (Palsboll 1999). Molecular geneticmethods can be employed to estimate parametersonanecological timescale ifthe focusis aimedonlyat recently diverged lineages, i.e., among individu-als as opposed to among populations. Theseextensions of current approaches are vital to alignthe application of molecular genetics to contem-porary issues in conservation. In order to estimatethe degree of kinship in a reliable manner, an ade-quate number of loci must be analyzed per indi-vidual. Ensuring an adequate number of locidecreases/eliminates the interference of other levelsof relatives, and compensates for the exponentialincrease in the number of pair-wise comparisonswhen the sample size increases. Towards this end,we presented, in this note, an additional 17 poly-morphic microsatellite loci, which, originated froma di-, tri- and tetra-nucleotide microsatellite locienriched library constructed from humpbackwhale, Megaptera novaeangliae, and fin whale,Balaenoptera physalus, genomic DNA, using theprotocol previously described in Palsboll et al.(1997) and Be´rube´et al. (2000).More specifically, the microsatellite loci wereisolated from size-selected total-cell DNAextracted from humpback whale and fin whaleusing the approach described by Rassmann andcolleagues (1991). Recombinant colonies (dotblotted to a ZetaProbe
- Published
- 2005
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46. EVIDENCE OF POSTNATAL ECDYSIS IN SOUTHERN RIGHT WHALES, EUBALAENA AUSTRALIS
- Author
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Desray Reeb, Maureen Duffield, and Peter B. Best
- Subjects
Ecology ,Eubalaena australis ,Mechanical integrity ,Anatomy ,Biology ,medicine.disease ,biology.organism_classification ,Edema ,Ecdysis ,Genetics ,medicine ,Animal Science and Zoology ,medicine.symptom ,Right whale ,Ecology, Evolution, Behavior and Systematics ,Volume concentration ,Nature and Landscape Conservation ,Spongiosis - Abstract
This paper presents evidence of the presence and subsequent loss of postnatal skin in an ecdysis-like process in southern right whales, Eubalaena australis. Individuals whose skin was noticeably uneven, spongy, broken, and often light gray in color formed >20% of right whale neonates seen on the South African coast on any day up to and including the 1st week of September. Thereafter >85% of calves were of the normal, smooth-skinned appearance. The 50% transition point between the 2 forms occurred on 31 August (95% CI 1.1 days), or about a week after birth. Histological analysis of skin from stranded neonates showed a definite cleavage plane in the midepidermis, the mechanical integrity of which was further compromised by low concentrations of desmosomes and intracellular filaments. We propose that focal edema develops between the cells and forms the cleavage plane, which eventually leads to separation of the outer epidermal cell layer (cf. spongiosis in humans). The movement from the intrauterine to the oceanic milieu, and the osmoregulatory consequences thereof, may be a catalytic factor for this process to occur. This ecdysis may have important consequences for the cyamid fauna of neonatal right whales.
- Published
- 2005
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47. Evidence for male dispersal along the coasts but no migration in pelagic waters in dusky dolphins (Lagenorhynchus obscurus)
- Author
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Peter B. Best, Enrique Alberto Crespo, Athanasia C. Tzika, Koen Van Waerebeek, Insa Cassens, Michel C. Milinkovitch, and Anton L. van Helden
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biology ,Ecology ,Population size ,Cetacea ,biology.organism_classification ,Gene flow ,Phylogeography ,Genetic drift ,Genetics ,Biological dispersal ,Dusky dolphin ,Lagenorhynchus ,human activities ,Ecology, Evolution, Behavior and Systematics - Abstract
Using nine nuclear species-specific microsatellite loci and two mitochondrial gene fragments (cytochrome b and control region), we investigated the processes that have shaped the geographical distribution of genetic diversity exhibited by contemporary dusky dolphin ( Lagenorhynchus obscurus ) populations. A total of 221 individuals from four locations (Peru, Argentina, southern Africa, and New Zealand) were assayed, covering most of the species’ distribution range. Although our analyses identify a general demographic decline in the Peruvian dusky dolphin stock (recently affected by high natural and humaninduced mortality levels), comparison between the different molecular markers hint at an ancient bottleneck that predates recent El Nino oscillations and human exploitation. Moreover, we find evidence of a difference in dispersal behaviour of dusky dolphins along the South American coast and across the Atlantic. While data in Peruvian and Argentine waters are best explained by male-specific gene flow between these two populations, our analyses suggest that dusky dolphins from Argentina and southern Africa recently separated from an ancestral Atlantic population and, since then, diverged without considerable gene flow. The inclusion of a few New Zealand samples further confirms the low levels of genetic differentiation among most dusky dolphin populations. Only the Peruvian dusky dolphin stock is highly differentiated, especially at mitochondrial loci, suggesting that major fluctuations in its population size have led to an increased rate of genetic drift.
- Published
- 2004
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48. ENVIRONMENTAL FACTORS INFLUENCING THE DISTRIBUTION OF SOUTHERN RIGHT WHALES (EUBALAENA AUSTRALIS) ON THE SOUTH COAST OF SOUTH AFRICA II: WITHIN BAY DISTRIBUTION
- Author
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Peter B. Best and Simon Harvey Elwen
- Subjects
biology ,Whale ,Eubalaena australis ,Ecology ,Cetacea ,Pelagic zone ,Aquatic Science ,biology.organism_classification ,Balaenidae ,Oceanography ,Geography ,Habitat ,biology.animal ,Right whale ,Bay ,Ecology, Evolution, Behavior and Systematics - Abstract
Environmental factors are thought to strongly influence the distribution and predictability of the coastal distribution of southern right whales (Eubalaena australis) off South Africa. Preferred habitat had generally shallow sloping sedimentary floors and was characteristically protected from open ocean swell and prevalent seasonal winds. This study investigated whether habitat choices at smaller scales (within bays) were similar. Fine scale distribution patterns (GPS) from three years’ surveys (1997, 1999, 2000) were analyzed separately within the three main concentration areas St Sebastian Bay, De Hoop, and Walker Bay (containing -73% of cow-calf pairs and -49% of unaccompanied adults in the whole survey region). Whale density at this scale of within particular bays did not correlate well with predicted variables, but Chi-squared analysis strongly supported results at broader scales, in all bays. Post-hoc “choice” tests between similar areas differing in only one variable revealed that cow-calves preferred (presumed) sandy substrates and especially protection from swell. The strength and predictability of preferences shown at fine scale (where individual movement and weather variability could have great influence) provide strong support for findings at larger scales and emphasize the importance of environmental factors in the habitat choice of wintering right whales.
- Published
- 2004
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- View/download PDF
49. ENVIRONMENTAL FACTORS INFLUENCING THE DISTRIBUTION OF SOUTHERN RIGHT WHALES (EUBALAENA AUSTRALIS) ON THE SOUTH COAST OF SOUTH AFRICA I: BROAD SCALE PATTERNS
- Author
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Peter B. Best and Simon Harvey Elwen
- Subjects
Shore ,geography.geographical_feature_category ,biology ,Whale ,Ecology ,Eubalaena australis ,Cetacea ,Pelagic zone ,Aquatic Science ,biology.organism_classification ,Balaenidae ,Swell ,Geography ,Oceanography ,biology.animal ,Right whale ,Ecology, Evolution, Behavior and Systematics - Abstract
Aerial surveys over the last 32 yr have shown that the distribution of southern right whales Eubalaena australis along the south coast of South Africa is markedly discontinuous, but highly predictable. A GIS was used at a variety of scales to investigate whether this pattern was related to environmental characteristics. Whale distribution was analyzed as density per 20-min bin of longitude over two temporal and spatial scales, namely 15 bins for 32 yr, and a wider scale but shorter time period, 23 bins for 19 yr, as well as using three years of GPS accuracy data (15 bins) for finer scale analysis. Environmental factors tested were depth, distance from shore, sea floor slope, protection from swell, protection from wind, and shore type. The majority of whales were concentrated in areas that provided reasonable protection from open ocean swell and seasonal winds, and had sedimentary floors with gentle slopes. They generally avoided exposed rocky shorelines. Cow-calf pairs were found significantly closer to shore and in shallower water than unaccompanied whales, particularly off sandy beaches. Habitat choice at this time of year may be related both to energy conservation for calves and lactating females (calm sea conditions) and to protection of the new-born.
- Published
- 2004
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50. Female southern right whales Eubalaena australis: Are there reproductive benefits associated with their coastal distribution off South Africa?
- Author
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Peter B. Best and Simon Harvey Elwen
- Subjects
Ecology ,biology ,Reproductive success ,Eubalaena australis ,media_common.quotation_subject ,Environmental factor ,Ice calving ,Aquatic Science ,biology.organism_classification ,Spatial distribution ,medicine.disease_cause ,Animal science ,medicine ,Philopatry ,Reproduction ,Right whale ,Ecology, Evolution, Behavior and Systematics ,media_common - Abstract
Predictability in both meso- and microscale distribution of southern right whale Euba- laena australis females off the coast of South Africa is attributed to maternal philopatry, as well as favourable environmental conditions (calm water, generally shallow sloping, sedimentary sea bed) conducive to reduced energy consumption and a lowered risk of injury for both cows and calves. Spa- tial differences in reproductive success were compared between favoured (nursery) and non- favoured (non-nursery) areas and related to environmental differences in those areas. Reproductive success was inferred from analysis of calving intervals (3 yr = successful, 2 and 4 yr = unsuccessful; n= 808 calving events). Resighting rates as well as differences in distribution between experienced cows (3 or more calves) and inexperienced cows (1 or 2 calves) were also analysed. Less experienced cows were found to have significantly more unsuccessful calving intervals than experienced cows. No relationship was found between calving success and spatial distribution using calving interval analysis. Significant spatial differences in stranding rates of neonatal calves strongly suggest higher rates of calf mortality in areas dominated by non-cows, independent of environmental conditions. Social structure within wintering grounds was concluded to be more important than previously thought and potentially as important as environmental conditions for calf survival.
- Published
- 2004
- Full Text
- View/download PDF
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