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The rediscovery of the Takahe Porphyrio hochstetteri in 1948 in the remote mountains of Fiordland, New Zealand, has been described as one of the greatest moments in ornithological history. The subsequent management of the population has become a model for avian recovery programmes, yet questions still remain regarding the population size at the time of, and prior to, its rediscovery. We used 20 microsatellite markers to genotype samples of the three surviving museum specimens (1849-1898) collected prior to the initial declaration of extinction to estimate levels of genetic diversity and effective population size. These estimates were compared with equivalent estimates from DNA samples of three specimens preserved at the time of rediscovery (1949) and with 20 contemporary samples. Using rarefaction simulations to account for the limited sample sizes, the results suggest that only slightly more genetic diversity (allelic diversity and numbers of polymorphic loci) existed in the earliest Takahe sampled and that levels of genetic diversity at the time of rediscovery were very similar to those today. Effective population size estimates showed a similar pattern. Contemporary samples from a widespread congener to Takahe, the Pukeko Porphyrio porphyrio, showed consistently higher levels of genetic diversity and greater effective population size, even after equivalent rarefaction to the same small sample sizes available for Takahe. It is likely that the population size of Takahe in Fiordland at the time of European arrivals in the 1800s was similar to its current size. These results provide molecular support for the hypothesis that Takahe were common throughout most coastal and eastern parts of the South Island of New Zealand before being hunted to extinction in these regions by early Maori, and persisted as a relatively small and isolated population in Fiordland where they may never have been very common. This is in marked contrast to other New Zealand endemic birds found in Fiordland, such as the Kakapo Strigops habroptilus and several forest passerines, which remained relatively numerous until the time of European arrival before undergoing rapid declines thereafter. [ABSTRACT FROM AUTHOR]

The maintenance of genetic diversity is thought to be fundamental for the conservation of threatened species. It is therefore important to understand how genetic diversity is affected by the re-introduction of threatened species. We use establishment history and genetic data from the remnant and re-introduced populations of a New Zealand endemic bird, the hihi Notiomystis cincta, to understand genetic diversity loss and quantify the genetic effects of re-introduction. Our data do not support any recent bottleneck events in the remnant population. Furthermore, all genetic diversity measures indicate the remnant hihi population has retained high levels of genetic diversity relative to other New Zealand avifauna with similar histories of decline. Genetic diversity ( N, alleles per locus, allelic richness, F and H) did not significantly decrease in new hihi populations founded through re-introduction when compared to their source populations, except in the Kapiti Island population (allelic richness and H) which had very slow post-re-introduction population growth. The N /N ratio in the remnant population was high, but decreased in first-level re-introductions, which together with significant genetic differentiation between populations ( F & Fisher's exact tests) suggest that extant populations are diverging as a result of founder effects and drift. Importantly, simulations of future allele loss predict that the number of alleles lost will be higher in populations with a slow population growth, fewer founding individuals and with nonrandom mating. Interestingly, this species has very high levels of extra-pair paternity which may reduce reproductive variance by allowing social and floater males to reproduce a life history trait that together with a large remnant population size may help maintain higher levels of genetic diversity than expected. [ABSTRACT FROM AUTHOR]

The endangered Cook's petrel ( Pterodroma cookii) is restricted to two separated populations at the extremes of its former range across New Zealand. Prior work revealed morphological, foraging, and reproductive isolation between these two remnant populations. To aid the conservation management of the species, additional information is required on the genetic structure of Cook's petrel. We used mitochondrial DNA sequences (Cytochrome Oxidase subunit 1 gene), collected from 26 and 19 Cook's petrel breeding on Little Barrier Island (LBI) and Codfish Island (CDF), respectively, for this preliminary study. We uncovered distinct population genetic structure with analysis of molecular variance suggesting genetic isolation of the populations. Levels of genetic variation were higher in the LBI population (four haplotypes present; h = 0.34 and π = 0.10) whereas the CDF population had only one haplotype that was distinct from the LBI population. Our results indicate that Cook's petrel constitute two distinct management units for which conservation of genetic as well as behavioural and morphological diversity should be a priority. Further genetic studies using nuclear markers are recommended. [ABSTRACT FROM AUTHOR]

The ship rat or black rat ( Rattus rattus) is one of the most widespread invasive rodent species on earth, and is a known cause of extinction of several endemic species in invaded ecosystems. While some information is available for insular populations, very little is known about the genetic population structure of this species on mainland areas. In this study (the first to characterize genetic population structure of invasive R. rattus on the mainland), we focused on the population structure of rats located in Puketi Forest Conservation Reserve, Northland, New Zealand, to help conservation managers optimize control programs. We used eight microsatellite markers and classical population genetics tools ( F, clustering methods) as well as individual-based descriptive methods using GPS coordinates for each sample (Genetic Landscape Shape, Bandwidth Mapping) in order to determine whether there was any undetected genetic structure over the 5-km area. Very little genetic structure was detected. Nevertheless, a weak but significant isolation-by-distance pattern was inferred. No isolation with external sites (encompassing an area up to 20 km) was found, suggesting the presence of a contiguous population at an even larger scale, presumably by exchanging genes mainly between neighbours. We discuss the implications of these findings in terms of management of ship rats to protect native biodiversity. [ABSTRACT FROM AUTHOR]

There is an increasing awareness that the longterm viability of endemic island populations is negatively affected by genetic factors associated with population bottlenecks and/or persistence at small population size. Here we use contemporary samples and historic museum specimens (collected 1888-1938) to estimate the effective population size (Ne) for the endangered yellow-eyed penguin (Megadyptes antipodes) in South Island, New Zealand, and evaluate the genetic concern for this iconic species. The South Island population of M. antipodes- constituting almost half of the species' census size-is thought to be descended from a small number of founders that reached New Zealand just a few hundred years ago. Despite intensive conservation measures, this population has shown dramatic fluctuations in size over recent decades. We compare estimates of the harmonic mean Ne for this population, obtained using one moment and three likelihood based-temporal methods, including one method that simultaneously estimates migration rate. Evaluation of the Ne estimates reveals a harmonic mean Ne in the low hundreds. Additionally, the inferred low immigration rates (m = 0.003) agree well with contemporary migration rate estimates between the South Island and subantarctic populations of M. antipodes. The low Ne of South Island M. antipodes is likely affected by strong fluctuations in population size, and high variance in reproductive success. These results show that genetic concerns for this population are valid and that the long-term viability of this species may be compromised by reduced adaptive potential. [ABSTRACT FROM AUTHOR]

The inference of demographic parameters from genetic data has become an integral part of conservation studies. A group of Bayesian methods developed originally in population genetics, known as approximate Bayesian computation (ABC), has been shown to be particularly useful for the estimation of such parameters. These methods do not need to evaluate likelihood functions analytically and can therefore be used even while assuming complex models. In this paper we describe the ABC approach and identify specific parts of its algorithm that are being the subject of intensive studies in order to further expand its usability. Furthermore, we discuss applications of this Bayesian algorithm in conservation studies, providing insights on the potentialities of these tools. Finally, we present a case study in which we use a simple Isolation- Migration model to estimate a number of demographic parameters of two populations of yellow-eyed penguins (Megadyptes antipodes) in New Zealand. The resulting estimates confirm our current understanding of M. antipodes dynamic, demographic history and provide new insights into the expansion this species has undergone during the last centuries. [ABSTRACT FROM AUTHOR]

In reptiles, phenotypic measures such as body size usually predict a male's success in territorial interactions. Recent evidence from fish, birds, and mammals has shown that genetic heterozygosity also has a strong influence on competitive ability and territory quality. Here, we provide a comprehensive assessment of the social structure and factors affecting male territory quality and aggressive behavior in a dense population of Tuatara, a long-lived reptile that maintains long-term territories, on Stephens Island, New Zealand. The only significant predictor of female access and competitive ability was male body size, and there was no relationship between male body size or condition and individual genetic heterozygosity. Body size, body condition, and heterozygosity did not predict territory size. Also, heterozygosity, body condition, and territory size had no relationship with the number of females to which a male had access. Large males were more effective at (1) monopolizing areas where females were most dense and (2) guarding females by consistently winning aggressive encounters with other males. Our finding of no relationship between territoriality and heterozygosity probably reflects the genetic background of this large, outbred population or that behavioral attributes or neutral heterozygosity are not appropriate individual fitness correlates for these long-lived reptiles. [ABSTRACT FROM AUTHOR]

We investigated the possibility that variation in ovine ADRB3 is associated with various wool traits, in particular mean staple strength (MSS). Polymerase chain reaction-single strand conformational polymorphism analysis of part of the ADRB3 intron was used to genotype 695 Merino lambs born on three farms in the South Island of New Zealand and which were shorn as 2-tooths. For each fleece, MSS, mean fibre diameter, mean staple length and yield were measured. The results from mixed-effects models and half-sib analyses suggest that ADRB3 alleles A and D have a negative impact on some wool traits, whereas ADRB3 alleles C and E appear to have a positive impact, with allele C potentially having a greater impact than allele E on MSS. This variation in the ADRB3 may assist in the genetic selection for increased MSS and yield in Merino sheep. [ABSTRACT FROM AUTHOR]

The article discusses a study which aims to estimate larval dispersal times between the Chatham Islands and Sub-Antarctic Islands in New Zealand and find out whether the Cellana strigilis genetics explains these dispersal times. The study provides a general description of the circulation around New Zealand and shows computed dispersal distances as a function of time. It concludes that larval dispersal is a manifestation of the mean circulation and genetic connectivity appears within island pairs.

The article discusses a study which investigates the genetic connectivity and phylogeographic structure of Cellana strigilis or intertidal limpets from the Chatham Islands and Sub-Antarctic Islands in New Zealand. In this study, three mitochondrial genes are used to examine the genetic structure of Cellana strigilis. It discovers that the genetic homogeneity observed among populations of two lineages proposes that these populations are isolated. It suggests that the population genetic structure details the difficulties in relating genetic structure with gene flow and population connectivity.

Abstract: Numerous globally abundant species are exposed to human impacts that threaten the viability of regional populations. Assessing and characterising the risks faced by these populations can have significant implications for biodiversity conservation, given the ecological importance of many such species. To address these risks, the IUCN is starting to conduct assessments of regional populations in addition to species-level assessments of conservation status. Here, we demonstrate a threat assessment process that is robust to uncertainty, applying the IUCN criteria to a regional population of bottlenose dolphins in Fiordland, New Zealand. We compiled available population-specific information to assess the population under the five Red List criteria. We estimated there were 205 Fiordland bottlenose dolphins (CV=3.5%), using current estimates of abundance for two sub-populations and stochastic modelling of an earlier estimate for the third sub-population. Population trajectory and extinction risk were assessed using stochastic age-structured Leslie matrix population models. The majority of model runs met the criteria for classification as critically endangered (C1: 67.6% of runs) given the number of mature individuals (123; CV=6.7%) and the predicted rate of population decline (average decline: 31.4% over one generation). The evidence of isolation of the population confirms this was an appropriate regional classification. This approach provided an assessment that was robust to uncertainty. [Copyright &y& Elsevier]

Five polymorphic microsatellite loci were developed and then used to assess the population genetic structure of a commercially harvested merobenthic octopus species ( Octopus maorum) in south-east Australian and New Zealand (NZ) waters. Beak and stylet morphometrics were also used to assess population differentiation in conjunction with the genetic data. Genetic variation across all loci and all sampled populations was very high (mean number alleles = 15, mean expected heterozygosity = 0.85). Microsatellites revealed significant genetic structuring (overall FST = 0.024, p < 0.001), which did not fit an isolation-by-distance model of population differentiation. Divergence was observed between Australian and NZ populations, between South Australia and north-east Tasmania, and between two relatively proximate Tasmanian sites. South Australian and southern Tasmanian populations were genetically homogeneous, indicating a level of connectivity on a scale of 1,500 km. Morphometric data also indicated significant differences between Australian and NZ populations. The patterns of population structuring identified can be explained largely in relation to regional oceanographic features. [ABSTRACT FROM AUTHOR]

In this study we investigate the geographic distribution, genetic diversity, and phylogenetic relationships of an endangered tick, Amblyomma sphenodonti (Family Ixodidae). Amblyomma sphenodonti and its host, the tuatara (Sphenodon), are found only on small offshore islands around New Zealand. Our results show that Amblyomma sphenodonti has a more severely restricted geographic distribution than its host, as it was found on only eight of 28 islands (four out of 12 island groups) where tuatara still live. The prevalence of A. sphenodonti is likely to have been affected by low host density and fluctuations in host population size as tuatara populations became isolated on offshore islands. Analysis of A. sphenodonti cytochrome oxidase 1 (CO1) sequences indicated a lack of gene flow between islands, with fixed differences in CO1 sequences between islands, but almost no genetic diversity within island populations. A similar phylogenetic pattern to that observed in tuatara mtDNA was observed, indicating co-evolution of two species, at least since the Pleistocene. Phylogenetic analysis using 18S rRNA sequences suggest that A. sphenodonti is not closely related to other Amblyomma species, and that a separate genus for this species may be warranted. However, data from other ixodid ticks are required before the distinctiveness of A. sphenodonti can be confirmed and the phylogenetic relationships among ixodid ticks fully understood. [ABSTRACT FROM AUTHOR]