Search

Although ovarian endocrine activity has been described in most members of the tribe Hippotragini, little is known about the reproductive endocrine correlates of the roan antelope (Hippotragus equinus), an endangered antelope species of southern Africa. This study characterised the endocrine pattern of the reproductive activity (oestrous cycle, pregnancy and post‐partum period) in the female roan antelope by monitoring faecal progestogen metabolite (fPM) concentrations and oestrogen metabolite (fEM) concentrations for cyclicity and observing reproductive behaviours. The study was carried out over the course of 12 months. At the beginning of this study, all 18 focal females (nulliparous, primiparous and multiparous) were monitored for cyclicity (for between 3 and 4 months). Following observed copulation, pregnancy in multiparous females (n = 10) was subsequently monitored until parturition and 21 days post‐partum. Individual faecal samples were collected three times per week during the presumed period of cyclicity, twice per week during pregnancy and daily for 21 days post‐partum. Mating births, courtship events, and copulations were recorded when observed. In eight of the 18 females monitored, the patterns of fPM and fEM concentrations indicated oestrous cycle lengths (n = 10) of approximately 30.8 ± 2.1 days. The determined lengths of luteal and follicular phases were approximately 15.8 ± 1.5 days and 14.6 ± 2.1 respectively. Pregnancy was marked by a pronounced increase in fPM concentrations until parturition, and lasted approximately 280.4 ± 4.8 days; whereas the intercalving period ranged between 306 and 380 days (n = 9; mean: 333.2 ± 7.4 days). Twenty‐one day after parturition, 78% of the focal females (n = 5) did not show a resumption of the ovarian activity. This study demonstrated that monitoring faecal reproductive hormone metabolite patterns is a valuable approach for estimating ovarian activity in roan antelope and may be used to assist respective conservation breeding programmes by improving management practices. [ABSTRACT FROM AUTHOR]

Cases of Theileria -associated mortality are rarely reported in African wild artiodactyls. Descriptions of lesions are limited, particularly in endangered hippotraginids. Here, we analyzed retrospectively the gross and histologic findings in 55 roan antelope (Hippotragus equinus) with fatal natural theileriosis. The most frequently recorded gross findings in 40 cases were widespread petechiae and ecchymoses (72.5%), probable anemia (67.5%), icterus (60%), splenomegaly (60%), hepatomegaly (52.5%), and pulmonary edema (50%). Histologic lesions in 34 cases were characterized by multi-organ infiltrates of parasitized and nonparasitized mononuclear leukocytes (MLs), and fewer multinucleate giant cells (MNGCs). Liver, lung, kidney, adrenal gland, and heart were most consistently infiltrated, followed by spleen and lymph nodes. Leukocytes were phenotyped in lung, liver, kidney, and heart specimens from 16 cases, using immunohistochemistry to detect CD20, CD3, myeloid/histiocyte antigen (MAC387), IBA-1, and CD204 surface receptors. A roan polyclonal anti- Theileria sp. (sable) antibody was applied to the same tissues to identify intraleukocytic parasite antigens. Similar proportions of intravascular and extravascular IBA-1-, CD204-, and MAC387-reactive putative monocyte-macrophages and fewer CD3-positive putative T-lymphocytes were identified in all organs, especially the lungs in infected roan. CD20-positive putative B-lymphocytes were significantly scarcer than in uninfected controls. Intraleukocytic Theileria parasites labeled consistently in affected tissues. Some parasitized and nonparasitized MLs and the MNGCs failed to label with selected leukocyte markers. Fatal theileriosis in roans may largely be the result of multi-organ monocyte-macrophage activation with associated tissue injury and overwhelming systemic inflammation. The identity of the parasitized leukocytes and characteristics of the lymphohistiocytic response require further clarification in roans. [ABSTRACT FROM AUTHOR]

A 2-y-old, intact male roan antelope ( Hippotragus equinus ) was submitted for routine postmortem investigation after a prolonged history of diarrhea and weight loss. The abomasal mucosa was diffusely thickened and corrugated. Abomasal gland hyperplasia was associated with abundant apical organisms consistent with Cryptosporidium spp. Genomic DNA was extracted from abomasal and intestinal contents and subjected to PCR using primers specific for the 18S rRNA gene of Cryptosporidium spp., followed by Sanger sequencing. The sequence was >99% homologous to Cryptosporidium andersoni. C. andersoni -associated proliferative abomasitis has not been reported previously in a captive hippotraginid, to our knowledge., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Aim: Phylogeographic studies on savanna ungulates have extensively evaluated genetic patterns mostly related to Pleistocene climatic oscillations. We address this subject through a comprehensive assessment across the pan‐African range of the roan antelope, assessing whether climatic oscillations or natural physical barriers play a predominant role in the evolutionary history of the species. We also address the spatial concordance of the genetic structure with the currently recognized subspecies. Location: Sub‐Saharan Africa. Taxon: Roan antelope (Hippotragus equinus). Methods: We genotyped 43 microsatellite loci and sequenced whole‐mitochondrial genomes for 131 individuals across the species' entire African range. We performed spatial analyses of genetic diversity for contemporary and historical samples and calculated overall patterns of genetic differentiation and structure for both marker types. We also estimated the timing of divergence events and demographic trends, correlating these with the species' biotic attributes as well as abiotic features shaping African savanna habitats. Results: Our analyses uncovered highly structured clusters and contact zones across the distribution of the roan antelope, including five nuclear groups and four mitochondrial lineages. The north‐west group had the highest level of intra‐group diversity as well as inter‐group divergence and represents the oldest vicariant event. The central and southern groups had the lowest intra‐group diversity with low divergence values separating them, suggesting a more recent ancestry for these groups. All population groups showed signals of demographic stability over time showed signals of demographic stability over a demographic decline during the Holocene. Main conclusions: The roan antelope exhibits significant population structure across its African range. This structure is largely associated with natural physical barriers, whereas contact zones could more easily be explained by climatic events. Based on estimates of genetic diversity, we propose a West African ancestry for this species with subsequent eastward and southern range expansions, as well as the persistence of stable population numbers within refugia. A general trend of population size decreases likely reflects Holocene extreme climatic events and increased human pressure. [ABSTRACT FROM AUTHOR]

Little information exists on the sexual behaviours of the roan antelope (Hippotragus equinus; É. Geoffroy Saint-Hilaire, 1803), a species listed vulnerable in southern Africa. To fill this gap, two adult males and 13 adult females from two captive breeding herds, at Lapalala Wilderness, South Africa, were observed three times per day from September 2017 to July 2018. Pre-categorised behaviours exhibited by males and females were recorded and their frequencies quantified. Fifteen pre-defined behaviours were recorded in males with precopulatory behaviours being the most recurrent. Overall, 181 courtships and 73 complete mounts (copulations) were recorded for the two mating periods observed; each mount lasted between 3 and 4 s. In females, eight pre-defined behaviours were observed and homosexual mounts were observed for the first time in females of this species and indeed within the Hippotragini tribe. Receptivity lasted for between 24 and 72 h, with prominent behaviours being copulation, flehmen and urination. Besides hiding, moving away or lying-out, non-receptive females fell on their metacarpal joints when approached by a male, a behaviour not yet reported in hippotragine species. This study showed that courtship is the most prominent component of male mating behaviour and that receptivity in females may vary between 1 and 3 days. [ABSTRACT FROM AUTHOR]

Roan antelope (Hippotragus equinus) is the second-largest member of the Hippotraginae (Bovidae), and is widely distributed across subSaharan mesic woodlands. Despite being listed as "Least Concern" across its African range, population numbers are decreasing with many regional Red List statuses varying between Endangered and Locally Extinct. Although the roan antelope has become an economically-important game species in Southern Africa, the vast majority of wild populations are found only in fragmented protected areas, which is of conservation concern. Genomic information is crucial in devising optimal management plans. To this end, we report here the first de novo assembly and annotation of the whole-genome sequence of a male roan antelope from a captive-breeding program. Additionally, we uncover single-nucleotide variants (SNVs) through re-sequencing of five wild individuals representing five of the six described subspecies. We used 10X Genomics Chromium chemistry to produce a draft genome of 2.56 Gb consisting of 16,880 scaffolds with N50= 8.42 Mb and a BUSCO completeness of 91.2%. The draft roan genome includes 1.1 Gbp (42.2%) repetitive sequences. De novo annotation identified 20,518 protein-coding genes. Genome synteny to the domestic cow showed an average identity of 92.7%. Re-sequencing of five wild individuals to an average sequencing depth of 9.8x resulted in the identification of a filtered set of 3.4x106 bi-allelic SNVs. The proportion of alternative homozygous SNVs for the individuals representing different subspecies, as well as differentiation as measured by PCA, were consistent with expected divergence from the reference genome and among samples. The roan antelope genome is a valuable resource for evolutionary and population genomic questions, as well as management and conservation actions. [ABSTRACT FROM AUTHOR]

Nutrient hotspots strongly attract mammalian herbivores in nutrient-poor habitats such as savanna systems. However, little is known about their seasonal importance for mammalian herbivore species, particularly grazers. In addition, no study has fully quantified the potential re-distribution of nutrients into the surroundings of these hotspots. We assessed nutrient hotspot (i.e., grazing lawns and termite mounds) use by herbivores in a Miombo ecosystem of the Issa valley, Tanzania, using dung counts, camera traps and stable isotope analyses over a one year period, from May 2016 to October 2017. We conducted dung counts along four transects each radiating away from ten termite mounds and six grazing lawns as well as in 16 control sites 100 m away from each nutrient hotspot. In addition, we sprayed grasses around five termite mounds with urea and traced the isotopic signature back in grazing herbivore dung. Grazer dung deposition was twice as high in hotspot areas vs control sites. A total of 32 camera stations recorded 244 wildlife encounters, with mammalian herbivores using hotspot areas four times more frequently compared to control plots. Stable isotope analyses highlighted that dung deposited by mammalian grazers around hotspots likely originated from grasses within or close to hotspot areas, indicating that grazers are responsible for maintaining nutrient stability of these hotspots. We, therefore, emphasize the importance of grazing mammal species for the long-term persistence of hotspots and, thus, their contribution to the maintenance of a heterogeneous landscape within the Miombo ecosystem.

Population viability analysis (PVA) was used to (1) establish causes of roan population decline for the past 30 years in Ruma National Park (RNP), the only park where wild roans remain in Kenya, and (2) predict the probability of roan persistence under existing and alternative management options. PVA was done using long-term data based on population dynamics, life history, climatic conditions, and expert knowledge. Poaching was identified as the main cause of roan decline in RNP. Several antipoaching and prioritized habitat management interventions to promote population recovery and sustainable conservation of roans are described. PVA predictions indicated that, without these interventions, the roan population cannot persist more than 3 decades. Furthermore, ensuring sustainable conservation of roans in RNP will boost tourism in Western Kenyan and thus alleviate poverty in this part of the country. Improved income from tourism will reduce the possible pressures from hunting and give greater incentives for local people to be actively engaged in roan conservation. [ABSTRACT FROM AUTHOR]

In West Africa, whether in forests or savannahs, most of the large mammal species have a scattered spatial distribution. Monitoring their population size represents a logistic, financial, theoretical challenge because counting of transects is not appropriate, unlike elsewhere in Africa. In this study, we (i) analyse the patterns of interannual (2006-2008) changes in population density of seven sympatric species of savannah herbivores in a protected area of Burkina Faso with two alternative methods: dung counts versus direct counts and (ii) quantify the economic costs for these two methods. The seven species of mammals we considered are the following: Hippotragus equinus, Alcelaphus busephalus, Sylvicapra grimmia, Tragelaphus scriptus, Ourebia ourebi, Kobus ellipsiprymnus and Phacochoerus africanus. A distance methodology was used to generate estimates with both methods. There were significant correlations between estimates of mammal density obtained using dung counts and direct counts, and an analysis of covariance revealed that the interannual trends in population densities were consistently detected with both methods. In addition, the dung count method costs 55% less. Thus, our study documents that dung counts can be used as a proxy of population size fluctuations for the seven studied species, offering a methodological alternative that is much less expensive, less sophisticated in terms of equipment compared to other methods and that can be performed by field staff with moderate professional qualification. We suggest that standardized campaigns of dung count surveys may be applied to all protected areas and savannah in Burkina Faso, West Africa, in order to improve evidence-based, large-scale conservation and management planning in the region. [ABSTRACT FROM AUTHOR]

The roan antelope H ippotragus equinus, Africa's second largest antelope species, is widely distributed throughout Africa. Many populations are isolated, occur at low densities, and are declining. The species' interactions with and adaptations to the diverse environmental conditions throughout its geographic range remain largely unknown. Most studies have taken place in southern Africa, near the range limit for the species; few studies have been conducted on the historically large Central and West African populations., We reviewed available published and accessible unpublished data related to the ecology of roan antelope. We aim to: 1) review available taxonomic, abundance, distribution, and population trend data; 2) describe the threats faced by the roan antelope, and establish whether sufficient data exist to describe its ecological requirements; and 3) highlight the relevance of conserving this species throughout Africa and suggest where research on survival requirements should be focussed., Roan antelope populations throughout Africa are declining due to natural and anthropogenic threats. Methodological irregularities result in uncertainty and non-comparable population data between studies. Large gaps exist in our knowledge of roan antelope diet and regional movements. Information on the population genetics of roan antelope is needed in order to assess the connectedness of different populations., Data deficiency severely impedes our ability to employ powerful analytical methods aimed at understanding and predicting population persistence and viability, and to model envisaged threats from impending climate change. A unified approach to fundamental ecological research is required to inform the conservation and management of large rare mammalian ungulates such as the roan antelope in Africa. [ABSTRACT FROM AUTHOR]

Poaching with snares has been identified as the main cause of decline of the endemic roan antelope Hippotragus equinuslangheldi in Ruma National Park, Kenya, from > 200 in 1979 to 37 in 2009. However, the spatial snaring patterns in the Park are not clearly understood. The focus of our study was to map the spatial distribution of snares in the Park and to identify the factors influencing this distribution, to develop effective methods of wildlife protection. Using data collected from 56 sample plots during 2006–2008, coupled with geographical information system techniques, we investigated the association between the occurrence of snares and the distribution of geographical features (slope, elevation), infrastructure (roads, fences), essential resources for wildlife (water, salt licks, forage), roan locations and wildlife density. Ripley's L function for assessing complete spatial randomness indicated that snares occurred in clumps (hotspots) up to 4 km apart. Negative binomial regression indicated that these hotspots occurred (1) near water resources, salt licks and the Park boundary, (2) far from roan locations and Park roads, (3) in areas with low gradients and low wildlife density, and (4) in areas with burned vegetation. We recommend concentrating routine security patrol efforts and resources on snare hotspots to reduce snaring and to protect the roan antelope and other threatened wildlife. [ABSTRACT FROM AUTHOR]

• Faecal glucocorticoid metabolites (fGCM) can be reliably quantified in roan antelope. • Male roan antelope showed high fGCM levels during active reproductive periods. • fGCM levels increase prior to copulation in male roan. • fGCM levels increased during pregnancy and peaked at parturition in female roan antelope. • Captive roan antelope show higher fGCM levels in the dry season. Populations of roan antelope (Hippotragus equinus) in southern Africa have experienced a drastic decline over the past few decades and this situation has led to the development of intensive breeding programmes to support conservation efforts. However, little is known about related welfare aspects, including stress-related physiological biomarkers. The present study set out to establish a non-invasive method to monitor faecal glucocorticoid metabolite (fGCM) concentrations as a measure of stress and determine fGCM concentrations in relation to male reproductive activity and female reproductive status in the roan antelope. An adrenocorticotrophic hormone challenge was performed using two adult roan antelope (one male and one female) at Lapalala Wilderness Nature Reserve, South Africa, to determine the suitability of five enzyme immunoassays (EIA) for monitoring adrenocortical function in roan antelope. An 11-oxoaetiocholanolone I EIA detecting 11,17 dioxoandrostanes performed best showing 17–20 folds increases in fGCM concentrations after 12 h-17 h post-injection. The identified EIA was then used to monitor fGCM concentrations during active and non-active reproductive periods in males (n = 3), and during periods of cyclicity, gestation, and postpartum in females (n = 10). Males showed an overall 80% increase in fGCM concentrations when reproductively active and females showed a progressively significant increase in fGCM levels throughout pregnancy, with overall fGCM concentrations being 1.5 to 2.6-fold higher than the respective fGCM concentrations during periods of postpartum and cyclicity, respectively. Furthermore, fGCM concentrations remained above baseline for up to 21 days post-partum. A correlation between ecological parameters (rainfall and temperature) and fGCM concentrations revealed elevated fGCM concentrations during the dry season for males, but not females. The non-invasive method validated in this study provides a valuable tool to quantify stress-related biomarkers in roan antelope, and findings can be used to support management decisions in conservation breeding facilities. [ABSTRACT FROM AUTHOR]

The roan antelope is locally endangered in Kenya with <50 individuals remaining in Ruma National Park ( RNP). An understanding of the habitat requirements is essential to formulate habitat management strategies for species recovery. This study identifies habitat and management features affecting roan distribution in different seasons using information-theoretic and multimodel inference ( MMI) techniques. MMI averaged models were coupled with GIS data to develop habitat suitability maps. Results showed that roan habitat suitability is determined by different factors in different seasons but overall habitat was more important than management. Best predictors of roan incidence were wooded grassland, open grassland and water points. Water was more significant in the dry season whilst vegetation burned status, slope, soil type, distances to snares, park fence and security gates were important predictors at other seasons. Receiver operating characteristic ( ROC) plots confirmed that the models fitted well to the data ( AUC>0.9). Sustainable conservation of roans in RNP can be achieved via long-term habitat management including prescribed burning and construction of more water points and short-term urgent solutions to key management issues, especially control of poaching. [ABSTRACT FROM AUTHOR]

Four hand-reared, naïve roan antelope, 4 months of age, were exposed to naturally infected pasture on a game farm in Mpumalanga Province, South Africa, where roan are known to die from theileriosis. Various clinical parameters were recorded during this period. The predominant ticks parasitising these animals at the time (January to February), were Rhipicephalus appendiculatus and Rhipicephalus evertsi evertsi adults. After a period of 5 weeks the animals developed signs of clinical theileriosis and were treated with buparvaquone to prevent mortality. Primary hyperplasia of the local draining lymph nodes (Lnn. anorectales) near the feeding site of adult R. evertsi evertsi indicated possible transmission of Theileria sp. (sable) by this tick species. After recovery from theileriosis, these animals were confirmed carriers of Theileria sp. (sable) by PCR (polymerase chain reaction) and DNA probe analysis. Laboratory-bred larvae and nymphs of R. evertsi evertsi and R. appendiculatus respectively, were fed on the ears of these roan antelope. Salivary glands from moulted and prefed adult ticks of each species were dissected and stained for Theileria spp., and the PCR and DNA probe applied to a representative batch of dissected glands. R. appendiculatus adults collected from grass in infected camps were also dissected after prefeeding them on rabbits. Salivary glands of both tick species showed infected acini on staining and were also positive for Theileria sp. (sable) only, on multiprotozoal PCR-screening analysis. There was no statistical significant difference between the infection rate and the intensity of infection between the two tick species. R. appendiculatus ticks collected from grass were also PCR-positive for Theileria sp. (sable).

Summary [ABSTRACT FROM AUTHOR]

Abstract: Blood specimens were received from five cases in which young adult giraffe, from different geographic origins in South Africa, showed sudden onset of disease and subsequently died. Additional specimens from two translocated giraffe, as well as one specimen from a roan antelope, were also included in the study. Blood slides from some of these animals showed the presence of piroplasms. DNA was extracted; the V4 hypervariable region of the 18S rRNA gene amplified and analyzed using the Reverse Line Blot (RLB) hybridization assay. PCR products failed to hybridize with any of the Babesia or Theileria species-specific probes, and only hybridized with the Babesia/Theileria genus-specific probe suggesting the presence of a novel species or variant of a species. Full-length 18S rDNA was amplified, cloned and the recombinants were sequenced. 18S rRNA gene sequence similarity analysis revealed the presence of novel piroplasm species in both healthy giraffe and a roan antelope and clinically sick or dead giraffe. Phylogenetic analysis grouped five of these organisms in the Babesia sensu stricto clade and three in the Theileria sensu stricto clade. Although parasites were observed in blood smears, there is no direct evidence that piroplasmosis caused the death of five giraffe, although it certainly seems to be likely. [Copyright &y& Elsevier]

Abstract: A major focus in population ecology is understanding factors that limit rare species. We used stable isotope approaches to diet to determine whether remaining rare antelope populations in Kruger National Park (KNP), South Africa experience i) nutritional stress; ii) competition with sympatric bulk grazers; iii) reduced habitat heterogeneity. Rare species consumed near-pure C4 grass-based diets throughout the seasonal cycle, in contrast to field observations that reported significant levels of C3 consumption (browse) by these taxa. This finding, coupled with low faecal %N at the height of the dry season, may indicate nutritional stress, but recent isotopic studies of the same species elsewhere in Africa suggest that field observations overestimated levels of browse consumption. We find little evidence for diet niche overlap between rare antelope with bulk grazing species. This partitioning of resources (interpreted mainly as tall- versus short-grass grazing, respectively), is consistent with reported differences in observed diet, and comparative oral morphology. Last, we find less seasonal diet variations amongst bulk grazers feeding in rare antelope habitats compared with other landscapes. We propose that loss of functional heterogeneity, apparently brought about by high densities of artificial waterholes, limits recovery of diet- and habitat-selective rare antelope populations in KNP. [Copyright &y& Elsevier]

Studies investigating animal movement and habitat use are essential for wildlife management and conservation. Northern Botswana represents some of the least modified landscapes in Africa. Studying the seasonal habitat use of herbivores in these landscapes provides important baseline information with which to compare the behavioural responses of similar species occurring in anthropogenically modified landscapes. We report on the home range extent and habitat use of roan antelope (Hippotragus equinus) in a region of northern Botswana unaffected by artificial water and fences. We deployed Global Positioning System (GPS) collars on individuals in four roan antelope herds in northern Botswana, three herds in the drier northern section of Botswana and one herd in the wetter Okavango Delta. Herds in the drier northern section occupied larger home ranges (>50 km2) than did herds in the wetter Okavango Delta (<50 km2). All herds preferred specific core areas (all smaller than 20 km2) within their home ranges. All herds had similar location and size of home range between the wet and dry season (non-migratory). All herds occurred in back-country sandveld areas dominated by either Kalahari apple-leaf (Philenoptera nelsii) or silver cluster-leaf (Terminalia sericea) woodlands with low densities of competitors and predators. In Botswana, the long-term persistence of free-roaming roan antelope herds likely depends on the preservation of these unmodified back-country habitats away from permanent water. [Display omitted] • First study to investigate the home ranges and habitat use of roan antelope in northern Botswana. • Study area is relatively unhindered by human intervention (i.e. no water provision, fences), providing a useful model system for understanding natural roan antelope habitat use through seasons. • Importance of 'back-country' habitats away from permanent water is highlighted for persistence of the species. • Management actions for conserving heterogeneity should not ignore 'marginal' habitats or those reflecting low abundance as these may be critical for maintaining rare species. [ABSTRACT FROM AUTHOR]

The use of landscape zones and grass species by roan antelope, a species threatened with local extirpation within South Africa's Kruger National Park, were investigated. Plant-based observations of grazing were made within a 300 ha enclosure in the roan range, where 40 roan antelope were confined at high density in the absence of other grazers. The study spanned the dry seasons of two years, one with average rainfall and one with low rainfall. We recorded changes in the extent of grazing of different grass species, height differences between grazed and ungrazed tillers and intensity of cropping per tuft. In the average year, the grazing pressure in the bottomland grassland was twice that in the upland savanna, with two tall grass species bearing the brunt of the grazing through the dry season. Two highly palatable upland grasses were also extensively grazed by the mid dry season. In the dry year, the extent of grazing in the upland exceeded that in the bottomland, and several upland grass species little used the previous year became heavily grazed. Roan antelope appeared to be separated ecologically from more common grazers by their selective use of tall grasses growing in the drainage line grassland during the critical dry season months. However, their grazing expansion into the upland savanna during the dry year potentially brought them into competition with these grazers. Nevertheless, their population performance did not suffer despite the high-density conditions. Heightened predation pressure following an influx of these grazers, rather than resource limitation, appeared to be primarily responsible for the drastic decline of this species in the park. [ABSTRACT FROM AUTHOR]

Summary: Neonatal, poikilocytic anaemia in some members of the Hippotragini has previously been documented but not fully investigated. This study was undertaken to describe the erythrocyte morphology of roan antelopes (Hippotragus equinus) during the first 4 weeks after birth and to identify aspects of haemoglobin (Hb) production that might be implicated in this syndrome. Twenty-nine roan antelope calves were sampled on, or close to, 1, 7, 14 and 28 days after birth. Erythrocyte morphology was characterized, and microhaematocrit values and Hb parameters determined, for each sampling occasion. Findings indicated a significant change in erythrocyte morphology during the neonatal period and two haemoglobin types, fetal and adult, were identified. The perinatal onset of adult Hb synthesis was delayed relative to the termination of fetal Hb production, resulting in the observed anaemia. Haemoglobin concentration and erythrocyte morphology were significantly correlated. These findings suggest an intimate relationship between Hb synthesis and the observed poikilocytosis. An imbalance in the synthesis of the α- and ß-globin chains of Hb (a thalassaemia) may prove to be the underlying pathophysiology of this syndrome. [Copyright &y& Elsevier]

Effective management of grazers requires understanding of the mechanisms influencing population declines. Roan antelope, a specialist grazer, has declined in population numbers within Kruger National Park, South Africa. The most widely accepted hypothesis is that habitat deterioration throughout the entire northern plains landscape is responsible for declines in this species. Observations suggest, however, that on the northern plains of Kruger National Park, roan antelope grazes at the boundary between ephemeral wetland and the savanna matrix. The boundary is characterized by nutrient-rich soil and forage, and thus attracts grazing from both generalist and specialist species. We hypothesize that competition for resources at this ecotone, and not at other places in the landscape, is responsible for the observed declines in roan antelope. Changing management strategies to be more cognizant of patchiness and savanna heterogeneity, i.e. more spatially informed, will improve the likelihood that management will result in increasing roan population numbers. [ABSTRACT FROM AUTHOR]

The roan antelope ( Hippotragus equinus) is the second largest African antelope, distributed throughout the continent in sub-Saharan savannah habitat. Mitochondrial DNA (mtDNA) control region sequencing (401 bp, n = 137) and microsatellite genotyping (eight loci, n = 137) were used to quantify the genetic variability within and among 18 populations of this species. The within-population diversity was low to moderate with an average mtDNA nucleotide diversity of 1.9% and average expected heterozygosity with the microsatellites of 46%, but significant differences were found among populations with both the mtDNA and microsatellite data. Different levels of genetic resolution were found using the two marker sets, but both lent strong support for the separation of West African populations (samples from Benin, Senegal and Ghana) from the remainder of the populations studied across the African continent. Mismatch distribution analyses revealed possible past refugia for roan in the west and east of Africa. The West African populations could be recognized together as an evolutionarily significant unit (ESU), referable to the subspecies H. e. koba. Samples from the rest of the continent constituted a geographically more diverse assemblage with genetic associations not strictly corresponding to the other recognized subspecies. [ABSTRACT FROM AUTHOR]

The article focuses on the feeding behavior of roan antelope involving sausage trees in Africa. It mentions that Hippotragus equinus is a savanna antelope found in Africa, and considered as one of the largest species of antelope. It notes that Kigelia is a genus of flowering plants in the family Bignoniaceae.

The article presents information on a research study to analyze the habitat structure of roan antelopes in Kainji Lake National Park in Nigeria. Roan antelopes are primarily grazers. The study has revealed that the common woody plants in the roan antelope habitat are acacia hockii, terminilia glaucescens, vitellaria paradoxa etc. and plant composition of the habitat also confirms that these animals prefer lightly wooded savanna woodland.