Nutritional and social ecology of the sable antelope in a Magaliesberg Nature Reserve

This study focused on how changes in food availability during the dry season, influenced various aspects of sable (Hippotragus niger niger) foraging and social ecology. The main purpose of this was to determine whether differences in their foraging ecology explained the reduction in population size compared to other more abundant herbivores (e.g. zebra, buffalos, hartebeest). Contrary to expectation, sable did not limit their foraging to woodlands, but also fed in open grasslands, provided these retained green grass during the dry season. Wetlands were key resource areas during the dry season, but sable did not limit their feeding to these bottomland areas. They also fed on hill slopes and upper plateaus that had been burnt. During the study, sable were attracted to burnt areas despite the reduced grass availability. My study highlights how these burnt areas were important in alleviating nutritional deficiencies during the dry season. At lower spatial levels, I looked at the factors that influenced the selection of feeding areas and plant species. Like other grazers, sable were attracted to green leaves but did not avoid brown leaves or stems. Grass species eaten were the same as those preferred by most domestic and wild grazers. Surprisingly, adult males stayed with the breeding herds despite their different activity budgets. Unlike most other African grazers, sub adult sable males did not form bachelor groups. Instead, they stayed within the breeding herds the whole time and had a similar activity budget to females. As adult males moved with the breeding herds, I was able to examine the costs and benefits involved with such a social structure. From this, I was able to relate my results to the bigger picture of factors influencing sexual segregation in ungulates. In conclusion, sable utilised a wide variety of habitat types and adjusted their foraging behaviour to accommodate different seasonal situations. I was unable to find anything in their feeding ecology that could explain the continued decline in population size. Therefore, I suggest that future research needs to focus on other potential causes such as a higher susceptibility to predation and disease as compared to more abundant herbivore species

Habitat selection in adult males of Alpine ibex, <i>Capra ibex ibex</i>

Habitat use and selection of 14 Alpine ibex males were studied in the Gran Paradiso National Park. Alpine meadows were always overused and positively selected, because this habitat constituted an important food resource for the ibex. Even if rocks (30%) and stone ravines (22%) were the most frequented habitats in the study area, their use was lower than their availability because they offered few trophic resources. Pastures were used only in spring when the ibexes were looking for those sites just free from snow and with fresh vegetation. Stone ravines, where the ibexes rested in the hottest days, were most used in summer. Rocks were most used in winter: rock-faces are the only sites where the risk of avalanches is low and where it is still possible to find snow-free patches. Larch woods were especially used in winter and spring when it was still possible to find snow-free patches. The home range sizes proved to be influenced by the amount of Alpine meadows and rocks

Rhinoceros from the Middle Stone Age in the Eastern and Western Cape of South Africa

In southern Africa, the Middle Stone Age (MSA), spanning more than 200,000 years, is a critical time period, in which Homo sapiens first appears. MSA sites located in the Eastern and Western Cape provinces of South Africa have yielded extensive faunal assemblages accumulated by anatomically modern humans. Many of these faunal assemblages include evidence of rhinoceros. To investigate how rhinoceros were potentially hunted/scavenged, we compare the representation of rhinoceros with that of large bovids and zebras in these faunal assemblages across seven sites in the region. All sites contain individual specimens of rhinoceros; however most faunal assemblages yielded only a few isolated specimens (201 specimens in total, representing 5% of the total sample). Similarly low representation was found for elephant and hippopotamus. In total, 60% of all the remains of rhinoceros accumulated during the MSA were found at a single site, Die Kelders. This indicates that people rarely brought back portions of rhinoceros carcasses containing bones to cave and shelter sites. The low frequency of rhinoceros findings suggests that people either did not regularly hunt or scavenge carcasses of these large ungulates, which are known for their aggressive behaviour; or, due to their large size inhibiting portability, they camped and feasted on rhino carcasses at sites where the animals were killed. In the latter scenario, meat containing a few bones could have been dried and brought to caves.publishedVersio

Resource selection in reintroduced lions and the influence of intergroup interactions

Optimal resource selection is crucial for maximising fitness and survival. Animals introduced to a new area need time to explore the environment, which could result in a time lag before optimal selection occurs. Furthermore, intra‐specific interactions (particularly in territorial species) also play a role in shaping resource selection patterns, with weaker individuals being displaced from optimal resources. We assessed within‐home range habitat selection of lions (Panthera leo ) introduced to a South African wildlife reserve, to examine changes in their resource selection patterns across 3 years from the time of introduction, and the effect of intra‐specific interactions on these selection patterns. After initial exploration, lions selected low altitudes and flat slopes that facilitate movement, high tree densities that provide cover and refuge, and areas close to water sources and flood plains that have high prey density. Responses to human disturbances differed between males and females, with males being more tolerant to high densities of roads and buildings. These patterns were however disrupted by deaths due to intergroup conflicts and by introductions of new individuals, with the dominant groups remaining within favourable resources and subordinate groups shifting to suboptimal resources. Our findings support the spatio‐temporal dynamic nature of habitat selection processes for reintroduced large carnivores and emphasize the role of intra‐specific interactions in influencing the landscape determinants of habitat selection.The Rufford Small Grants for Nature Conservation and The University of Hong Kong Postgraduate Research Travel Award.https://zslpublications.onlinelibrary.wiley.com/journal/14697998hj2020Mammal Research Institut

Migrating focal seizures and myoclonic status in ARV1-related encephalopathy

Objective: To report longitudinal clinical, EEG, and MRI findings in 2 sisters carrying compound heterozygous ARV1 mutations and exhibiting a peculiar form of developmental and epileptic encephalopathy (DEE). Neuropathologic features are also described in one of the sisters. Methods: Clinical course description, video-EEG polygraphic recordings, brain MRI, skin and muscle biopsies, whole-exome sequencing (WES), and brain neuropathology. Results: Since their first months of life, both girls exhibited severe axial hypotonia, visual inattention, dyskinetic movements, severe developmental delay, and slow background EEG activity. Intractable nonmotor seizures started in both at the eighth month of life, exhibiting the electroclinical characteristics of epilepsy of infancy with migrating focal seizures (EIMFS). In the second year of life, continuous epileptiform EEG activity of extremely high amplitude appeared in association with myoclonic status, leading to severely impaired alertness and responsiveness. Repeated brain MRI revealed progressive atrophic changes and severe hypomyelination. WES identified a compound heterozygous in the ARV1 gene [(p.Ser122Glnfs*7) and (p.Trp163*)] in one patient and was subsequently confirmed in the other. Both sisters died prematurely during respiratory infections. Postmortem neuropathologic examination of the brain, performed in one, revealed atrophic brain changes, mainly involving the cerebellum. Conclusions: This report confirms that biallelic ARV1 mutations cause a severe form of DEE and adds epilepsy with migrating focal seizures and myoclonic status to the spectrum of epilepsy phenotypes. Considering the potential role of human ARV1 in glycosylphosphatidylinositol (GPI) anchor biosynthesis, this severe syndrome can be assigned to the group of inherited GPI deficiency disorders, with which it shares remarkably similar clinical and neuroimaging features. ARV1 should be considered in the genetic screening of individuals with EIMFS

How free-ranging ungulates with differing water dependencies cope with seasonal variation in temperature and aridity

Large mammals respond to seasonal changes in temperature and precipitation by behavioural and physiological flexibility. These responses are likely to differ between species with differing water dependencies. We used biologgers to contrast the seasonal differences in activity patterns, microclimate selection, distance to potential water source and body temperature of the water-independent gemsbok (Oryx gazella gazella) and water-dependent blue wildebeest (Connochaetes taurinus), free-living in the arid Kalahari region of Botswana. Gemsbok were more active nocturnally during the hot seasons than in the cold-dry season, while wildebeest showed no seasonal difference in their nocturnal activity level. Both species similarly selected shaded microclimates during the heat of the day, particularly during the hot seasons. Wildebeest were further than 10 km from surface water 30% or more of the time, while gemsbok were frequently recorded &gt;20 km from potential water sources. In general, both species showed similar body temperature variation with high maximum 24-h body temperature when conditions were hot and low minimum 24-h body temperatures when conditions were dry, resulting in the largest amplitude of 24-h body temperature rhythm during the hot-dry period. Wildebeest thus coped almost as well as gemsbok with the fairly typical seasonal conditions that occurred during our study period. They do need to access surface water and may travel long distances to do so when local water sources become depleted during drought conditions. Thus, perennial water sources should be provided judiciously and only where essential

Contrasting capabilities of two ungulate species to cope with extremes of aridity

Southern Africa is expected to experience increased frequency and intensity of droughts through climate change, which will adversely affect mammalian herbivores. Using bio-loggers, we tested the expectation that wildebeest (Connochaetes taurinus), a grazer with high water-dependence, would be more sensitive to drought conditions than the arid-adapted gemsbok (Oryx gazella gazella). The study, conducted in the Kalahari, encompassed two hot-dry seasons with similar ambient temperatures but differing rainfall patterns during the preceding wet season. In the drier year both ungulates selected similar cooler microclimates, but wildebeest travelled larger distances than gemsbok, presumably in search of water. Body temperatures in both species reached lower daily minimums and higher daily maximums in the drier season but daily fluctuations were wider in wildebeest than in gemsbok. Lower daily minimum body temperatures displayed by wildebeest suggest that wildebeest were under greater nutritional stress than gemsbok. Moving large distances when water is scarce may have compromised the energy balance of the water dependent wildebeest, a trade-off likely to be exacerbated with future climate change.DATA AVAILABILITY : The data that support the findings of this study are available in AfriMove repository, www.afrimove.org.The National Research Foundation of South Africa, the Centre for African Ecology; and University of the Witwatersrand Faculty of Science Research Committee.https://www.nature.com/srepam2022Zoology and Entomolog

CDKL5 deficiency disorder: progressive brain atrophy may be part of the syndrome

The clinical phenotype of Cyclin-Dependent Kinase-Like 5 (CDKL5) deficiency disorder (CDD) has been delineated but neuroimaging features have not been systematically analyzed. We studied brain magnetic resonance imaging (MRI) scans in a cohort of CDD patients and reviewed age at seizure onset, seizure semiology, head circumference. Thirty-five brain MRI from 22 unrelated patients were included. The median age at study entry was 13.4 years. In 14/22 patients (85.7%), MRI in the first year of life was unremarkable in all but two. In 11/22, we performed MRI after 24 months of age (range 2.5-23 years). In 8 out of 11 (72.7%), MRI showed supratentorial atrophy and in six cerebellar atrophy. Quantitative analysis detected volumetric reduction of the whole brain (-17.7%, P-value = 0.014), including both white matter (-25.7%, P-value = 0.005) and cortical gray matter (-9.1%, P-value = 0.098), with a reduction of surface area (-18.0%, P-value = 0.032), mainly involving the temporal regions, correlated with the head circumference (&amp; rho; = 0.79, P-value = 0.109). Both the qualitative structural assessment and the quantitative analysis detected brain volume reduction involving the gray and white matter. These neuroimaging findings may be related to either progressive changes due to CDD pathogenesis, or to the extreme severity of epilepsy, or both. Larger prospective studies are needed to clarify the bases for the structural changes we observed

GWAS meta-analysis of over 29,000 people with epilepsy identifies 26 risk loci and subtype-specific genetic architecture

Epilepsy is a highly heritable disorder affecting over 50 million people worldwide, of which about one-third are resistant to current treatments. Here we report a multi-ancestry genome-wide association study including 29,944 cases, stratified into three broad categories and seven subtypes of epilepsy, and 52,538 controls. We identify 26 genome-wide significant loci, 19 of which are specific to genetic generalized epilepsy (GGE). We implicate 29 likely causal genes underlying these 26 loci. SNP-based heritability analyses show that common variants explain between 39.6% and 90% of genetic risk for GGE and its subtypes. Subtype analysis revealed markedly different genetic architectures between focal and generalized epilepsies. Gene-set analyses of GGE signals implicate synaptic processes in both excitatory and inhibitory neurons in the brain. Prioritized candidate genes overlap with monogenic epilepsy genes and with targets of current antiseizure medications. Finally, we leverage our results to identify alternate drugs with predicted efficacy if repurposed for epilepsy treatment

Genome-wide identification and phenotypic characterization of seizure-associated copy number variations in 741,075 individuals

Copy number variants (CNV) are established risk factors for neurodevelopmental disorders with seizures or epilepsy. With the hypothesis that seizure disorders share genetic risk factors, we pooled CNV data from 10,590 individuals with seizure disorders, 16,109 individuals with clinically validated epilepsy, and 492,324 population controls and identified 25 genome-wide significant loci, 22 of which are novel for seizure disorders, such as deletions at 1p36.33, 1q44, 2p21-p16.3, 3q29, 8p23.3-p23.2, 9p24.3, 10q26.3, 15q11.2, 15q12-q13.1, 16p12.2, 17q21.31, duplications at 2q13, 9q34.3, 16p13.3, 17q12, 19p13.3, 20q13.33, and reciprocal CNVs at 16p11.2, and 22q11.21. Using genetic data from additional 248,751 individuals with 23 neuropsychiatric phenotypes, we explored the pleiotropy of these 25 loci. Finally, in a subset of individuals with epilepsy and detailed clinical data available, we performed phenome-wide association analyses between individual CNVs and clinical annotations categorized through the Human Phenotype Ontology (HPO). For six CNVs, we identified 19 significant associations with specific HPO terms and generated, for all CNVs, phenotype signatures across 17 clinical categories relevant for epileptologists. This is the most comprehensive investigation of CNVs in epilepsy and related seizure disorders, with potential implications for clinical practice