The composition of mixed-species foraging flocks of birds in Kruger National Park, South Africa

Areas within regional landscapes that make a disproportionate contribution to supporting large herbivore populations have been interpreted as key resource areas, hotspots, buffers, stepping stones or serving other functional roles. We investigated the role that the restricted extent of habitat types exploited at different stages of the seasonal cycle might play in limiting the abundance of a blue wildebeest subpopulation in the Kruger National Park, South Africa. GPS collars enabled the space use patterns of the animals to be related to available habitat types, and faecal nutrient concentrations to be related to the habitats exploited at that time. Wildebeest herds occupied primarily grazing lawn grasslands associated with gabbro uplands or sodic lowlands through the wet season into the early dry season. During the late dry season, they switched to seep‐zone grasslands in mid slope regions of granitic landscapes. Use of recently burned areas enhanced forage quality at the beginning of the wet season. The seasonal habitat shifts enabled wildebeest to obtain adequate nitrogen, phosphorus and sodium throughout the year. Lawn and seep‐zone grasslands combined constituted 10% of the available area. Grazing lawns, which encompassed only ˜ 3% of the study area, appeared to be the primary limitation on the abundance of wildebeest. However, the greater security from predation provided by the open vegetation cover in the grazing lawns is not easily disentangled from the resource benefits that they yield. Nevertheless, findings indicate how local abundance can be restricted by the extent of portions of the landscape providing crucial benefits during particular phases of the seasonal cycle. Hence the key resources concept needs to be expanded to accommodate the functionally distinct contributions made by different habitats towards supporting local herbivore populations.

Roan antelope are distributed mainly in regions characterized by infertile soils, offering food of low quality. We hypothesized that roan may select localities with higher soil nutrient levels and/or grass swards with more favourable properties in terms of food abundance or quality than generally available in those regions. Roan antelope were observed in a savanna region in South Africa where soils of widely varying nutrient status occurred. Roan favoured open grassland over wooded savanna areas. During the wet season, roan preferred sites with felsite‐derived soil of intermediate soil nutrient status. Grasslands growing on nutrient enriched alluvial soils were preferred outside of the early wet season, although most of the favourable sward characteristics were present in other landscape units. Food quantity, rather than quality appeared to attract roan to foraging sites in the late wet and early dry seasons. Food quality appeared more important in the early wet and late dry seasons. The higher degree of clustering of leafy material within foraging swards seemed to be an additional discriminating factor. The factors governing the selection of foraging sites by roan did not seem notably different from those influencing other species of grazing ruminant, but roan nevertheless seemed tolerant of stemmy grasslands growing on nutrient richer substrates.

Functional heterogeneity of habitats and dry season forage variability in an Okavango Delta landscape, northern Botswana

The consequences of predation for prey population dynamics depend on the extent to which this mortality is predisposed by malnutrition or senescence, or additive in the sense that animals that would otherwise not have died at that time were killed. In places lacking effective predators, few adult ungulates die during the summer or wet season months when food is plentifully available. Hence the seasonal distribution of predator kills as well as the age and sex classes of the prey indicates the extent to which malnutrition contributes to mortality as well as other influences on vulnerability. Using records of animal deaths assembled over 35 years in South Africa's Kruger National Park, these patterns were investigated for 12 ungulate species forming the prey of lions, and for three other large predators with respect to one prey species. Buffalo, kudu and giraffe were more strongly represented in kills made during the late dry season, while wildebeest and zebra made relatively greater contributions during the wet season. Impala, waterbuck, warthog and rarer antelope species became more prominent in kills during transitional periods between seasons. Five prey species showed an elevation in representation of males in lion kills during the mating season, as well as impala for all predator species. Females were more prominently represented in kills during the time of late gestation and parturition for three prey species. Hence reproductive activities as well as changing vegetation cover and food resources affected vulnerability to predation. Shifts in susceptibility to predation over the seasonal cycle corresponded with rainfall‐related variation in the annual representation of these ungulate species in lion kills. The availability of vulnerable prey species, age and sex classes at different stages of the seasonal cycle helps maintain a high abundance of lions. These factors contribute to the strong additive impact that predation has had on the abundance of some of these ungulate populations.

A trapping study of five mammal species in wet sclerophyll forest adjacent to rain forest in the Australian Wet Tropics was used to examine the seasonal diversity, abundance and dung-specificity of dung beetles associated with mammal dung. A total of 542 dung beetles from 11 species within three genera was recovered from beneath the traps of 1104 mammal captures. The diversity of beetles associated with the dung of the northern bettong (Bettongia tropica), a mycophagous marsupial, differed significantly from the diversity predicted by a null model. Numbers of beetles varied significantly with type of dung, indicating preference by beetles. Beetle numbers were related positively to a 1-mo lag in monthly mean minimum temperature and less strongly to maximum temperature and rainfall. Significantly more beetles per mammal capture were detected in the wet season than in the dry season. Dung beetles showed a strong preference for either the Eucalyptus woodland (six species) or the adjacent Allocasuarina forest (four species), with only one species occurring in both habitat types. Beetle species from the Eucalyptus woodland were typically only detected in the late wet and early dry seasons, while species in the wetter Allocasuarina forest were generally collected during the late dry and early wet seasons. A significant ‘checkerboard’ species effect was detected in both time and space in both habitat types, suggesting that competition for dung was strong.

The dietary preference of cattle grazing Stylosanthes-based pastures in the seasonally dry tropics of North Queensland was studied using faecal carbon ratios (S13C) to determine grass-legume proportions. Estimates were made at monthly intervals for several years in 1 experiment to determine the effect of year, season and botanical composition on dietary stylo proportions. In another experiment, the effect of stylo cultivars (Verano and Seca) on dietary preference was monitored for 17 months. Where pastures provided ample opportunity for selection, cattle showed a strong preference for grass in the early wet season and in the late dry season. The proportion of stylo in the diet increased during the wet season and reached peak proportions (as high as 80%) in the late wet season or early dry season. Dietary stylo proportions decreased as pastures dried off and as the stylo shed leaf or became more stemmy. The length of the wet season and the amount and distribution of rainfall had a major influence on the seasonal pattern of diet selection. Stylo rarely fell below 20% in the diet. On an annual basis, stylo accounted for about 45% of the diet which was appreciably higher than the proportion of stylo in the pasture. Dietary stylo proportions were higher on Seca-based pasture than on Verano-based pasture. The avoidance of stylo in the early wet season was less pronounced with Seca compared with Verano. Later in the season Seca was the dominant dietary component for a much longer period than Verano. The effect of botanical composition on dietary grass-legume proportions varied between and within years. Correlations between grass-legume proportions in the pasture and in the diet were highest in the late dry season and early wet season when preference for grass was strongest. At the end of the wet season when cattle preferred stylo, dietary stylo was not related to pasture stylo content except in a drought year. Averaged over the full year, dietary stylo content was significantly correlated with pasture stylo content in all years and the correlation was highest in a drought year when there was a high level of utilisation and less opportunity for selection. A simple model relating dietary stylo to pasture stylo was developed and is discussed.

The sexual cycles of two genera of frugivorous rain-forest pigeons, Ducula and Ptilinopus, and two ground-feeding pigeons of the open woodland, Geopelia humeralis and G. striata, have been studied at latitude 9D 29'S. in New Guinea. In P, iozonus, P. magnificus, G. humevalis and G. striata some males were sexually active and some females had enlarged follicles in each month of the year and so some individuals, at all times, were capable of breeding; there was an indication that this situation was general in the two genera. In the rain-forest species more birds had enlarged gonads in the late dry season and wet season than at other times. Both sexes of G. stviata had peak gonad size in the late wet and early dry seasons; G. humevalis maintained peak activity throughout the dry season; both species had small gonads in the late dry season. The cycles of gonad size of fruit pigeons and ground-feeding pigeons corresponded to the probable cycle of food abundance in the two habitats. There was no evidence of an effect of photoperiod in Geopelia but it could not be excluded in males of Ptilinopus.

Although wild chimpanzees are not seasonal breeders, there are seasonal effects on several aspects of chimpanzee reproduction. I examined the seasonal incidence of anogenital swelling in cyclic, pregnant, and acyclic female chimpanzees in Gombe National Park, May 1975–April 1992, and surveyed important reproductive events to determine whether there is a seasonal effect. I analyzed data by season (wet vs. dry) and seasonal quarter;early dry season = May–July;late dry = August–October;early wet = November–January;late wet = February–April. When data for the 17 years are combined, the percentage of females in each reproductive state remains consistent throughout the year. In a given month, 30–35% of subjects were in the cyclic category, 11–15% were pregnant, and 54–61% were acyclic. Cyclic females showed full swelling more often during the late dry season. Pregnant females exhibited anogenital swelling more often during the late dry and early wet seasons. Acyclic females also exhibited a seasonal effect with more anogenital swelling during the late dry season. There is no seasonal difference in frequency of live births (dry, 20;wet, 23). However, the timing of conception showed a seasonal effect (dry, 32;wet, 16). Consistent with earlier reports, the onset of postpartum cycles is highly seasonal;30 occurred during dry season, 9 during wet season. The occurrence of first full swellings for young females is also concentrated in the late dry season. It appears that the dry season is a time of great change for Gombe chimpanzee reproductive physiology. Previous studies indicated that seasonal changes in food availability play a role in increasing group size during the dry season and social contact between females can enhance cyclicity. Accordingly, I suggest that seasonal changes in diet may play a role, either directly (food content) or indirectly (social contact), to alter reproductive physiology.

Elephant- and human-induced changes to dung beetle (Coleoptera: Scarabaeidae) assemblages in the Maputaland Centre of Endemism

Hybridization between domestic and wild animals is a major concern for biodiversity conservation, and as habitats become increasingly fragmented, conserving biodiversity at all levels, including genetic, becomes increasingly important. Except for tropical forests and true deserts, African wildcats occur across the African continent; however, almost no work has been carried out to assess its genetic status and extent of hybridization with domestic cats. For example, in South Africa it has been argued that the long-term viability of maintaining pure wildcat populations lies in large protected areas only, isolated from human populations. Two of the largest protected areas in Africa, the Kgalagadi Transfrontier and Kruger National Parks, as well as the size of South Africa and range of landscape uses, provide a model situation to assess how habitat fragmentation and heterogeneity influences the genetic purity of African wildcats. Using population genetic and home range data, we examined the genetic purity of African wildcats and their suspected hybrids across South Africa, including areas within and outside of protected areas. Overall, we found African wildcat populations to be genetically relatively pure, but instances of hybridization and a significant relationship between the genetic distinctiveness (purity) of wildcats and human population pressure were evident. The genetically purest African wildcats were found in the Kgalagadi Transfrontier Park, while samples from around Kruger National Park showed cause for concern, especially combined with the substantial human population density along the park's boundary. While African wildcat populations in South Africa generally appear to be genetically pure, with low levels of hybridization, our genetic data do suggest that protected areas may play an important role in maintaining genetic purity by reducing the likelihood of contact with domestic cats. We suggest that approaches such as corridors between protected areas are unlikely to remain effective for wildcat conservation, as the proximity to human settlements around these areas is projected to increase the wild/domestic animal interface. Thus, large, isolated protected areas will become increasingly important for wildcat conservation and efforts need to be made to prevent introduction of domestic cats into these areas.

IntroductionSub-Saharan Africa has the largest number of people with HIV, one of the most severe burdens of adverse birth outcomes globally and particular vulnerability to climate change. We examined associations...

The study examined diversity and density of small mammal species with different seasons and habitats in Federal University Gashua, Yobe State, North-East, Nigeria. The university environment was divided in to four (4) habitat types, namely; University residential area (URA), Acacia woodlot (AWL), Lake Area (LA) and Farm Land (LF) were used for the study. Small Mammal species survey was carried out for the period of six (6) months from August to October, 2022 (wet season) and January, to March, 2023 (dry season). Capture Mark–Recapture (CMR) and indirect observations methods were adopted; Survey was conducted using spring door traps of different sizes set at the habitat types during late evening hours 6:00 pm and checked in the morning hours from 6:00-8:30am for four (4) days per week with each habitat types being visited one day per week, making total of (96) man-days. Each habitat type was visited twice a day (morning and evening) which gave a total of (65;60) trapping night in both wet and dry seasons, the number decreased to 60 trapping night in the dry season was due to the wearing a way of vegetation cover. (32) Visits per habitat types and one (1) night survey per month. A total of ten (10) species of small mammals belonging to ten (10) families and seven (7) orders were recorded in the study. African Hedgehog Atelerix albiventris and White toothed shrew Crocidura flavescens were the most occurring species across The findings of the study shows that the overall diversity index was (1.692), where Four-toed hedgehog Atelerix albiventris had the highest species diversity90.363) and estimated population density of (64.44) followed by Giant pouched rat Cricetomys gambianus with (0.277; 0.018) respectively, Cape hare Lepus capensis and Mongoose Herpestes ichneumon who’s having the lowest diversity of (0.017) with (0. 564) density each in the study area. The month of February has higher number of captured percentage with (24%) in dry season, followed by October with (19%) in the wet season, the lowest capture percentage occurred with August (14%) in the wet season. University Residential Area had more number of individual species having (37.82 %), while Farm land had the least captured percentage of(16.85%).The trap success in both wet season and dry season’s period were (33.04%; 21.67%)respectively. Habitat alteration and destruction due to ongoing constructions project, mainly for university deployment might have accounted for small mammal species low diversity and density in Federal University Gashua.

Factors affecting age at first lambing in Yankasa ewes.

Information on the breeding biology of the White-headed Vulture Trigonoceps occipitalis is limited and published data are few. Within the Kruger National Park in north-east South Africa there is a regionally important population of about 60 White-headed Vulture pairs, of which 22 pairs were monitored for five years between 2008 and 2012 to determine key aspects of their breeding biology. Across 73 pair/years the mean productivity of 55 breeding attempts was 0.69 chicks per pair. Median egg-laying date across all of the Kruger National Park was 27 June, but northern nests were approximately 30 d later than southern nests. Mean (±SD) nearest-neighbour distance was 9 976 ± 7 965 m and inter-nest distances ranged from 1 400 m to more than 20 km, but this did not differ significantly between habitat types. Breeding productivity did not differ significantly between habitat types. The results presented here are the first for this species in Kruger National Park and provide details against which future comparisons can be made.

Protected areas are central to the conservation of biodiversity across the globe. However, their performance, especially in relation to highly mobile species, is largely dependent on the socio-ecological characteristics of the landscape that surrounds them. Here, we assess the patterns of avian scavenger distribution, including both obligate (i.e., vultures) and facultative (corvids and other raptors) scavenger species, inside and outside of protected areas. We contrast the situation between an African area, which has protected areas surrounded by mostly subsistence stockbreeding (KwaZulu-Natal Province, South Africa) and a European area, which has protected areas surrounded by commercial farming (Ebro Valley, Spain). We found large differences between the two areas. In the South African area, the richness and abundance of vultures, but not of facultative scavengers, were higher inside than outside of protected areas; as a result, the richness and abundance of vultures were negatively related to the distance to the nearest protected area in South Africa. In contrast, the richness and abundance of vultures in the Spanish area were similar inside and outside of protected areas. We obtained similar results when focusing solely on presence and abundance of Gyps vultures. The contrasting effects of protected areas in the distribution of avian scavengers, especially vultures, in the studied areas may be due to differences in agro-systems and socio-economical models that lead to differential availability of ungulate carcasses. We suggest that carrion shortage in the subsistence farming systems in the South African area, whereby domestic livestock carcasses are generally used by householders and thus rarely become available to vultures, should be considered alongside poisoning prevention to help conserve African vulture populations.