Baobabs and elephants in Kruger National Park: nowhere to hide

Baobab size class distributions were surveyed in the Limpopo National Park (LNP), Mozambique, and the Kruger National Park (KNP), South Africa. There are very few elephants in the LNP and the baobab population there had a reverse J-shaped size class distribution with many small baobabs. In contrast, the elephant-impacted baobab population of KNP displayed a mono-modal size-class distribution, with a lack in recruitment. Within KNP, elephant impact (percentage bark stripped up to the height of 3 m) decreased with increasing rockiness and slope steepness. We interpret this to suggest that steep rocky slopes are inaccessible to elephants and therefore these sites may act as a refuge for baobabs. In such inaccessible areas, the baobab population has a similar size-class distribution to that of the populations in the LNP. However, these baobab refugia are restricted in the northern KNP landscape and are therefore probably not large enough to sustain a viable baobab population.     

Ecological drivers of female lion (Panthera leo) reproduction in the Kruger National Park

The role of social cues in the reproduction of social mammals, particularly carnivores, has been thoroughly studied and documented in literature. However, environmental cues such as resources of water, food, and shelter have been identified to a lesser extent. Pregnant lions (Panthera leo) are notoriously secretive during the final stages of pregnancy and postpartum. Behavioral indicators depicted by movement patterns obtained by remote detection of collared female lions in the Kruger National Park were necessary for the monitoring of birth timing. Over the study period, eight plus a potential three parturition incidences of collared females were recorded. Of the variables measured (step length, range size, duration, prey biomass, and rainfall), range size during the month of parturition was the most indicative movement pattern of a successful birth. By backdating the potential birth month of the litters, date of conception was calculated and our results revealed a correlation between the birthing peaks of preferred prey during the month of conception. Birth timing in conjunction with remote sensing and ecological factors were thus identified behaviors associated with denning.     

Roan (Hippotragus equinus) population decline in Kruger National Park, South Africa: influence of a wetland boundary

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.     

Effects of Chemical Immobilization on Survival of African Buffalo in the Kruger National Park

ABSTRACT Capturing, immobilizing, and fitting radiocollars are common practices in studies of large mammals, but success is based on the assumptions that captured animals are representative of the rest of the population and that the capture procedure has negligible effects. We estimated effects of chemical immobilization on mortality rates of African buffalo (Syncerus caffer) in the Kruger National Park, South Africa. We used a Cox proportional hazards approach to test for differences in mortality among age, sex, and capture classes of repeatedly captured radiocollared buffalo. Capture variables did not improve model fit and the Cox regression did not indicate increased risk of death for captured individuals up to 90 days postcapture [exp (β) = 1.07]. Estimated confidence intervals, however, span from a halving to a doubling of the mortality rate (95% CI = 0.56–2.02). Therefore, capture did not influence survival of captured individuals using data on 875 captures over a 5-year period. Consequently, long-term research projects on African buffalo involving immobilization, such as associated with research on bovine tuberculosis, should result in minimal capture mortality, but monitoring of possible effects should continue.     

Hominins, sedges, and termites: new carbon isotope data from the Sterkfontein valley and Kruger National Park

Stable carbon isotope analyses have shown that South African australopiths did not have exclusively frugivorous diets, but also consumed significant quantities of C4 foods such as grasses, sedges, or animals that ate these foods. Yet, these studies have had significant limitations. For example, hominin sample sizes were relatively small, leading some to question the veracity of the claim for australopith C4 consumption. In addition, it has been difficult to determine which C4 resources were actually utilized, which is at least partially due to a lack of stable isotope data on some purported australopith foods. Here we begin to address these lacunae by presenting carbon isotope data for 14 new hominin specimens, as well as for two potential C4 foods (termites and sedges). The new data confirm that non-C3 foods were heavily utilized by australopiths, making up about 40% and 35% of Australopithecus and Paranthropus diets respectively. Most termites in the savanna-woodland biome of the Kruger National Park, South Africa, have intermediate carbon isotope compositions indicating mixed C3/C4 diets. Only 28% of the sedges in Kruger were C4, and few if any had well-developed rhizomes and tubers that make some sedges attractive foods. We conclude that although termites and sedges might have contributed to the C4 signal in South African australopiths, other C4 foods were also important. Lastly, we suggest that the consumption of C4 foods is a fundamental hominin trait that, along with bipedalism, allowed australopiths to pioneer increasingly open and seasonal environments.     

Calibrating a camera trap–based biased mark–recapture sampling design to survey the leopard population in the N'wanetsi concession,Kruger National Park,South Africa

Estimating large carnivore abundance can be challenging. A biased leopard (Panthera pardus) population survey was conducted in the N'wanetsi concession in the Kruger National Park (KNP), South Africa, using motion‐sensitive camera traps from April to August 2008. Survey effort included 88 trapping occasions and 586 trap days. The survey yielded 24 leopard photographs, comprising fourteen adults of eleven males and three females. The capture rate was determined to be 24.4 trap days per leopard. Estimates of population abundance stabilized at approximately 500 trap days. Precision of population estimates began to stabilize after 378 trap days. We estimated that there were nineteen leopards in an area of 150 km². Leopard density was estimated at 12.7 leopards per 100 km². We explore the possibility of employing the methods used in this study to survey the leopard population in the KNP and surrounding areas.     

Landscape-scale sexual segregation in the dry season distribution and resource utilization of elephants in Kruger National Park, South Africa

This study compared the dry season distribution of elephant bull groups and mixed herds and the resources driving these distributions within Kruger National Park, South Africa. It is important to understand what resources drive the distribution of elephants as this may be of relevance to understanding and managing their impact. It is also important to distinguish between resource use by bull groups and mixed herds because their impact on the habitat may differ. Our results indicated that sexual segregation, both in space and in resource selection, did occur in Kruger Park. Bulls roamed more widely in the park, and although their distribution and resource use overlapped with mixed herds, they also occurred in areas that mixed herds apparently did not, or could not, utilize in the dry season. This gave rise to areas used exclusively by bulls but no areas used exclusively by mixed herds. Lower collective feeding requirements as a result of smaller group size, wider habitat tolerance, and increased mobility as a result of bigger body size, as well as conflict avoidance with musth bulls in areas with mixed herds, might have been some of the reasons for bull groups roaming more widely and for the establishment of separate bull areas. Rivers were an important resource driving both the distribution of the mixed herds and bull groups, but with the mixed herds occurring closer to these resource hot spots than the bull groups. Tree cover proved important for mixed herds, probably because of the importance of shade and the higher nutritional requirements of the smaller-sized cows and calves. Artificial waterholes might have opened up previously unutilized areas for bulls in the dry season, especially on the grassy basaltic plains in the north of the park. However, the distribution of the mixed herds suggested that they did not occur in higher densities in areas surrounding waterholes.     

The Evolution of Conservation Management Philosophy: Science, Environmental Change and Social Adjustments in Kruger National Park

In this ‘perspectives’ article, we share experiences gained from the century-old Kruger National Park (KNP) in South Africa to illustrate the dynamic complexity of biophysical and socio-political systems, the interactions that occur between them, and the consequences for ecosystem-scale functions and resources and for their management. As in KNP, the social-ecological milieu surrounding many national parks and protected areas is changing rapidly. There will be significant managerial adjustments as human populations grow and the needs for resources accelerate. The changes, driven largely by global-scale environmental shifts as well as by new knowledge, are intimately intertwined with evolving societal perceptions, values, and expectations. Many KNP resource-related issues of the past century originated more internally and were largely environmental, whereas the emerging issues are more external and largely social. Here, we illustrate how interrelated scientific and managerial advances in integrating biophysical and social systems are acting to conserve and rehabilitate resources within KNP, and to aid in their conservation. Where appropriate, we relate these advances to similar examples in the region or other protected areas in the world. Strategies to address emerging issues are identified and discussed—and their combined effects on resource conservation and management are evaluated. In our experience the approach to conservation within KNP has been successful, despite well-intended but damaging management actions in the past. We believe that the perceived success stems from a willingness to continually incorporate new knowledge into management, to foster close working and personal associations among scientists, managers, and rangers, to acquire an intimate knowledge and understanding of the social-ecological system by the administrators as well as by the staff, and to be actively ‘forward’ thinking in an increasingly complex and uncertain world. We accept that many decisions taken today will be challenged by future managers and scientists, and we expect that some will be found wanting as emerging knowledge and continued learning shape future decisions. Further, evolving political, social, and environmental contexts may mean that protected areas will need to be managed in different ways. Therefore, we emphasize the importance of minimizing the permanency and impact of decisions so that today’s actions do not compromise future decisions when meaningful changes need to be made.

Nonhuman Primates in the Namdapha National Park, Arunachal Pradesh, India

Namdapha National Park and Tiger Reserve in the Changlang District of Arunachal Pradesh in northeastern India are rich in biodiversity. The dense evergreen forest of the park with high canopy coverage supports a variety of fauna including primates. In February, 2002, we surveyed the primates in Namdapha National Park to assess their status. We directly sighted, 5 species of diurnal primates, and secondary information shows the presence of stump-tailed macaques and slow lories. We encountered 10 groups of hoolock gibbons (33 individuals), 9 troops of capped langurs (61 individuals), 15 groups of Assam macaques (209 individuals), 6 groups of rhesus macaques (74 individuals) and one unidentified group of macaques (15 individuals). Hunting, rather than habitat destruction, is the chief potential threat for primates in the park.     

张掖国家湿地公园优势鸟类种群生态位研究

鸟类时空格局影响下鸟类种群生态位的变化是认识鸟类环境适应机制的理论基础。在张掖国家湿地公园保育区,采用样带法研究了冬春季节5种优势鸟类种群生态位宽度和生态位重叠的时间异质性。结果表明:随着月份的更替,5种优势鸟类种群的生态位宽度呈现出先增大后减小的变化趋势,赤麻鸭(Tadornaferruginea)、绿头鸭(Anasplatyrhynchos)、麻雀(Passer montanus)、白骨顶鸡(Fulicaatra)的最高值出现在1月分别为1.601、1.415、1.627、1.771,大白鹭(Ardea alba)的最高值出现在3月为0.556;不同月份间鸟类优势种群生态位重叠存在差异,3月、11月生态位的重叠值最大,1月份最小;优势鸟类种群的生态位宽度和重叠在时间尺度上表现出"此消彼长"的关系。湿地公园时间尺度上的鸟类生态位宽度和重叠的差异与湿地食物资源及隐蔽条件、鸟类群体迁徙规律、鸟类种间的竞争密切相关,反应了湿地鸟类适应生境变化的可塑性机制。     

Primate population dynamics over 32.9 years at Ngogo, Kibale National Park, Uganda

We present census data for eight primate species spanning 32.9 years along the same transect at Ngogo, Kibale National Park, Uganda, demonstrating major changes in the composition of the primate community. Correlated with an estimated decline of ～89% in the red colobus population was an increase in encounter rates with chimpanzee parties. Our data, along with the unusually high rates of predation by chimpanzees on red colobus at Ngogo and the fact that the chimpanzee community at Ngogo is the largest ever recorded, support the conclusion that the red colobus decline was caused primarily by chimpanzee predation. This seems to be the first documented case of predation by one nonhuman primate causing the population decline in another. We evaluated disease and interspecific competition as other possible causes of the red colobus decline, but judged them to be relatively insignificant compared with predation by chimpanzees. Notable changes in encounter rates with other primate species may have resulted from forest expansion. Those for mangabeys, redtails, and black and white colobus increased significantly. Encounter rates increased for l'Hoest's monkeys too, but the increased sightings may have been an artifact of increased habituation. Sightings of blue monkey and baboon groups declined. There was no significant change in encounter rates for all species combined. The Ngogo primate community seemed to be in a nonequilibrium state, changing from one dominated by two species, a folivore (red colobus) and a frugivorous omnivore (redtails), to one dominated by three species of frugivorous omnivores (redtails, mangabeys, and chimpanzees). This study demonstrates the importance of long-term monitoring in understanding population dynamics and the role of intrinsic variables in shaping the species composition of a community.     

钱江源国家公园体制试点区鸟类多样性与区系组成

生物多样性编目是自然保护地有效管理与政策制定的基础。本研究收集整理了钱江源国家公园体制试点区(简称钱江源国家公园)内的鸟类记录, 数据来源包括专项鸟类调查、红外相机调查、自动录音调查、公众科学活动4大类。共记录到分属17目64科的252种鸟类。其中, 国家I级重点保护鸟类2种, 为白颈长尾雉(Syrmaticus ellioti)和白鹤(Grus leucogeranus), 国家II级重点保护鸟类34种; 在IUCN物种红色名录和中国脊椎动物红色名录中被评估为受威胁(即极危、濒危、易危和近危)的分别有10种和34种: 共计有46种鸟类为需受重点关注的物种, 占总物种数的18.25%。记录到4种浙江省鸟类新记录, 分别为黄嘴角鸮(Otus spilocephalus)、方尾鹟(Culicicapa ceylonensis)、远东苇莺(Acrocephalus tangorum)和蓝短翅鸫(Brachypteryx montana)。钱江源国家公园内鸟类组成兼具古北界和东洋界成分, 东洋种(45.24%)占比略高于古北种(42.46%); 留鸟和迁徙性鸟类的物种数近似; 繁殖鸟类中以东洋种为主(68.79%), 冬候鸟中则以古北种占绝对优势(94.83%)。本研究结果表明, 钱江源国家公园虽然面积有限(252 km ²), 但记录鸟种数占浙江全省的52%, 在鸟类多样性保护中有重要价值; 同时本研究的结果将为该国家公园管理以及未来的鸟类监测和研究提供基础本底。     

A comparison of methods used to count the elephant population of the Addo Elephant National Park, South Africa

Evaluation of alternative techniques used to estimate elephant population sizes is important in order to assess the accuracy of the results obtained, upon which management decisions may be based. Data from annual helicopter surveys carried out in the Addo Elephant National Park (1978–97) are compared with registration counts obtained from intensive ground surveys in which all elephants within the park are individually known. On average, total population size estimated in aerial surveys is 8.0% lower than registration counts (n₁₉₉₇ = 251), aerial calf (< 1 year) counts are 48.8% lower than registration counts, and aerial carcass counts are 50% below the total number of deaths documented in ground surveys. Registration counts provide more accurate demographic data than aerial surveys, the results of which are shown to vary widely and unpredictably, thus compromising their value. Where population estimates rely exclusively on aerial surveys, replicate counts are recommended in order to generate confidence intervals.     

The ecology of the hippopotamus in Liwonde National Park,Malawi: implications for management

The hippopotamus population in Liwonde National Park, Malawi was studied from December 2002 to June 2003. Motorboat censuses along the River Shire counted 640 animals, but because of the large number of hippos in temporary water sources at the time, the true number is probably closer to 950. Marked shifts in hippo distribution from the Shire into temporary water sources occurred as the wet season advanced. Because of the Shire’s year‐round water supply, the hippo population is not regulated by the availability of aquatic refuges, but by food availability. By following feeding tracks, dry season grazing range was estimated to extend 5 km east and 1 km west of the river. Grazing intensity transects and visual estimates indicated only a small portion of this area is suitable for hippo grazing, leading to over‐grazing in suitable areas. Coupled with low primary productivity levels in Liwonde, this means that dry season food competition between hippos and other herbivores is probably high. Recent proposals to raise the Shire’s dry season water level should be considered very carefully, as this will flood late dry season grazing grounds, thereby intensifying grazing competition and increasing grazing pressure in remaining grazing areas, having potentially serious impacts on the animal community.     

利用红外相机公里网格调查钱江源国家公园的兽类及鸟类多样性

2014年5月至2019年4月, 作者采用红外相机技术调查了浙江省钱江源国家公园的兽类及鸟类多样性。将整个国家公园划分为267个1 km × 1 km的调查网格, 每个网格内设置3个固定调查位点, 使用1台红外相机定期在同一网格内的位点之间进行轮换。其中, 古田山片区在5年内共完成14轮次调查, 古田山以外的区域自2018年7月纳入调查范围, 何田、长虹片区完成2次轮换, 齐溪片区完成1次轮换。在253个网格内的741个有效位点上共获得140,413个相机工作日的数据, 采集兽类和鸟类的照片和视频268,833份, 有效探测数74,368次, 鉴定出21种野生兽类, 72种野生鸟类, 5种家畜及家禽。包括国家一级重点保护野生动物2种, 即黑麂(Muntiacus crinifrons)、白颈长尾雉(Syrmaticus ellioti); 国家二级重点保护野生动物17种, 合计占野生物种总数的20.4%。被IUCN物种红色名录评估为易危(VU)的5种, 近危(NT)的4种, 合计占物种总数的9.7%。被中国脊椎动物红色名录评估为濒危(EN)的1种, 易危(VU)的9种, 近危(NT)的10种, 合计占物种总数的21.5%。相对多度指数最高的大中型兽类为小麂(Muntiacus reevesi), 鸟类为白鹇(Lophura nycthemera)。本次调查获得了国家公园内兽类和鸟类的多样性组成、空间分布和相对多度, 为长期科研监测和科学管理提供了基础数据。     

An unusual incident of adoption in a wild chimpanzee (Pan troglodytes) population at Gombe National Park

Allomothering and adoption are well documented across primate species. Multiple hypotheses have been proposed to explain the evolution of such behavior according to the costs and benefits to the caregiver, mother, and infant. Permanent adoptions and allomothering have been observed in chimpanzees, but they typically involve the infants' siblings or nulliparous females. Here, I report a unique incident of adoption where an infant was adopted by its grandmother without the death of its mother. I conclude by considering how the adoption may have benefited the grandmother, mother, and infant.