Low birth rates and reproductive skew limit the viability of Europe's captive eastern black rhinoceros, Diceros bicornis michaeli

Ex situ populations play a critical role for the conservation of endangered species, especially where in situ populations face imminent threats. For such populations to act as vital reserves, they must be viable and sustainable. Eastern black rhinoceros (Diceros bicornis michaeli) epitomise the delicate nature of conservation, as a steady increase in the in situ population over the last two decades is threatened to reverse due to intense poaching pressures on rhinoceros across sub-Saharan Africa. This study utilized population viability analysis to evaluate the demographic and genetic viability of the European captive population of eastern black rhinoceros, and compared demographic parameters to in situ reference populations. Although self-sustaining, the ex situ population performs poorly relative to in situ counterparts, growing at a rate of only 1–2 % per annum compared to 6–8 % for managed wild populations. Captive females start reproducing later, have longer inter-calving intervals, and a lower proportion breed each year. Furthermore, over 40 % of reproductive-age animals have yet to reproduce, with additional implications for the maintenance of genetic diversity. Pedigree analysis highlights the unequal contribution of wild-caught founders to the current population; 69 % of which have no living descendants, and more than a third of the current population are related to five founders. This results in a current genome equivalent of just 13.39 equally reproducing founders. Although reproductive skew is not unusual in wild populations, it severely undermines efforts to maintain genetic and phenotypic diversity in captive breeding programmes. We suggest that understanding and alleviating the causes of reproductive skew must be an important consideration for small population management to maintain the genetic and demographic viability of ex situ populations. © 2015, Springer Science+Business Media Dordrecht

The behaviour and fate of translocated bull African savanna elephants (Loxodonta africana) into a novel environment

Translocation of elephants is used to mitigate human-elephant conflict in Asia and Africa. However, few studies investigate how translocations affect the movements and social behaviour of individuals following their release, which may have important implications for whether translocated animals survive and succeed. Using GPS-tracking data, we explored movements of five translocated bull elephants (Loxodonta africana) moved to Tsavo, Kenya, and compared them with five resident bull elephants. Position data was collected hourly for 1 year (March 2018–March 2019), and analysed to investigate home range, displacement rates, problematic behaviour and group size. Of the five translocated elephants, three were illegally killed and one continued to break fences and raid crops. Only one elephant stayed away from human settlement. We found group size and composition to be significantly different, with translocated elephants observed in smaller groups with no female elephant interactions. All elephants showed variation in home ranges and displacement rates, but differences were not significant between resident and translocated elephant groups. For future translocations, we recommend careful consideration of elephant social systems, elephant age, timing, release site and proximity to human settlements that might create human-elephant conflict. This will improve chance for success of such high-stake and expensive translocations

Effectiveness of wildlife underpasses and culverts in connecting elephant habitats: a case study of new railway through Kenya’s Tsavo National Parks

Transportation networks can be a major impediment to wildlife movements. We assessed the use of wildlife underpasses and culverts along a newly constructed railway in Kenya's Tsavo National Parks by African elephants (L. africana). We collared ten elephants with GPS satellite transmitters within 20 km of the railway in March 2016 and analysed their movement data to March 2019. Eight elephants used the underpasses although one did not cross the adjacent highway. The remaining two neither used the underpasses nor crossed the highway despite ranging in the vicinity. Their median speed significantly increased to 0.65 km/hr from 0.45 km/hr before crossing the railway, then slowed to 0.32 km/hr after crossing. Females in family groups moved faster than the lone bulls when using the underpasses. Seventy‐eight per cent of all crossings made were at night. The fast speeds and the nocturnal patterns are behavioural responses of elephants in risky landscapes or under stress. Disturbance from vehicles traffic on the adjacent highway and from newly developed human settlements may have limited use of underpasses. Wildlife crossing structures, signage and speed bumps along the highway; relocation of the illegal human settlements; and inter‐agency coordination are requisites for enhancing Tsavos' elephant habitat connectivity

Census and distribution of large carnivores in the Tsavo national parks, a critical east African wildlife corridor

Kenya's Tsavo National Parks are a critical conservation area and the only wilderness corridor through densely populated human-dominated landscapes stretching from the East African coast to Lake Victoria, separating extensive undeveloped grasslands south of the equator from the undeveloped semiarid bushlands to the north. At nearly 21,000 km(2), Tsavo is one of four lion strongholds in East Africa and part of Africa's most important populations of all other large African carnivores. To provide baseline data on the status of large carnivores, a track survey was undertaken in 2013. Lions and both hyaena species were widely distributed across both parks, while cheetahs and wild dogs were more patchily distributed. Spotted hyaenas were the most abundant, with an estimated population of 3,903 +/- 514 (95% CI), followed by lion (706 +/- 201), striped hyaena (679 +/- 144), leopard (452 +/- 98), cheetah (154 +/- 74) and wild dog (111 +/- 92). Tsavo's carnivores suffer from bushmeat poaching, illegal grazing and retaliatory killing, and increasing human numbers on its periphery. Given Tsavo's importance as a stronghold for lions and an ecological corridor, increased investment in effective protection is strongly recommended. Evaluating trends will require complementary techniques in light of intensive monitoring requirements