Comparison of divergent breeding management strategies in two species of semi-captive eland in Senegal

Abstract

Breeding management of small populations may have a critical influence on the development of population characteristics in terms of levels of genetic diversity and inbreeding. Two populations of antelope sister species – Critically Endangered Western Derby eland (Tauroragus derbianus derbianus) and non-native Least Concern Cape eland (Taurotragus oryx oryx) bred under different management strategies were studied in Senegal, Western Africa. The aims of the study were to compare the population genetic parameters of the two species and to test for the presence of interspecific hybrids. In total, blood and tissue samples from 76 Western Derby elands and 26 Cape elands were investigated, using 12 microsatellite markers. No hybrid individuals were detected in the sampled animals within the multispecies enclosure in Bandia Reserve, Senegal. The parameters of genetic polymorphism indicated much lower genetic diversity in Western Derby elands compared to Cape elands. On the other hand, the coefficient of inbreeding was low in both species. It is hypothesized that this could be a positive effect of strict population management of Western Derby elands, which, despite the loss of genetic diversity, minimizes inbreeding.

Individual‐based assessment of post‐translocation fitness of ungulates: Lessons from the critically endangered Derby eland conservation programme

“…Even though such selections are vital, and decisively affect survival and reproductive rates (de Azevedo & Young, 2021; Tetzlaff et al, 2019), they are not always possible, especially in the case of species at the brink of extinction, because the source population is low, and may not provide a high diversity in behaviors and personalities anymore. In this case, and in the case of the WDE semi‐captive population, the genetic diversity and selection based on kinship and pedigree become a priority (Kubátová et al, 2020).…”

“…The conservation breeding management is based on the individual identification of each animal in the semi‐captive population. The individual identification of the animals in the Bandia reserve, and later in the Fathala reserve, has been regularly performed based on the unique patterns of the white stripes on their flanks (Koláčková et al, 2011), while kinship was determined through direct observations of suckling, and molecular genetic analyses were used to complete the pedigrees and any missing paternity information (Kubátová et al, 2020; Zemanová et al, 2015). The mean lifespan of WDE calculated from pedigree data was 6.7 years for males (maximum age 14 years) and 7.2 years for females (maximum age 16 years).…”

“…Western Derby eland is a critically endangered antelope with its conservation breeding program running in Senegal in two fenced nature reserves located in different types of savanna ecosystems. The conservation breeding management for this species involved short‐ and long‐distance translocations of breeding individuals to ensure the long‐term viability of the semi‐captive (fenced) small population (Kubátová et al, 2020).…”

Taxonomy and Translocations of African Mammals: A Plea for a Cautionary Approach

“…Hybridization between distinct taxa is a common result of translocations in South Africa, where several genera such as Connochaetes and Aepyceros are involved [21,84]. The same threat is now spreading elsewhere, a case in point being the managed populations of two Taurotragus species in the same area in Senegal; one being the critically endangered Taurotragus derbianus derbianus whose genetic integrity is potentially threatened by the imported T. oryx oryx-fortunately in this case, no hybrids have yet been detected based on microsatellite markers [73]. In the same private "reserves" in Senegal, several species, including Ceratotherium simum simum, Kobus ellipsiprymnus ellipsiprymnus, Tragelaphus strepsiceros strepsiceros, Aepyceros melampus melampus, Oryx gazella gazella, and Giraffa camelopardalis giraffa have been introduced from South Africa [71,72] (see also Table 1), which is a fact that raise some concern, especially in cases of animal escapes.…”

Spatially Restricted Occurrence and Low Population Abundance Estimates as Key Tools for the Conservation of the Critically Endangered Large Social Antelope in West African Savannah

“…According to former wildlife surveys carried out in the 1960's and 1970's, the WDE population number has always been estimated as very low, and never exceeded several hundred individuals [9][10][11][12]. The conservation actions for WDE have thus had a limited knowledge basis for decision-making, and rely mostly on ecological information gained indirectly from faeces in situ, such as their diet composition [13], or from studying the foraging strategy, social behaviour, and reproduction of the only ex situ population found within two other natural reserves in Senegal [14][15][16][17][18][19].…”