Abstract:
Hybridization between introduced and endemic ungulates, resulting from
Anthropogenic actions, have been reported for several species. Several studies of such events
contain the common themes of extralimital movements, problematic phenotypic and genetic
detection, and imperfect management. In southern Africa, the endemic black wildebeest
(Connochaetes gnou) currently faces a serious threat of hybridization and introgression. This
species survived near extinction and consequent genetic bottlenecks in the late 1800s and in the
1930s. Initiatives by private farmers followed by conservation authorities led to a dramatic
recovery in numbers of this species. However, in an ironic twist, the very same advances in
conservation and commercial utilisation which lead to the recovery of numbers are now
themselves threatening the species. Injudicious translocation has brought the species into contact
with its congener, the blue wildebeest (Connochaetes taurinus), and in recent times, hybridization
between the species has occurred at numerous localities in South Africa. Consequently, a
significant proportion of the national black wildebeest population potentially carries a proportion
of introgressed blue wildebeest genetic material. We discuss completed and ongoing attempts to find molecular markers to detect hybrids and highlight the difficulty of detecting advanced
backcrosses. Additional avenues of research, such as work on morphology (cranial and
postcranial elements), estimating of the probability of introgression and modelling of diffusion
rates are also introduced. In addition to the difficulty in detecting hybrid animals or herds, the
lack of consensus on the fate of hybrid herds is discussed. Finally, in an environment of
imperfect information, we caution against implementation of management responses that will
potentially induce a new genetic bottleneck in C. gnou.
