Conservation reinforcement of an introduced population of hirola antelope into Tsavo East National Park, Kenya

Summary

The hirola antelope (Beatragus hunteri), recently confirmed as the sole survivor of its own genus and Critically Endangered after crashing from roughly 14,000 animals in the mid-1980s to about 1,000 today, mostly from recurrent rinderpest epidemics, survives in a small introduced Tsavo East National Park population founded by 30 immature animals released in 1963. The Zoological Society of London and Kenya Wildlife Service organized a 2004 reinforcement translocation to boost this population's poor genetic base and improve on 1963's high capture mortality, forming a multi-agency Hirola Task Force with British Army logistical support and South African capture specialists to develop improved net-based capture protocols. Political opposition, including a court injunction from part of the Somali community, forced a shift partway through from net capture to helicopter-based chemical darting, which proved riskier: of 35 hirola captured, six died, five from capture-related stress. The 29 released hirola were radio-collared and ear-tagged; 55% survived to two years, and while the first pregnant translocated females lost their calves, subsequent births produced surviving offspring, with surviving males believed to be contributing to breeding. Despite reinforcement, the Tsavo population has remained roughly static around 100 animals, held back by predation, poaching and livestock competition. Major difficulties included a remote, insecure operating area, historical community hostility toward wildlife authorities, and the species' physiological fragility under capture stress. The project rates itself Partially Successful, crediting improved scientific knowledge and conservation awareness over demonstrated population growth.