Hybridization following population collapse in a critically endangered antelope

Area of Science:

• Conservation Biology
• Genetics
• Wildlife Management

Background:

• Population declines can increase interspecific hybridization risk, a phenomenon known as "desperation" hypothesis.
• Confirming wild hybridization and its demographic impact has been challenging.
• Critically endangered giant sable antelope (Hippotragus niger variani) face extinction risks.

Purpose of the Study:

• To document demographic processes of introgressive hybridization between giant sable and roan antelopes (H. equinus).
• To investigate hybridization driven by population depletion and mate scarcity.
• To inform conservation strategies for small, endangered populations.

Main Methods:

• Combined seven-year camera-trapping and molecular surveys.
• Documented demographic processes and identified hybrid phenotypes.
• Monitored population dynamics and herd composition.

Main Results:

• Confirmed introgressive hybridization, including backcrosses, in a giant sable population.
• Hybridization occurred following severe population depletions from poaching.
• A mixed herd of sable females and hybrids formed and grew, increasing hybridization risk.

Conclusions:

• Interspecific hybridization due to mate scarcity is a growing conservation concern for declining populations.
• Early detection of hybrids is crucial for managing small populations.
• Conservation actions, including translocation and confinement, were implemented to prevent further hybridization and aid recovery.