Figure 2. Temporal variation in estimated population size and births of giant sable antelopes and sable x roan hybrids in Cangandala National Park, Angola.

The number of hybrids recorded grew progressively over time (red line), while the number of sable observed increased up to 2006 and declined thereafter (blue line). We recorded births of male (dark blue bars) and female sables (light blue bars) between 2002 and 2005, and then again in 2010–2011, when all sables in Cangandala were taken to a large outdoor enclosure, to where sables captured in Luando National Park were translocated. Male (dark orange bars) and female (light orange bars) putative hybrids were estimated to be born each year until 2010, when access of roan to sable females was prevented. Arrow indicates the first introduction of a giant sable bull translocated from the Luando Integral Nature Reserve.