Using Africa's protected area network to estimate the global population of a threatened and declining species: a case study of the Critically Endangered White-headed Vulture Trigonoceps occipitalis.

摘要: The White-headed Vulture Trigonoceps occipitalis (WhV) is uncommon and largely restricted to protected areas across its range in sub-Saharan Africa. We used the World Database on Protected Areas identify (PAs) likely contain Vultures. occurrence road transects Southern, East, West Africa was adjusted nests per km(2) using data from with known numbers of corresponding transect data. Nest density calculate number WhV within identified PAs there extrapolated estimate global population. Across a fragmented range, 400 are estimated 1893 nests. Eastern 721 nests, Central 548 Southern 468 156 Including immature nonbreeding birds, accounting for deficient PAs, population 5475 - 5493 birds. distribution highlights alarming: over 78% (n = 313) fewer than five A further 17% (n = 68) 5 20 4% (n = 14) >20 Just 1% (n = 5) >40 nests; none located Whilst ranging behavior WhVs currently unknown, 35% large enough hold isolated by more 100 km other PAs. Spatially discrete unpredictable mortality events such as poisoning pose major threats small localized vulture populations will accelerate ongoing local extinctions. Apart reducing threat events, conservation actions promoting linkages between should be pursued. Identifying potential assisted re-establishment via translocation offers expand this species alleviate risk.