Causes and Effects of Temporospatial Declines of Gyps Vultures in Asia

There are eight species in the genus Gyps : Gyps africanus , G. coprotheres, and G. rueppellii in Africa; G. bengalensis , G. indicus , G. tenuirostris , G. himalayensis in Asia; G. fulvus in Europe, Africa, and Asia. The ranges of many of these species overlap, and wintering G. fulvus overlap with several resident species in Asia and Africa (Fig. 1). Gyps species share a similar feeding ecology, scavenging the soft tissues of large mammals, usually ungulates. They tend to be colonial nesters and communal feeders, feeding alongside conspecifics and other vulture species. Densities of Gyps vultures can be high in areas with suitable breeding habitat and abundant carrion. An extreme example is G. bengalensis , which often lives in close association with humans. During the 1970s and early to mid-1980s, densities of 12 nests/km 2 were recorded at Keoladeo National Park, Rajasthan, India (Prakash 1989), and there were nearly 3 nests/km 2 in the city of Delhi (Galushin 1971), where flocks of several thousand birds were present at carcass dumps. As recently as 1985, G. bengalensis was regarded as “possibly the most abundant large bird of prey in the world” (Houston 1985). Despite Gyps population declines across Southeast Asia, until recently only one species of Africa, G. coprotheres, was considered globally threatened (vulnerable; BirdLife International 2000), largely because of the indiscriminate use of poisons in southern Africa (Mundy et al. 1992). Following the recent population crash in Gyps species across the Indian subcontinent, three other species, G. bengalensis, G. indicus, and G. tenuirostris , are now listed as critical ( BirdLife International 2000), placing them among the most threatened birds in the world.