Foraging Ranges of Immature African White-Backed Vultures (Gyps africanus) and Their Use of Protected Areas in Southern Africa

Abstract

Vultures in the Gyps genus are declining globally. Multiple threats related to human activity have caused widespread declines of vulture populations in Africa, especially outside protected areas. Addressing such threats requires the estimation of foraging ranges yet such estimates are lacking, even for widespread (but declining) species such as the African white-backed vulture (Gyps africanus). We tracked six immature African white-backed vultures in South Africa using GPS-GSM units to study their movement patterns, their use of protected areas and the time they spent in the vicinity of supplementary feeding sites. All individuals foraged widely; their combined foraging ranges extended into six countries in southern Africa (mean (± SE) minimum convex polygon area = 269,103±197,187 km2) and three of the vultures travelled more than 900 km from the capture site. All six vultures spent the majority of their tracking periods outside protected areas. South African protected areas were very rarely visited whereas protected areas in northern Botswana and Zimbabwe were used more frequently. Two of the vultures visited supplementary feeding sites regularly, with consequent reduced ranging behaviour, suggesting that individuals could alter their foraging behaviour in response to such sites. We show that immature African white-backed vultures are capable of travelling throughout southern Africa, yet use protected areas to only a limited extent, making them susceptible to the full range of threats in the region. The standard approach of designating protected areas to conserve species is unlikely to ensure the protection of such wide-ranging species against threats in the wider landscape.

Carrion ecology modelling for vulture conservation: are vulture restaurants needed to sustain the densest breeding population of theAfrican white‐backed vulture?

“…For instance the average movement recorded in the Serengeti was 51 km and in Kruger 34 km (Mundy et al, 1992). A more recent study of immature African Whitebacked Vultures showed a mean distance travelled per day of 33.39 km (Phipps et al, 2013). It has been noted that, while nesting without a chick, the birds can fly over 240 km between the nest and a carcass and this is consistent with our value of 260 km (Houston & Cooper, 1975).…”

Medicating the environment: assessing risks of pharmaceuticals to wildlife and ecosystems

“…Scavengers, for example, can be reliant on carcases of livestock or companion animals for food, often from landfills or provided as a conservation measure. This brings with it the potential for exposure to veterinary drugs used to treat domesticated animals [14,65]. For example, residues of barbiturates in carrion of euthanized pets have been found to exceed the lethal dose for a spectrum of scavengers and there have been reports of secondary barbiturate poisoning [14].…”

Anthropogenic activities influence the abandonment of Bearded Vulture (Gypaetus barbatus) territories in southern Africa

“…Livestock graze throughout the species' foraging range and are scavenged from communal grazing lands in Lesotho or commercial livestock farms in South Africa, whereas wild ungulates are scavenged predominantly from protected areas. Related to our food shortage hypothesis, we also investigated whether the presence of more predictable food resources, in the form of supplementary feeding sites, influences territory occupancy because many other vulture populations have been found to be heavily reliant on supplementary feeding (Piper 2005, Deygout et al 2009, Cortés-Avizanda et al 2010, Phipps et al 2013. Although livestock and wild ungulate density is an indirect measure of food availability, we used this as a surrogate for the availability of carrion and predicted that if food supply influences territorial occupancy then it would be positively related to the number of ungulates and the presence of supplementary feeding sites in the landscape.…”