The white-backed vulture is found in lowland, open wooded savanna, especially areas of Acacia. Individuals often gather at carcasses, in thermals and at roost sites in tall trees. Their diet is exclusively carrion hence they provide essential ecosystem services in disposing of carcasses that could otherwise transmit disease. Along with all other vulture species, white-backed populations have undergone rapid decline in recent years. While trends are difficult to assess, their numbers are estimated to have more than halved in the last 50 years. Their long generation lengths and low reproduction rate mean vulture populations have little resilience to increased mortality rates.
The main threat to vulture populations in Tanzania is poisoning - both accidental from pesticides, vetinary use and that intended to kill livestock predators as well as increasing incidences of poachers intentionally killing vultures to avoid detection. Although poisoning is more common outside protected areas, given vultures large range size, there is a high risk of many birds coming into contact with poison at some point. Hunting of vultures for the traditional medicine trade is also an increasing threat, as is habitat loss due to agriculture. Reduced ungulate populations - resulting in less carrion - have also contributed to the vultures’ decline. In recognition of these ongoing threats, the species was uplisted to Endangered by the IUCN red list in 2012 and critically endangered in 2015.
The Ruaha-Katavi ecosystem is one of the few remaining strongholds for vultures in Africa, yet very little is known about their abundance, behaviour, nesting, breeding and population trends in this area. WCS is therefore undertaking research in collaboration with North Carolina Zoo with a view to developing effective conservation actions. Surveys of vulture abundance, using roadside counts, were begun in Katavi and Ruaha National Parks in 2013. While only three years of data is insufficient to give a truly accurate picture, results so far show that vulture populations are significant and have not changed dramatically during this time. It seems to indicate range expansion however, where vultures move out of both national parks during the wet season due to reduced food availability at that time.
Two white-backed vultures have been satellite tagged outside Ruaha National Park and will transmit 14 data points a day for at least a year. These data, combined with the roadside counts, will be used establish population ranges, discover important breeding sites, and determine principle mortality causes and rates. Road side counts are to be continued four times a year (twice in wet season and twice in dry season) along with systematic nest searches by car and aerial surveys when possible - all to further establish an accurate picture of vulture abundance and population trends.