The paper appears in the online edition of Bird Conservation International. Authors include: Tom Clements, Martin Gilbert, and Hugo J. Rainey of the Wildlife Conservation Society; Richard Cuthbert of the Royal Society for the Protection of Birds; Jonathan C. Eames of BirdLife International in Indochina; Pech Bunnat and Song Chansocheat of the Ministry of the Environment, Royal Government of Cambodia; Seng Teak of the World Wide Fund for Nature -- Cambodia Program; and Tan Setha of the Ministry of Agriculture, Forestry, and Fisheries, Royal Government of Cambodia.
"Results from vulture censuses from the past several years have been encouraging, with new nests recorded and even population increases," said WCS researcher Tom Clements, lead author on the new paper. "With continued investment, these critical populations can survive and grow."
In the study, which began in 2004, the authors collected data from several sites in Cambodia, Lao PDR, and Vietnam through a variety of methods, including monitoring of vulture nesting sites and feeding stations; health assessments of vultures; interviews with government officials, hunters, and wildlife traders to collect data on threats; and satellite transmitter vests on four birds to assess ranging patterns.
The findings: while Cambodia's vulture populations remain robust, the use of poison by hunters and fishers for capturing other species are leading to unintended vulture mortalities. According to the data, 74 percent of the 42 recorded mortalities during the study period were attributable to poison. Direct persecution (the shooting of vultures with guns and slingshots) was also significant, accounting for 10 percent of recorded vulture mortality.
The extreme importance of Cambodia's vulture population was created by an ecological disaster across Asia due largely to the veterinary drug diclofenac. Widely used as an anti-inflammatory drug for cattle in South Asia, diclofenac is toxic to vultures, causing death through renal failure and visceral gout to birds that feed on the cattle carcasses. It has led to a global population declines higher than 99 percent in some vulture species.
So far, the drug has not impacted the vulture populations of Cambodia because diclofenac is not used. WCS and other partners have actually recorded increases in some species of vulture in these areas. However, vultures in Cambodia are largely dependent on domestic animals for food, as populations of wild species such as gaur and Eld's deer remain low.
"Fortunately, the Royal Government of Cambodia has instituted measures to ban diclofenac to ensure the survival of these important birds," said Joe Walston, Director of WCS's Asia Program. "The challenge now is to reduce the indirect and direct persecution of vultures, specifically from poisoning and shooting, and longer-term pressures from habitat loss."
The slender-billed vulture, white-rumped vulture, and red-headed vulture are all listed as "Critically Endangered" by the International Union for Conservation of Nature.
The Cambodia Vulture Conservation Project is a collaboration between the General Department of Administration for Nature Conservation and Protection (GDANCP) of the Ministry of Environment (MoE), the Forestry Administration (FA) of the Ministry of Agriculture, Forestry and Fisheries (MAFF), the Wildlife Conservation Society (WCS), BirdLife International in Indochina, World Wide Fund for Nature (WWF), the Angkor Centre for Conservation of Biodiversity (ACCB) and Wildlife Alliance. This work has been made possible through the generous support of the Royal Society for the Protection of Birds (RSPB), the Disney Worldwide Conservation Fund, the Global Environment Facility -- United Nations Development Program, the Darwin Initiative and the Critical Ecosystem Partnership Fund. The Critical Ecosystem Partnership Fund is a joint initiative of l'Agence Française de Développement, Conservation International, the Global Environment Facility, the Government of Japan, the MacArthur Foundation and the World Bank.