Satellite technology pinpoints behaviour of rare vultures

Phnom Penh, Cambodia – On June 21, 2005, BirdLife International and the Wildlife Conservation Society have announced a significant advance in the understanding and conservation of threatened vultures in Indochina. [1, 2, 3]

Attempts to capture and study vultures in the dry forests landscape of northern Cambodia have proved challenging. Following a lengthy, concerted trapping effort in May 2005, WCS researchers were rewarded with the successful capture of seven vultures (three Slender-billed Vultures, two White-rumped Vultures, and two Red-headed Vultures). This trapping exercise was conducted while carrying out a “vulture restaurant” in Chhep District, Preah Vihear Province, northern Cambodia. [4]

All birds were wing-tagged, leg-banded, and three birds (two Slender-billed and one White-rumped) were fitted with satellite transmitter units provided by the Royal Society for the Protection of Birds (RSPB; BirdLife in the UK) and released. Samples also were collected to determine the health status of the birds and their exposure to infectious disease.

Satellite tracking provides an accurate, up-to-date, landscape overview of vulture behaviour and ranging patterns. Maps of the three satellite tagged vultures from May 2005 show that all 3 birds left the trapping area soon after capture and settled quite close to each other approximately 80 km to east. The greatest distance was covered by the White-rumped Vulture who travelled considerably further than the others, drifting through five provinces. One of the Slender-billed Vultures travelled north at one point settling along the Mekong River in southern Laos.

Vultures are examples of what conservationists call “dispersed species” that range at low population densities over very large areas in search of food. "Hunting of Cambodia’s wild ungulates has greatly reduced the availability of food for the vultures, forcing them to forage over wider areas, and exposing them to risks beyond the confines of limited protected areas. This satellite tracking methodology has been used effectively in parts of South Asia and will provide a critical insight into the movements and home range of these vultures across the entirety of Cambodia’s dry forest landscape," notes Martin Gilbert, Regional Field Veterinarian for WCS Cambodia.

"By fixing satellite transmitters and monitoring vulture movements, we develop a greater understanding of their range size, habitat preferences, and seasonal movements. This increased understanding of ecological parameters allows us to develop more effective, targeted conservation actions and management guidelines," states Dr Sean Austin, Programme Manager for BirdLife International’s Cambodia Programme Office.

Contacts

Dr Sean C. Austin at BirdLife International - Cambodia Programme Office
Tel. +855-23-993-631, austin.birdlife@online.com.kh

Mr Joe Walston at Wildlife Conservation Society - Cambodia
Tel: +855-23-217-205, jwalston@wcs.org

1. BirdLife International is a global alliance of conservation organisations working in more than 100 countries who, together, are the leading authority on the status of birds, their habitats and the issues and problems affecting bird life.
2. Three species of Asian vultures (White-rumped Vulture Gyps bengalensis, Slender-billed Vulture Gyps tenuirostris, and Indian Vulture Gyps indicus) in South Asia have declined dramatically over the past decade and are now facing imminent extinction. Recorded population declines in India are over 97% since 1993 and 30-40% annually in Pakistan. Research has revealed that these declines are caused by veterinary use of the drug Diclofenac. All three of these vulture species are presently considered critically endangered. If the populations of these species in South Asia decline to extinction, only two disparate wild populations of two species (White-rumped and Slender-billed Vultures) will exist, one in north-eastern Cambodia and southern Lao PDR and one in Myanmar.
3. Vultures in Cambodia are threatened mainly by a lack of available food, and by direct persecution through hunting, capture for the pet trade or for their perceived medicinal value. If the Cambodian population is to be maintained these activities must be prevented. Fortunately at this stage there are relatively few barriers to successful conservation: vultures have little market value, supplementary feeding is relatively simple and Diclofenac is not available for veterinary use. Vulture research in Cambodia is led by a team of conservationists from BirdLife International, the Wildlife Conservation Society (WCS), the World Wide Fund for Nature (WWF), the Wildlife Protection Office (WPO) of the Forestry Administration (FA), and the Department of Nature Conservation and Protection (DNCP) of the Royal Government of Cambodia.
4. Vultures play an important ecological role in their environment where they have been relied upon for millenia to remove dead livestock and other dead animals, even human corpses. Experts have warned that diseases such as rabies and anthrax may spread more easily without the effective scavengers who are able to dispose of dead animals in a matter of hours.

Diclofenac

Diclofenac is a non-steroidal anti-inflammatory drug (NSAID) similar to ibruprofen or Tylenol. There is strong scientific evidence indicating it is the key factor in recent dramatic vulture declines. In even small quantities, diclofenac causes rapid death by visceral gout arising from kidney failure., a condition found in over 85% of vultures found dead in the field. Further facts are contained within Oaks et al. 2004, Diclofenac residues as the cause of vulture population decline in Pakistan, Nature 427: 630-633. The drug is considered so toxic to vultures that the observed population declines may have been caused by the contamination of as few as 1 in 1,000 livestock carcasses. Recent meetings in Nepal and India, involving countries from all range states, concluded that the use of Diclofenac in veterinary therapeutics must cease if remaining vulture populations are to survive. The drug is used in human medicine in Cambodia, but products are not available for veterinary use giving the Cambodian vultures an excellent chance of survival.

Globally threatened species

The World Conservation Union (IUCN) Red List criteria for species of conservation concern are: Critically Endangered (facing an extremely high risk of extinction in the wild in the immediate future), Endangered (facing a very high risk of extinction in the wild in the near future), Vulnerable (facing a high risk of extinction in the wild in the medium-term), Conservation Dependent (the focus of a conservation programme which, if stopped, would result in the species qualifying for one of the threatened categories), and Near Threatened (not CD but close to qualifying for Vulnerable).

Conservation Actions

A collaborative Vulture Conservation Project has been initiated by WCS, BirdLife International, WWF, and the Ministries of Environment and Agriculture, Forestry, and Fisheries of the Royal Government of Cambodia. This project aims to coordinate conservation activities for vultures and to develop a specific action and management strategy aimed at protecting vultures across the northern landscape of Cambodia.

BirdLife International and WCS believe that the next priorities in the battle to save Gyps vultures from extinction in Cambodia are:

1. Limiting the use of Diclofenac in key vulture landscapes and the promotion of suitable alternatives
2. Maintaining a monitoring program whose goal is to determine vulture population dynamics and trends
3. Protection and monitoring of breeding sites

Birdlife International and Wildlife Conservation Society are solely responsible for the contents of this press release and technical notes.  It has not been reviewed by the Horizon Scientific Review Board.