Population trends of Critically Endangered Gyps vultures in the lowlands of Nepal

Abstract

SummaryThree species of resident Gyps vulture are threatened with extinction in South Asia due to the contamination of domestic ungulate carcasses with the drug diclofenac. Observed rates of population decrease are among the highest recorded for any bird species, leading to total declines in excess of 99.9% for the Oriental White-backed Vulture Gyps bengalensis in India between 1992 and 2007. Vultures have declined in Nepal, but quantitative information on the rate and scale of decreases is unavailable. Road transect surveys for vultures, following the same route, methodology and timing, were undertaken in lowland areas of Nepal for seven years from 2002 to 2011. The seven survey transects followed Nepal's East-West highway and covered 1,010 km in three years of the survey, and 638 km in the remaining four years. Slender-billed Vultures G. tenuirostris were very scarce, with a maximum of five individuals in 2002 and none recorded in 2010 and 2011. Oriental White-backed Vultures were most commonly recorded, but decreased from 205 to 68 birds over the survey period, with an estimated annual rate of decline of 14% a year. If population decreases commenced in Nepal in the same year as in India, then Whitebacked Vultures in Nepal have declined by 91% since the mid-1990s. Few resident Gyps vultures remained in Eastern and Central regions of Nepal, with just one, nine and six birds recorded in the three surveys that covered these regions. The majority of threatened Gyps vultures in lowland Nepal are now found in Western and Mid Western regions, where conservation efforts have been focused in the last six years. Removing veterinary diclofenac from across the country and continuing to manage effective "vulture safe zones" are essential to conserve Nepal's remaining vulture populations.

The conservation of Accipitridae vultures of Nepal: a review

“…The global population is estimated to be about 45,000 mature individuals (Birdlife International 2012). (Gilbert et al 2006;Prakash et al 2007;Pain et al 2008;Chaudhary et al 2012 Slender-billed Vulture (Fig. 4) Slender-billed Vultures range through southern Nepal.…”

Population and breeding success of Red-headed Vulture <i>Sarcogyps calvus</i> and Egyptian Vulture <i>Neophron percnopterus</i> in central west Nepal

“…The smaller number of Red-headed Vultures estimated in this study could be due to their highly territorial behaviour. Road transect surveys conducted by Chaudhary et al (2012) also revealed very low numbers of Red-headed Vultures in lowland areas of the country. In South Asia and a country such as Nepal, where wild ungulates are no longer a primary food source, the Red-headed Vulture is largely dependent on the carrion of domestic livestock (Birdlife 2012).…”

“…Based on active nests as a primary unit, the breeding success of Egyptian Vulture was 62.5% for nine nests identified in breeding year 2012; average nesting cliff/tree height was 27.8 m and that of nests was 14.8 m. In the study we did not find any Red-headed Vulture nests, however fresh juvenile birds were recorded repeatedly in the autumn season. (Oaks et al 2004, Green et al 2004, Pain et al 2008, and populations of several vulture species have undergone some of the most rapid declines ever recorded (Prakash et al 2003, Prakash et al 2007, Cuthbert et al 2006, Chaudhary et al 2012. Studies conducted in Nepal, India and Pakistan show three species of resident Gyps vulture (White-rumped Gyps bengalensis, Long-billed Gyps indicus and Slender-billed Vulture Gyps tenuirostris) have undergone >97% population declines (Baral et al 2004, Prakash et al 2007.…”

Himalayan Vultures in Khodpe, far-west Nepal: is there any threat?

“…The Government of Nepal has banned the veterinary use of diclofenac in Nepal, but illegal availability of diclofenac cannot be ignored because animal husbandry is one of the important sources of income in the high lands (Acharya et al 2009;Lu et al 2009;Chaudhary et al 2011;DNPWC 2015). Like in our study, Karmacharya (2011), Bhusal (2011 and Harris (2013) also speculated loss of food, loss of nesting sites, poisoning of carcasses, pesticides, forest fire and destruction of cliffs for roads as limiting factors for the survival of Himalayan Vultures.…”

“…This ultimately increases the probability of them coming in contact with diclofenac. Although the Nepalese and Indian government have banned the veterinary use of diclofenac since 2006 (Chaudhary et al 2011;Cuthbert et al 2011), and have promoted the use of meloxicam, which is safe alternative drug for the vultures (Harris 2013), it is still used illegally in some parts of the country.…”