Critically endangered vulture shows signs of reproductive resilience in Nepal

Finally, some good news for vultures — according to a new paper published in the Journal of Raptor Research, two colonies of nesting white-rumped vultures (Gyps bengalensis) demonstrated stable reproductive rates over an 11-year study in an Important Bird and Biodiversity Area of central-western Nepal. These colonies represent two of the last remaining breeding sites for white-rumped vultures, a species that, in the 1980s, was considered the most abundant large raptor in the world. From 2002 to 2011 white-rumped vultures underwent a 91% decline in Nepal. Now, they are listed as critically endangered globally. Hence, this paper’s findings are uplifting.

Researchers visited the colonies three times per breeding season between 2010 and 2021 to monitor nesting success, observe nest site characteristics, and glean an understanding of population trends. The results were positive. The proof was in the productivity, a term referring to the number of nestling vultures that successfully fledged per occupied nest. Over the course of the study, the number of occupied nests increased, and productivity appeared stable.

These pairs are nesting within the Argha Important Bird and Biodiversity Area, a globally significant landscape designated in 2015 for the sake of globally threatened birds, including the white-rumped vulture and two other struggling vulture species.

White-rumped vultures are native to Asia. Like other vultures, they provide an essential ecosystem service through their efficient removal of carcasses. This is especially true in Nepal, where cattle are raised for milk but not for meat, resulting in many uneaten carcasses. Globally, 75% of vulture species are listed as either endangered or critically endangered by the International Union for the Conservation of Nature (IUCN). These declines are the direct result of human actions including the use of an anti-inflammatory drug for cattle called diclofenac, which causes kidney failure in vultures, killing them en masse due to their communal feeding behavior. The swiftness of these population declines resulted in a domino effect of consequences, such as the spread of diseases and their mammalian vectors. Vultures were the clean-up crew. 

Communities across the world rallied to ban diclofenac and establish vulture conservation programs. Along with India, Nepal was among the first. Lead author of the Journal of Raptor Research paper, Krishna Prasad Bhusal, with Bird Conservation Nepal, notes the importance of this study in confirming the efficacy of vulture conservation initiatives established in Nepal, which hinged on the involvement of locals. This support included the creation in 2009 of Vulture Safe Zones, defined as “an area surrounding one or more wild vulture nesting colonies, large enough to encompass the mean foraging range completely free of diclofenac use.” These zones, Bhusal says, combined with community awareness, have “definitely supported this species’ conservation.”

Bhusal and his coauthors mention several other interesting findings in their paper — nearly all of the vulture pairs nested in chir pines (Pinus roxburghii), a tree native to the Himalayas, and of clear importance to nesting vultures. Additionally, in 2021 they saw the highest number of occupied nests during their study with a whopping 24.

Together, the outcomes of this study demonstrate the capacity of fervent and localized conservation to turn things around. Bhusal says people living near the study site are “motivated and proactive in contributing to the protection of vultures in the area,” and participate annually in International Vulture Awareness Day (yes, this day does exist). He hopes to study the impact of climate change and other anthropogenic influences on breeding activities of white-rumped vultures and continue monitoring the two colonies. Ideally, this study will be replicated elsewhere. Conservationists agree that we must expand our collective knowledge of endangered vultures and the ecosystem parameters that will allow them to fill the skies once again.

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Paper

Krishna Prasad Bhusal, Ankit Bilash Joshi, Deu Bahadur Rana, Deelip Chand Thakuri, and Christopher J. W. McClure "Population and Productivity of the Critically Endangered White-Rumped Vulture (Gyps bengalensis) in the Argha Important Bird and Biodiversity Area, Nepal," Journal of Raptor Research 57(3), 352-358, (25 May 2023). https://doi.org/10.3356/JRR-22-61

Notes to Editor:

1. The Journal of Raptor Research (JRR) is an international scientific journal dedicated entirely to the dissemination of information about birds of prey. Established in 1967, JRR has published peer-reviewed research on raptor ecology, behavior, life history, conservation, and techniques. JRR is available quarterly to members in electronic and paper format.

2. The Raptor Research Foundation (RRF) is the world’s largest professional society for raptor researchers and conservationists. Founded in 1966 as a non-profit organization, our primary goal is the accumulation and dissemination of scientific information about raptors. The Foundation organizes annual scientific conferences and provides competitive grants & awards for student researchers & conservationists. The Foundation also provides support & networking opportunities for students & early career raptor researchers.