African vultures don’t follow migratory herds: scavenger habitat use is not mediated by prey abundance

Virani, M. Z., Kendall, C. J., Hopcraft, J. G. C. , Bildstein, K. L. and Rubenstein, D. I. (2014) African vultures don’t follow migratory herds: scavenger habitat use is not mediated by prey abundance. PLoS ONE, 9(1), e83470. (doi: 10.1371/journal.pone.0083470) (PMID:24421887) (PMCID:PMC3885425)

[img]
Preview
Text
97784.pdf - Published Version
Available under License Creative Commons Attribution.

4MB

Publisher's URL: http://dx.doi.org/10.1371/journal.pone.0083470

Abstract

The ongoing global decline in vulture populations raises major conservation concerns, but little is known about the factors that mediate scavenger habitat use, in particular the importance of abundance of live prey versus prey mortality. We test this using data from the Serengeti-Mara ecosystem in East Africa. The two hypotheses that prey abundance or prey mortality are the main drivers of vulture habitat use provide alternative predictions. If vultures select areas based only on prey abundance, we expect tracked vultures to remain close to herds of migratory wildebeest regardless of season. However, if vultures select areas where mortality rates are greatest then we expect vultures to select the driest regions, where animals are more likely to die of starvation, and to be attracted to migratory wildebeest only during the dry season when wildebeest mortality is greatest. We used data from GSM-GPS transmitters to assess the relationship between three vulture species and migratory wildebeest in the Mara-Serengeti ecosystem. Results indicate that vultures preferentially cluster around migratory herds only during the dry season, when herds experience their highest mortality. Additionally during the wet season, Ruppell’s and Lappet-faced vultures select relatively dry areas, based on Normalized Difference Vegetation Index, whereas White-backed vultures preferred wetter areas during the wet season. Differences in habitat use among species may mediate coexistence in this scavenger guild. In general, our results suggest that prey abundance is not the primary driver of avian scavenger habitat use. The apparent reliance of vultures on non-migratory ungulates during the wet season has important conservation implications for vultures in light of on-going declines in non-migratory ungulate species and use of poisons in unprotected areas.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Hopcraft, Dr Grant
Authors: Virani, M. Z., Kendall, C. J., Hopcraft, J. G. C., Bildstein, K. L., and Rubenstein, D. I.
College/School:College of Medical Veterinary and Life Sciences > Institute of Biodiversity Animal Health and Comparative Medicine
Journal Name:PLoS ONE
Publisher:Public Library of Science
ISSN:1932-6203
Copyright Holders:Copyright © 2014 The Authors
First Published:First published in PLoS ONE 9(1):e83470
Publisher Policy:Reproduced under a Creative Commons License

University Staff: Request a correction | Enlighten Editors: Update this record