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A clear and present danger: impacts of poisoning on a vulture population and the effect of poison response activities

  • Campbell Murn (a1) and André Botha (a2)
Abstract
Abstract

Vultures in Africa are being poisoned deliberately by poachers to prevent the birds alerting authorities to the poachers’ illegal activities, or for harvesting and sale of body parts for use in witchcraft. Hundreds of vultures can be killed at a single poisoned elephant Loxodonta africana carcass, and although field staff trained in poison response activities can limit the damage, mortalities remain numerous. We used the population viability analysis programme VORTEX to simulate seven 100-year-long scenarios investigating various rates of poisoning mortalities and the remedial effects of poison response activities on a population of Critically Endangered white-backed vultures Gyps africanus breeding in Kruger National Park, South Africa. In six scenarios the population declined (λ < 1); in three scenarios the population remained extant over the 100-year simulations but declined by 60–90% from a starting size of 2,400 individuals. In two scenarios one poisoned elephant carcass left untreated and causing the greatest number of vulture deaths was modelled as a catastrophic event with a 50% probability of annual occurrence, which resulted in a 100% probability of population extinction, with a mean time to extinction of 55–62 years. Effective poison response activities were modelled as a 70% reduction of mortality at each poisoned elephant carcass and resulted in population persistence after 100 years but with a c. 90% reduction in size (final n = 205). We highlight that although poison response activities will not prevent poisoning from occurring, they form an essential part of wider conservation actions designed to prevent local extinctions of vultures or other vulnerable species.

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Corresponding author
(Corresponding author) E-mail campbell@hawkconservancy.org
References
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Allan D.G. (2015) Hooded vulture Necrosyrtes monachus . In The 2015 Eskom Red Data Book of Birds of South Africa, Lesotho and Swaziland (eds Taylor M.R., Peacock F. & Wanless R.M.), pp. 5860. BirdLife South Africa, Johannesburg, South Africa.
Anderson M.D. & Kruger R. (1995) Power line electrocution of eighteen African white-backed vultures. Vulture News, 32, 1618.
Bennett E.L. (2015) Legal ivory trade in a corrupt world and its impact on African elephant populations. Conservation Biology, 29, 5460.
Bennett P.M. & Owens I.P.F. (1997) Variation in extinction risk among birds: chance or evolutionary predisposition? Proceedings of the Royal Society B, 264, 401408.
BirdLife International (2015) IUCN Red List for Birds. Http://www.birdlife.org [accessed November 2015].
Booth V.R. & Dunham K.M. (2016) Elephant poaching in Niassa Reserve, Mozambique: population impact revealed by combined survey trends for live elephants and carcasses. Oryx, 50, 94103.
Botha A. (2015) 65 endangered vultures killed in poisoning incident. Africa Geographic. Http://africageographic.com/blog/65-endangered-vultures-killed-in-poisoning-incident [accessed 1 June 2015].
Butchart D. (1987) 65 African white-backed vultures die in poisoning incident. Vulture News, 17, 2728.
Carrete M., Donázar J.A. & Margalida A. (2006) Density-dependent productivity depression in Pyrenean bearded vultures: implications for conservation. Ecological Applications, 16, 16741682.
Chantepie S., Teplitsky C., Pavard S., Sarrazin F., Descaves B., Lecuyer P. & Robert A. (2016) Age-related variation and temporal patterns in the survival of a long-lived scavenger. Oikos, 125, 167178.
Conrad K. (2012) Trade bans: a perfect storm for poaching? Tropical Conservation Science, 5, 245254.
Emslie R. (2013) African rhinoceroses—Latest trends in rhino numbers and poaching. CoP 16, IUCN, Bangkok, Thailand.
Fernández C., Azkona P. & Donázar J.A. (1998) Density-dependent effects on productivity in the Griffon vulture Gyps fulvus: the role of interference and habitat heterogeneity. Ibis, 140, 6469.
Ferreira S.M., Greaver C., Knight G.A., Knight M.H., Smit I.P.J. & Pienaar D. (2015) Disruption of rhino demography by poachers may lead to population declines in Kruger National Park, South Africa. PLoS ONE, 10(6), e0127783.
García-Ripollés C. & López-López P. (2011) Integrating effects of supplementary feeding, poisoning, pollutant ingestion and wind farms of two vulture species in Spain using a population viability analysis. Journal of Ornithology, 152, 879888.
Green I. (2015) Elephant, 46 vultures and 4 lions killed for muti. The Lowvelder. Http://lowvelder.co.za/299742/knp-poison [accessed 1 March 2016].
Groom R.J., Gandiwa E., Gandiwa P. & van der Westhuizen H.J. (2013) A mass poisoning of white-backed and lappet-faced vultures in Gonarezhou National Park. Honeyguide, 59, 59.
Herholdt J.J. (1997) The status and conservation of vultures in the Mpumalanga Province, South Africa. In Vultures in the 21st Century (eds Boshoff A.F., Anderson M.D. & Borello W.D.), pp. 1320. Vulture Study Group, Johannesburg, South Africa.
IUCN/SSC (2013) Guidelines for Reintroductions and Other Conservation Translocations. Version 1.0. IUCN Species Survival Commission, Gland, Switzerland.
Jackson A.L., Ruxton G.D. & Houston D.C. (2008) The effect of social facilitation on foraging success in vultures: a modelling study. Biology Letters, 4, 311313.
Kane A., Jackson A.L., Monadjem A., Colomer M.A. & Margalida A. (2014) Carrion ecology monitoring for vulture conservation: are vulture restaurants needed to sustain the densest breeding population of the African white-backed vulture? Animal Conservation, 18, 279286.
Kemp A.C. & Kemp M.I. (1975) Observations on the white-backed vulture Gyps africanus in the Kruger National Park, with notes on other avian scavengers. Koedoe, 18, 5168.
Kendall C.J. & Virani M.Z. (2012) Assessing mortality of African vultures using wing tags and GSMGPS transmitters. Journal of Raptor Research, 46, 135140.
Lacy R.C. (1993) VORTEX: a computer simulation model for population viability analysis. Wildlife Research, 20, 4565.
Lacy R.C. & Pollak J.P. (2014) Vortex: A Stochastic Simulation of the Extinction Process. Chicago Zoological Society, Brookfield, USA.
Margalida A., Colomer M.A. & Oro D. (2014) Man-induced activities modify demographic parameters in a long-lived species: effects of poisoning and health policies. Ecological Applications, 24, 436444.
Margalida A., Heredia R., Razin M. & Hernandez M. (2008) Sources of variation in mortality of the bearded vulture Gypaetus barbatus in Europe. Bird Conservation International, 18, 110.
McKean S., Mander M., Diedrichs N., Ntuli L., Mavundla K., Williams V. & Wakelin J. (2013) The impact of traditional use on vultures in South Africa. Vulture News, 65, 1536.
McNutt J.W. & Bradley J. (2014) Report on Kwando (Botswana) vulture poisoning investigation 16 November 2013. Vulture News, 66, 3541.
Mingozzi T. & Estève R. (1997) Analysis of a historical extirpation of the bearded vulture Gypaetus barbatus (L.) in the western Alps (France–Italy): former distribution and causes of extirpation. Biological Conservation, 79, 155171.
Monadjem A., Botha A. & Murn C. (2013) Survival of the African white-backed vulture Gyps africanus in north-eastern South Africa. African Journal of Ecology, 51, 8793.
Mulero-Pázmány M., Stolper R., van Essen L.D., Negro J.J. & Sassen T. (2014) Remotely piloted aircraft systems as a rhinoceros anti-poaching tool in Africa. PLoS ONE, 9(1), e83873.
Mundy P., Butchart D., Ledger J. & Piper S. (1992) The Vultures of Africa. Academic Press, London, UK.
Mundy P.J. (1982) The Comparative Biology of Southern African Vultures. Vulture Study Group, Johannesburg, South Africa.
Murn C. & Botha A. (2016) Assessing the accuracy of plotless density estimators using census counts to refine population estimates of the vultures of Kruger National Park. Ostrich, 87, 241246.
Murn C., Combrink L., Ronaldson G.S., Thompson C. & Botha A. (2013) Population estimates of three vulture species in Kruger National Park, South Africa. Ostrich, 84, 19.
Murn C., Mundy P., Virani M.Z., Borello W.D., Holloway G.J. & Thiollay J.M. (2016) Using Africa's protected area network to estimate the global population of a threatened and declining species: a case study of the Critically Endangered white-headed vulture Trigonoceps occipitalis . Ecology and Evolution, 6, 10921103.
Newton I. (1979) Population Ecology of Raptors. T. & A.D. Poyser, Berkhamsted, UK.
Nikolaus G. (2001) Bird exploitation for traditional medicine in Nigeria. Malimbus, 23, 4555.
O'Donoghue P. & Rutz C. (2016) Real-time anti-poaching tags could help prevent imminent species extinctions. Journal of Applied Ecology, 53, 510.
Ogada D.L. (2014) The power of poison: pesticide poisoning of Africa's wildlife. Annals of the New York Academy of Sciences, 1322, 120.
Ogada D.L., Botha A. & Shaw P. (2016a) Ivory poachers and poison: drivers of Africa's declining vulture populations. Oryx, 50, 593596.
Ogada D.L., Shaw P., Beyers R.L., Buij R., Murn C., Thiollay J.M. et al. (2016b) Another continental vulture crisis: Africa's vultures collapsing toward extinction. Conservation Letters, 9, 8997.
Ogada D.L., Torchin M.E., Kinnaird M.F. & Ezenwa V.O. (2012) Effects of vulture declines on facultative scavengers and potential implications for mammalian disease transmission. Conservation Biology, 26, 453460.
Phipps W.L., Willis S.G., Wolter K. & Naidoo V. (2013) Foraging ranges of immature African white-backed vultures (Gyps africanus) and their use of protected areas in southern Africa. PLoS ONE, 81(1), e52813.
Piper S.E., Boshoff A.F. & Scott H.A. (1999) Modelling survival rates in the Cape griffon Gyps coprotheres, with emphasis on the effects of supplementary feeding. Bird Study, 46(Suppl. 1), S230S238.
Sæther B.-E. & Bakke Ø. (2000) Avian life history variation and contribution of demographic traits to the population growth rate. Ecology, 81, 642653.
Saidu Y. & Buij R. (2013) Traditional medicine trade in vulture parts in northern Nigeria. Vulture News, 65, 414.
SANParks (2016) Media release: Elephant and other wildlife poisoned by poachers in the KNP. South African National Parks, Communications & Marketing Department, Kruger National Park. Https://www.sanparks.org/about/news/?id=56608 [accessed 3 March 2016].
Schaub M., Zink R., Beissmann H., Sarrazin F. & Arlettaz R. (2009) When to end releases in reintroduction programmes: demographic rates and population viability analysis of bearded vultures in the Alps. Journal of Applied Ecology, 46, 92100.
Tarboton W.R. & Allan D.G. (1984) The status and conservation of birds of prey in the Transvaal. Transvaal Museum Monograph, 3, 1115.
Thiollay J.M. (2006) The decline of raptors in West Africa: long-term assessment and the role of protected areas. Ibis, 148, 240254.
van Jaarsveld J. (1986) Poisoned white-backed vultures in the Kruger National Park. Vulture News, 16, 22.
van Jaarsveld J. (1987) Increasing numbers of vultures poisoned in the Kruger National Park. Vulture News, 18, 1821.
Wittemyer G., Daballen D.. & Douglas-Hamilton I. (2013) Comparative demography of an at-risk African elephant population. PLoS ONE, 8(1), e53726.
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Oryx
  • ISSN: 0030-6053
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