Do power lines and protected areas present a catch-22 situation for Cape vultures (Gyps coprotheres)?

PLoS One. 2013 Oct 9;8(10):e76794. doi: 10.1371/journal.pone.0076794. eCollection 2013.

Abstract

Cape vulture Gyps coprotheres populations have declined across their range due to multiple anthropogenic threats. Their susceptibility to fatal collisions with the expanding power line network and the prevalence of carcasses contaminated with illegal poisons and other threats outside protected areas are thought to be the primary drivers of declines in southern Africa. We used GPS-GSM units to track the movements and delineate the home ranges of five adult (mean ±SD minimum convex polygon area = 121,655±90,845 km(2)) and four immature (mean ±SD minimum convex polygon area = 492,300±259,427 km(2)) Cape vultures to investigate the influence of power lines and their use of protected areas. The vultures travelled more than 1,000 km from the capture site and collectively entered five different countries in southern Africa. Their movement patterns and core foraging ranges were closely associated with the spatial distribution of transmission power lines and we present evidence that the construction of power lines has allowed the species to extend its range to areas previously devoid of suitable perches. The distribution of locations of known Cape vulture mortalities caused by interactions with power lines corresponded to the core ranges of the tracked vultures. Although some of the vultures regularly roosted at breeding colonies located inside protected areas the majority of foraging activity took place on unprotected farmland. Their ability to travel vast distances very quickly and the high proportion of time they spend in the vicinity of power lines and outside protected areas make Cape vultures especially vulnerable to negative interactions with the expanding power line network and the full range of threats across the region. Co-ordinated cross-border conservation strategies beyond the protected area network will therefore be necessary to ensure the future survival of threatened vultures in Africa.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Breeding
  • Conservation of Natural Resources*
  • Electric Power Supplies*
  • Falconiformes*
  • Female
  • Geographic Information Systems
  • Homing Behavior
  • Male
  • Risk

Grants and funding

The Mazda Wildlife Fund provided KW and VulPro with a research vehicle. Rand Merchant Bank and Computer Facilities provided additional funding to VulPro. Eskom Holdings Ltd funded the tracking units through VulPro. Mankwe Wildlife Reserve provided additional funding for fieldwork. The Leverhulme Trust funded fieldwork and WLP with a Study Abroad Studentship. WLP received a Vice Chancellor’s bursary from Nottingham Trent University. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.