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Providing evidence to improve practice

Action: Increase ‘on-the-ground’ protection to reduce unsustainable levels of exploitation Bird Conservation

Key messages

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Supporting evidence from individual studies


A before-and-after study in western Costa Rica (Vaughan et al. 2005) found an increase in a scarlet macaw Ara macao population from 185-225 individuals in 1990-4 to 225-265 in 1997-2003, following an increase in anti-poaching patrols and the confiscation of ladders and tree-climbing equipment (used to remove nestlings from nests) and several other interventions (see ‘Use education programmes and local engagement to reduce pressures on species’, ‘Promote sustainable alternative livelihoods based on species’, ‘Provide artificial nesting sites’ and ‘Guard nests to increase nest success’). In 1990-4 the population had been showing a 4%/year decline. In addition, following the start of intensive anti-poaching activities, the young-to-adult ratio (which is related to recruitment rate) was 9% in 1995-6 (compared to an average of 6% for 1990-2003). However, the intensity of the anti-poaching effort could not be maintained and when it was reduced the ratio fell back to 6%.



A before-and-after study on Selvagem Grande, Madeira, Portugal (Granadeiro et al. 2006), found that the population of Cory’s shearwaters Calonectris diomedea borealis increased from approximately 7,000 pairs in 1980 and only 64 chicks on the island in 1976, to 18,100 breeding pairs in 1995 (a 5% annual increase) following the installation of a permanent warden and stricter de facto protection on the island. Before this, a series of severe harvesting events by Portuguese and Spanish fishermen in 1975-6 had reduced the population from 130,000-150,000 in the early 1900s, despite the de jure protection of the island from 1971. Despite a 13% decrease over 1995-8, the population was estimated at 29,540 pairs in 2005.


Referenced papers

Please cite as:

Williams, D.R., Child, M.F., Dicks, L.V., Ockendon, N., Pople, R.G., Showler, D.A., Walsh, J.C., zu Ermgassen, E.K.H.J. & Sutherland, W.J. (2019) Bird Conservation. Pages 141-290 in: W.J. Sutherland, L.V. Dicks, N. Ockendon, S.O. Petrovan & R.K. Smith (eds) What Works in Conservation 2019. Open Book Publishers, Cambridge, UK.