Catry, P., Dias, M.P., Catry, T., Pedro, P., Tenreiro, P. & Menezes, D. (2015) Bulwer’s petrels breeding numbers on the Desertas Islands (Madeira): improved estimates indicate the NE Atlantic population to be much larger than previously thought. Airo, 23, 10-14.
NON-cE3c affiliatedCurrent estimates of the European breeding population of Bulwer’s petrel Bulweria bulwerii stand at 7000-9000 pairs, and the literature describes the Desertas Islands population as the second largest in the region, with 1500 pairs. Using a capture-mark-recapture method on a patch of 3.3 ha of good quality habitat on Deserta Grande, and after having handled a total of 1839 individuals in two years, we estimated the presence of 8389 individuals (95% conf. limits: 6824 – 10,309). Correcting for the number of likely immature birds and taking into account overall habitat availability, we tentatively estimate the breeding population at 45,000 pairs on the Desertas Islands group. Although this estimate contains large sources of uncertainty, it is clear that the Desertas Islands population, and perhaps the whole European population, is one order of magnitude larger than previously thought.
Maria Ana Dias Conservation in Socio-Ecological Systems - CSES
