Abstract

CEYCA, Juan Pablo  and  MELLINK, Eric. Reproductive ecology of Brown Boobies (Sula leucogaster) at Morros El Potosí, Guerrero, Mexico. Rev. Mex. Biodiv. [online]. 2009, vol.80, n.3, pp.793-800. ISSN 2007-8706.

We studied the breeding ecology of Brown Boobies (Sula leucogaster) at Morros El Potosí, Guerrero, between January and June 2006. We determined breeding parameters, foraging habits, and patterns of parental care, and evaluated their effects upon breeding success. Brown Boobies nested during a great part of the year, and exhibited 2 breeding peaks: Fall and Spring. During the later, hatching success was 61%. We estimated 1 300 nests/ha on the slope of the island, and 2 000 nests/ha on the top. We did not record predation, but adverse meteorological conditions caused the loss of eggs and chicks. The longer foraging trips (5.78 ± 0.21 h) and deeper diving (5.52 ± 0.42 m) at Morros El Potosí than at other locations suggested that they required a larger foraging effort here, maybe due to warmer water with less resources. Female Brown Boobies spent more time than males tending nests with eggs, or chicks. There were no differences in parental care of the nest among months, which along with variations in the length of foraging trips among months suggests that there were short-term fluctuations in food availability throughout the study.

Keywords : reproductive success; diving; foraging; parental care.