Resumo

LUEVANO-ESPARZA, Jaime; DELGADILLO-VASQUEZ, Ana María  e  MONTES-ONTIVEROS, Ornar. Artificial nesting structures and reproductive success in the Osprey and the Burrowing Owl during eight reproductive seasons in the estuary La Pinta, Puerto Peñasco, Sonora, Mexico. Huitzil [online]. 2015, vol.16, n.1, pp.9-15. ISSN 1870-7459.

Bird reproduction can be limited by the lack of nesting sites. At La Pinta estuary, Puerto Peñasco, Sonora, two species, the Osprey (Pandion haliaetus), and the Burrowing Owl (Athene cunicularia), had no nesting records in the area. We built seven artificial nesting structures to promote local reproduction, four saguaro shaped metallic posts for the Osprey, and three 60x60x60 cm concrete boxes for the Burrowing Owl. During eight reproductive seasons, between 2006 and 2013, we monitored the nesting structures from observation points 100 m away. Ospreys nested in at least one structure during the full period, except in 2012. In the study we recorded 17 nests with 55 hatching eggs, of which 53 produced fledglings in artificial sahuaros and power line poles. In 2005 a Burrowing Owl pair nested in a box laying seven eggs, and a pair nested in a natural burrow laying six eggs. Five and six chicks hatched, respectively. During the following five seasons owls were absent from the area, coming back in 2012, when we recorded a pair with four hatching eggs. In 2013, we observed five owl pairs, with 24 eggs, and 19 hatchlings, with an average of 4.8 eggs/nest. The nesting alternatives for the ospreys were the power towers and the artificial saguaros, nesting preferably en the artificial saguaros. The borrowing owls had as alternatives natural and man-made cavities, five out of eight pairs chose the natural cavities.

Palavras-chave : birds of prey; Pandion haliaetus; Athene cunicularia.