Breeding phenology and nesting habitat characterisation of the San Andres Vireo ( Vireo caribaeus)

Abstract

We describe the breeding phenology and nesting habitat characteristics of San Andres Vireo Vireo caribaeus for the breeding season of 2004. Nest monitoring of colour marked individuals took place in three major vegetation types (dry scrubland, mangrove forest and dense forest) on San Andres Island, Colombia. In all of them, vegetation structure variables were measured and compared using principal components analysis. A courting song was recorded and its sonograms are presented here. Nineteen nests were monitored between January and June, of which 80% were found in dry scrubland, 10% in mangrove forest and 10% in dense forest. Nesting stages were found to be similar in length to those known for other vireos. Nest construction took 6 ± 0.87 days (mean ± SD), clutch size was 2 ± 1 eggs (mean ± SD), incubation took 17 ± 2.47 days (mean ± SD), and nestling period was 9 ± 1.57 days (mean ± SD). Fourteen nestlings fledged from successful nests (53%) and post fledging care was sustained for 28 ± 4.17 days (mean ± SD). Vireo nests were found in sheltered dry areas, characterized by a thick cover of dead leaves on the ground (≤ 60%) and a low canopy height (mean = 5 m) but providing 60% cover over the nest. Nest trees were healthy plants and 75% of the nests hung from east-facing forked branches at a height of 0.73–2.0 m. Nesting trees were typically surrounded by 3-5 species of fleshy fruit plants fed to chicks. Conservation of the vireo would benefit from maintenance of traditional land use practices in dry scrubland on the island and protection or special management of some areas of this habitat should be considered.