Nesting success of understory forest birds in central Panama

• DOI: 10.1034/j.1600-048x.2000.310207.x
• Publication Date: 2003-11-02T16:05:06Z
• Authors: W. Douglas Robinson; Tara Rodden Robinson; Scott K. Robinson; Jeffrey D. Brawn
• Keywords: Panama; Understory; Fledge; Temperate rainforest; Temperate forest; Life History Theory

Greater nest predation in tropical than temperate birds has been hypothesized to be a primary selective force generating latitudinal differences avian life history traits. Few extensive data sets, however, have available from forests compare with forests. To increase the amount of empirical information for addressing issues related evolution traits birds, we measured nesting success understory lowland forest central Panama. We found and monitored fates 696 nests 71 species over two breeding seasons. Daily rates ten which obtained largest samples ranged 1.6 8.3%, equivalent loss 43 92% nests. These values overlapped extensively range daily experienced by ecologically similar North America. Proportion fledging young, estimated Mayfield method, was significantly lower (range: 8 57%) (27 60%) species. Nesting Panama varied among years, being greater 1996 1997. In 1996, that fragments midwestern When compared large, contiguous tracts America, consistently approximately 23%. conclude may poor most seasons, but also punctuated occasional years relatively exceptional success, possibility heretofore unappreciated because general paucity tropics. Furthermore, our results indicate substantial variation levels species, almost no clutch size. Such large interspecific variation, as well potentially annual does not support hypothesis uniformly low select small sizes.