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Seasonal bird activity in gaps created by selective logging in subtropical cloud forest of NW Argentina (Yungas).
A., ZURITA*,1, BEAUMONT, M.1, LI PUMA, M.1, ZULETA, G.1,2, 1 University of Buenos Aires., Ciudad de Buenos Aires.2 Maimonides University., Ciudad de Buenos Aires., Argentina.
ABSTRACT- During the 2001 summer (breading season: BS) and winter (non breading season: NBS) we evaluated bird's activity (point counts method) and resources abundance (fruits and arthropods) in gaps created by selective logging in Yungas of Argentina. In the BS we sampled 5 recent gaps (< 1 year), 5 old gaps (> 10 years) and 10 interior forest sites; whereas in NBS we sampled 5 recent gaps and 5 interior sites. We classified birds in guilds based on diet and strata use (cluster analysis). During the BS we registered 23 common species (gaps: 17; interior forest: 22). Ground granivores and canopy frugivores-insectivores were more active in forest interior, whereas foliage insectivores were more active in recent gaps and nectarivores and foliage omnivores in old gaps (p<0.05 in all cases; K-W test). The arthropod abundance and herb cover were highest in recent gaps and foliage fruit abundance in old gaps; whereas canopy cover and canopy fruit abundance were highest in the interior forest (p<0.1 in all cases). During the NBS we registered 19 common species (gaps: 18; interior forest: 13), only foliage frugivores-insectivores were more active in gaps (p=0.05), arthropod abundance was similar in both situations and foliage fruit was highest in gaps (p<0.01). From a conservation perspective, the heterogeneous distribution of different successional gaps in a forest matrix might favor foliage and ground insectivores birds (particularly during the BS). Most part of the guilds followed their resource using gaps during the BS and gaps and forest interior during the NBS.
KEY WORDS: treefall gaps, yungas, avian , guilds