Bird communities in two oceanic island forests fragmented by roads on Tenerife, Canary Islands
Fecha
2008Resumen
Although most studies on road effects on birds have been conducted on continental grounds, road fragmentation on oceanic
islands is often heavier. We assessed variation in bird communities near (≤25 m) and far (>100 m) from forest roads dividing
laurel and pine forests on Tenerife, Canary Islands. Line transects were used as the census technique. We compared
community structure and species responses between both forests, and among forest interior and edges of paved and
unpaved roads. We analysed richness and diversity of species in these different situations, and tested for significance in
bird community descriptors and species abundance responses to road proximity. The bird community of the laurel forest
showed significantly higher average population density, richness, diversity and evenness than that of the pine forest. None
of the two forests showed significant differences in community descriptors between edge and interior, except for a higher
evenness along unpaved roads in the laurel forest. However, the bird community showed more overall abundances, richness
and diversity on unpaved than on asphalt road edges in laurel forest. Excepting two passerines (Turdus merula in laurel
forest and Phylloscopus canariensis in pine forest), all species had similar abundances on road edges and forest interior
regardless of forest type. Most species might be regarded as forest generalists. Changes detected between edge and interior
on road-fragmented forests were, overall, small at the bird community level. Managers should consider the effects of road
edge and road type on the more sensitive species in present and future road planning.