Ja. Stratford et Pc. Stouffer, Reduced feather growth rates of two common birds inhabiting central Amazonian forest fragments, CONSER BIOL, 15(3), 2001, pp. 721-728
Forest fragmentation may negatively affect populations typically found with
in continuous forest tracts Some effects, such as absence from small fragme
nts, are obvious, but other effects may be subtle and easily overlooked. We
evaluated the hypothesis that forest birds dwelling in fragments, where mi
croclimatic conditions have been shown to be hotter, and drier than in cont
inuous forest, may be in poorer physiological condition than those in the f
orest interior We studied two bird species, the Wedge-billed Woodcreeper (G
lyphorynchus spirurus) and the White-crowned Manakin (Pipra pipra), common
to the fragmented landscape north of Manaus, Brazil We analyzed feather gro
wth rates in Pipra and Glyphorynchus captured in 1-, 10-, and 100-ha forest
fragments and continuous forest. Mean daily feather growth rates of the ou
ter right rectrix of birds captured in fragments were significantly slower
than feather growth rates of birds captured in continuous forest. Based on
recapture data, Wedge-billed Woodcreepers probably grew their feathers in s
ites where they were first captured. White-crowned Manakins, however were h
ighly mobile and were recaptured rarely. Although ute cannot conclusively s
how that fragmentation caused birds to be in poorer physiological condition
, the data indicate that birds in poorer physiological condition were more
likely to be captured in fragments than in continuous forest. Thus our data
suggest that forest fragmentation may have subtle but important effects on
species that are relatively common after landscape alteration.