BRAZILIAN ARCHIVES OF BIOLOGY AND TECHNOLOGY
Diet and Prey Availability of Terrestrial Insectivorous Birds
Prone to Extinction in Amazonian Forest Fragments
Luiz Augusto Macedo Mestre1,2,3* , Mario Cohn-Haft4 and Manoel Martins Dias2
https://www.scielo.br/j/babt/a/SV6MqBm345wVDJPLycktBHt/?lang=en&format=pdf
Vol.53, n. 6: pp.1371-1381, November-December 2010
ISSN 1516-8913 Printed in Brazil
BRAZILIAN ARCHIVES OF BIOLOGY AND TECHNOLOGY
Diet and Prey Availability of Terrestrial Insectivorous Birds
Prone to Extinction in Amazonian Forest Fragments
Luiz Augusto Macedo Mestre1,2,3* , Mario Cohn-Haft4 and Manoel Martins Dias2
ABSTRACT
This study compared niche breath, prey size, and diet variability in two pairs of sympatric species of terrestrial
insectivorous birds, each pair containing one species that can persist in small forest fragments and one that does
not. The pairs were Myrmeciza ferruginea and Sclerurus rufigularis; and Formicarius colma and F. analis,
respectively. The prey availability in forest fragments was also sampled and compared to the availability in
continuous forests. Niche breath indices did not differ between pair members, but diet variability differed in the
opposite direction from that hypothesized. Although the two bird species most vulnerable to fragmentation fed on
larger prey than less vulnerable species, prey availability, including that based on prey size did not differ among
fragmented versus continuous forest sites. Thus, diet per se appeared not to be an important cause of extinctionproneness
in these species. The simplest explanation proposed, that vulnerability to fragmentation was directly
related to territory size, requires testing. However, it was consistent with observations that the bird species feeding
on larger prey also need larger territories.