Nesting habitat and density, nest characteristics, home ranges and group sizes of the Rufous-fronted Thornbird (Phacellodomus rufifrons) in Central Brazil

Abstract

Rufous-fronted Thornbird (Phacellodomus rufifrons) reproduction has been studied under a few environmental conditions but might show some variations among regions throughout its wide geographic distribution. We describe here nesting habitat and density, nest characteristics, home ranges and group sizes of Rufous-fronted Thornbird in a Cerrado reserve in central Brazil. We found 131 nests in 2003, 2004, and 2011, and studied four groups inside a 100-ha grid. Nests were found only incerrado típicoandcerrado ralobut changed in abundance and density over the years, with a higher density in 2004 (0.37 nest/ha) than in 2011 (0.23 nest/ha). Nests were built 3.2 ± 1.0 m above the ground at 6.3 ± 0.2 m high trees of 31 species, but mostly ofQualeaspp. Nests were 0.66 ± 0.27 m high and 0.44 ± 0.11 m wide. Home ranges had an average of 3.1 ± 0.3 ha, used by family groups of 4.6 ± 0.5 individuals. This study consolidates the findings of previous ones, but also highlights differences in habitat use, nest size, and nesting tree among regions or study sites, and changes in density among years, stressing the importance of studying the reproductive biology of the same bird species under different environmental conditions since different conditions might affect reproductive traits, such as reproductive investment and timing.