Sexual niche partitioning in two species of New Guinean Pachycephala whistlers. Issue 1 (March 2014)

• Record Type: Journal Article
• Authors: Freeman, Ben
• Is Part Of: Journal of field ornithology. Volume 85:Issue 1(2014)
• Page Start: 23
• Page End: 30
• Publication Date: 2014-03
• Subjects: Birds -- Periodicals; Ornithology -- Periodicals; Ornithologie -- Périodiques; Oiseaux -- Baguage -- Périodiques; Oiseaux -- Périodiques; 598
• DOI: 10.1111/jofo.12046
• Languages: English
• ISSNs: 0273-8570

Abstract

<abstract abstract-type="main"> <title>ABSTRACT</title> <p>Sex differences in foraging behavior have been widely reported in the ornithological literature, but few examples are available from tropical avifaunas. Differences between males and females in foraging behavior have been hypothesized to be a byproduct of sexual size dimorphism or a result of niche partitioning to reduce intersexual competition for food or different reproductive roles. From 2010 to 2013, I used foraging data and mist‐net capture rates from multiple study sites to examine possible sex differences in the foraging behavior of two New Guinean <italic>Pachycephala</italic> whistlers. I found that male Regent (<italic>Pachycephala schlegelii</italic>) and Sclater's (<italic>Pachycephala soror</italic>) whistlers consistently foraged in higher strata than females. It is unlikely that these differences are due to sexual dimorphism because these species exhibit little sexual dimorphism. Sex differences in foraging behavior were consistent across years and study sites and did not appear linked to breeding behavior, supporting the food‐competition hypothesis, but not the reproductive‐roles hypothesis. Male territorial defense often occurs in relatively high strata in <italic>Pachycephala</italic> whistlers, possibly influencing male foraging strata. However, male territorial behavior cannot explain why females predominately forage in lower strata. Instead, intersexual competition for food resources is likely the primary driver of differences in the foraging behavior of male and female Regent and Sclater's whistlers.</p> </abstract>