DOI: 10.5061/dryad.qz612jmhc
title: Sociality and morphology differentiate niches of 13 sympatric Amazonian woodcreepers (Dendrocolaptinae)

description: Woodcreepers (Dendrocolaptinae) represent a remarkably uniform group of
 brownish birds that move by hitching up tree trunks as they forage for
 arthropod prey. Despite these superficial similarities, we were able to
 uniquely differentiate the niches of all 13 species north of Manaus by
 integrating morphological traits (e.g., mass and bill size) with
 behavioral traits (e.g., sociality, stratum use, and foraging maneuvers).
 The 5 ant-following (myrmecophilous) species, with their larger bodies and
 heavier bills, were morphologically distinct from the 7 species that join
 mixed-species flocks. A combination of vertical stratum, mass, and bill
 length further distinguished among mixed-flocking species. Two canopy
 species— the solitary Dendrexetastes rufigula and the mixed-flocking
 Lepidocolaptes albolineatus—consistently foraged at higher strata than
 other species. For the remaining mixed-flocking species, the largest 3
 species differed significantly by mass, whereas the smallest 3 species,
 which overlapped broadly in mass, were uniquely distinguished by bill
 length. The 5 ant-following species differed in their degree of
 specialization on ant swarms, from facultative (Hylexetastes perrotii) to
 obligate (Dendrocincla merula). The ant-followers also showed nearly
 discrete mass distributions that essentially differed by Hutchinsonian
 1:1.3 ratios, which likely allows them to maintain interspecific dominance
 hierarchies at the front of raiding army ant swarms. The behaviors we
 quantified (sociality, vertical strata, and myrmecophily), together with
 morphology (mass and bill size), separated all 13 species. We speculate
 that niche partitioning and competitive exclusion allow each woodcreeper
 to uniquely access invertebrate prey, permitting coexistence and
 contributing to high alpha diversity at our study site.
description: See methods section of paper.
description: Coauthors: Cameron L. Rutt,1,2,d, Karl Mokross,1,2,e Jared D.
 Wolfe,1,2,3,f, Erik I. Johnson,1,2,g Patricia F. Rodrigues,1,2,3,*, and
 Philip C Stouffer1,2 1 School of Renewable Natural
 Resources, Louisiana State University AgCenter and Louisiana State
 University, Baton Rouge, Louisiana, USA 1.65 2 Biological Dynamics of
 Forest Fragments Project, Instituto Nacional de Pesquisas da Amazônia,
 Manaus, Amazonas, Brazil 3 Biodiversity Initiative,
 Houghton, Michigan, USA a Current address: Institute of
 Animal Health and Comparative Medicine, Graham Kerr Building, University
 of Glasgow, Glasgow, UK b Current address: CIBIO-InBIO,
 Research Centre in Biodiversity and Genetic Resources, University of
 Porto, Campus de Vairão, Vairão, Portugal c Current
 address: BIOPOLIS Program in Genomics, Biodiversity and Land Planning,
 CIBIO, Campus de Vairão, 4485-661 Vairão, Portugal
 d Current address: American Bird Conservancy, The Plains,
 Virginia, USA 1.70 e Current address: Sci-Comms Comunicação Visual, R.
 José Manoel Serpa, São Carlos, Brazil f Current
 address: Michigan Technological University, College of Forest Resources
 and Environmental Science, Houghton, Michigan, USA
 g Current address: National Audubon Society, Baton Rouge,
 Louisiana, USA