naa a22 4500 510780601 CHVBK 20180411083245.0 cr unu---uuuuu 180411e20130601xx s 000 0 eng 10.1007/s11692-012-9206-3 doi (NATIONALLICENCE)springer-10.1007/s11692-012-9206-3 Becoming Different But Staying Alike: Patterns of Sexual Size and Shape Dimorphism in Bills of Hummingbirds [Elektronische Daten] [Chelsea Berns, Dean Adams] Hummingbirds are known for their distinctive patterns of sexual dimorphism, with many species exhibiting sex-related differences in various ecologically-relevant traits, including sex-specific differences in bill shape. It is generally assumed that such patterns are consistent across all hummingbird lineages, yet many taxa remain understudied. In this study we examined patterns of sexual size and sexual shape dimorphism in bills of 32 of 35 species in the monophyletic Mellisugini lineage. We also compared patterns of bill size dimorphism in this group to other hummingbird lineages, using data from 219 hummingbird species. Overall, the presence and degree of sexual size dimorphism was similar across all hummingbird lineages, with the majority of Mellisugini species displaying female-biased sexual size dimorphism, patterns that remain unchanged when analyzed in a phylogenetic context. Surprisingly however, we found that sexual dimorphism in bill shape was nearly absent in the Mellisugini clade, with only 3 of the 32 species examined displaying bill shape dimorphism. Based on observations in other hummingbird lineages, the lack of sexual shape dimorphism in Mellisugini is particularly unusual. We hypothesize that the patterns of sexual size dimorphism observed here may be the consequence of differential selective forces that result from competition for ecological resources. We further propose that an influential mechanism underlying shape dimorphism is competition and niche segregation. Taken together, the evolutionary changes in patterns of sexual shape dimorphism observed in Mellisugini suggest that the evolutionary trends of sexual dimorphism in the Trochilidae are far more dynamic than was previously believed. Springer Science+Business Media New York, 2012 Sexual dimorphism nationallicence Geometric morphometrics nationallicence Sexual size dimorphism nationallicence Sexual shape dimorphism nationallicence Hummingbird nationallicence Mellisugini nationallicence Berns Chelsea Department of Ecology, Evolution and Organismal Biology, Iowa State University, 251 Bessey Hall, 50011, Ames, IA, USA aut Adams Dean Department of Ecology, Evolution and Organismal Biology, Iowa State University, 251 Bessey Hall, 50011, Ames, IA, USA aut Evolutionary Biology Springer US; http://www.springer-ny.com 40/2(2013-06-01), 246-260 0071-3260 40:2<246 2013 40 11692 https://doi.org/10.1007/s11692-012-9206-3 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11692-012-9206-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Berns Chelsea Department of Ecology, Evolution and Organismal Biology, Iowa State University, 251 Bessey Hall, 50011, Ames, IA, USA aut NATIONALLICENCE 700 1- Adams Dean Department of Ecology, Evolution and Organismal Biology, Iowa State University, 251 Bessey Hall, 50011, Ames, IA, USA aut NATIONALLICENCE 773 0- Evolutionary Biology Springer US; http://www.springer-ny.com 40/2(2013-06-01), 246-260 0071-3260 40:2<246 2013 40 11692 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer