Co-occurrence and character convergence in two Neotropical bats
Por:
Verde Arregoitia, Luis Darcy, Hernandez-Canchola, Giovani, Santini, Luca, Schweizer, Manuel, Cabrera-Garrido, Martin Y., Leon-Paniagua, Livia S.
Publicada:
10 oct 2018
Resumen:
When functionally similar species co-occur, they are expected to differ in at least 1 niche axis to avoid competition. In bats, small differences in body size can influence ecology, potentially reducing niche overlap. We used yellow-shouldered bats (genus Sturnira) in Mexico as a model to investigate whether interspecific differences in body size increase when 2 related and ecologically similar species occur in sympatry. We hypothesized that size divergence would take place in sympatry, following known patterns whereby larger bats eat larger fruits and smaller bats forage and roost in more cluttered habitats. We collected data on body mass, forearm length, and skull size from museum specimens to characterize the overall dimensions of these bats. Using linear mixed effect models and permutation tests, we tested for differences between areas where these species occur in sympatry or allopatry, while controlling for the confounding effect of environmental variables and sexual dimorphism. Contrary to our original hypothesis, we detected size convergence in sympatric areas, an uncommon pattern in bats. We found no evidence of character displacement for forearm length and body mass, but an effect of co-occurrence on overall skull size and head length. Convergence in overall skull dimensions may reflect shared environmental pressures and similar food resources, which may not represent a limiting factor. Interspecific differences in forearm length remain constant in sympatry or allopatry. These differences likely preceded the 2 species coming into contact and could have allowed initial and ongoing coexistence by influencing wing properties and flight. We highlight the need for multivariate approaches in the study of character displacement, as selective pressures can act differently on different traits allowing both local adaptation and coexistence. © 2018 American Society of Mammalogists, www.mammalogy.org.
Filiaciones:
Verde Arregoitia, Luis Darcy:
Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia CP, Chile
Univ Austral Chile, Inst Ciencias Ambientales & Evolut, Valdivia 5090000, Chile
Hernandez-Canchola, Giovani:
Museo de Zoología Alfonso L. Herrera, Facultad de Ciencias, UNAM, Mexico City, Mexico
Posgrado en Ciencias Biológicas, UNAM, Mexico City, Mexico
Univ Nacl Autonoma Mexico, Fac Ciencias, Museo Zool Alfonso L Herrera, Mexico City 04510, DF, Mexico
Univ Nacl Autonoma Mexico, Posgrad Ciencias Biol, Mexico City 04510, DF, Mexico
Santini, Luca:
Department of Environmental Science, Institute for Wetland and Water Research, Faculty of Science, Radboud University, Nijmegen, Netherlands
Radboud Univ Nijmegen, Fac Sci, Inst Wetland & Water Res, Dept Environm Sci, POB 9010, NL-6500 GL Nijmegen, Netherlands
Schweizer, Manuel:
Vertebrates Department, Natural History Museum Bern, Bernastrasse, Switzerland
Nat Hist Museum Bern, Vertebrates Dept, Bernastr 15, CH-3005 Bern, Switzerland
Cabrera-Garrido, Martin Y.:
Museo de Zoología Alfonso L. Herrera, Facultad de Ciencias, UNAM, Mexico City, Mexico
Posgrado en Ciencias Biológicas, UNAM, Mexico City, Mexico
Univ Nacl Autonoma Mexico, Fac Ciencias, Museo Zool Alfonso L Herrera, Mexico City 04510, DF, Mexico
Univ Nacl Autonoma Mexico, Posgrad Ciencias Biol, Mexico City 04510, DF, Mexico
Leon-Paniagua, Livia S.:
Museo de Zoología Alfonso L. Herrera, Facultad de Ciencias, UNAM, Mexico City, Mexico
Univ Nacl Autonoma Mexico, Fac Ciencias, Museo Zool Alfonso L Herrera, Mexico City 04510, DF, Mexico
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