Phylogeny and Ecology Determine Morphological Structure in a Snake Assemblage in the Central Brazilian Cerrado
To investigate the role of ecological and historical factors in the organization of communities, we describe the ecomorphological structure of an assemblage of snakes (61 species in six families) in the Cerrado (a savanna-like grassland) of Distrito Federal, Brazil. These snakes vary in habits, with some being fossorial, cryptozoic, terrestrial, semi-aquatic, or arboreal. Periods of activity also vary. A multivariate analysis identified distinct morphological groups associated with patterns of resource use. We report higher niche diversification compared to snakes in the Caatinga (a semi-arid region in northeastern Brazil), with fossorial and cryptozoic species occupying morphological space that is not occupied in the Caatinga. Monte Carlo permutations from canonical phylogenetic ordination revealed a significant phylogenetic effect on morphology for Colubridae, Colubrinae, Viperidae, Elapidae, and Boidae indicating that morphological divergence occurred in the distant past. We conclude that phylogeny is the most important factor determining structure of this Neotropical assemblage. Nevertheless, our results also suggest a strong ecological component characterizes a peculiar snake fauna.Abstract
Individual groups used in canonical phylogenetic ordination for microhabitat and diet data. Phylogeny based on Burbrink (2005); Cadle and Greene (1993); Dixon (1985); Ferrarezzi (1993, 1994); Ferrarezzi et al. (2005); Greene (1997); Lawson et al. (2005); Lobo and Scrocchi (1994); Martins et al. (2002); Vidal et al. (2000); Wüster et al. (2002); and Zaher (1999).
Plot of factor scores from principal components for 60 species of Distrito Federal snakes. The PCA follows the model used by Vitt and Vangilder (1983). The species are: 1–Apostolepis assimilis; 2–A. albicollaris ; 3–A. flavotorquata; 4–Atractus pantostictus; 5–Apostolepis ammodytes; 6–Boa constrictor; 7–Bothrops itapetiningae; 8–Boiruna maculata; 9–Bothrops moojeni; 10–Bothrops neuwiedi; 11–Crotalus durissus; 12–Chironius exoletus; 13–C. flavolineatus; 14–Clelia plumbea; 15–Chironius quadricarinatus; 16–Clelia quimi; 17–Drymoluber brazili; 18–Drymarchon corais; 19–Erythrolamprus aesculapii; 20–Epicrates cenchria; 21–Gomesophis brasiliensis; 22–Helicops angulatus; 23–H. leopardinus; 24–H. modestus; 25–Liophis almadensis; 26–Leptodeira annulata; 27–Leptotyphlops fuliginosus; 28–Liophis maryellenae; 29–Liophis meridionalis; 30–Lystrophis nattereri; 31–Liophis paucidens; 32–Liophis poecilogyrus; 33–Liophis reginae; 34–Liotyphlops ternetzii; 35–Mastigodryas bifossatus; 36–Micrurus frontalis; 37–M. lemniscatus; 38–Oxybelis aeneus; 39–Oxyrhopus guibei; 40–O. rhombifer; 41–O. trigeminus; 42–Philodryas aestiva; 43–Pseudablabes agassizii; 44–Phimophis guerini; 45–Phalotris nasutus; 46–Philodryas nattereri; 47–Pseudoboa nigra; 48–Philodryas olfersii; 49–P. patagoniensis; 50–P. psammophideus; 51–Rhachidelus brazili; 52–Sibynomorphus mikanii; 53–Spilotes pullatus; 54–Simophis rhinostoma; 55–Thamnodynastes hypoconia; 56–Tantilla melanocephala; 57–Echinantera occipitalis; 58–Thamnodynastes rutilus; 59–Waglerophis merremii; 60–Xenopholis undulatus.
Plot of factor scores from principal components for 60 species of Distrito Federal snakes. The PCA used residuals of the regression between morphological variables and the estimating variable for body size. For snake species, see legend of Figure 2.
Contributor Notes
Section Editor: T. W. Reeder.
1Programa de Pós-Graduação em Ecologia, Departamento de Ecologia, Instituto de Ciências Biológicas, Universidade de Brasília, 70910-900, Brasília, DF, Brazil, e-mail: fgrf@unb.br Send reprint requests to this address.
2Curso de Ciências Biológicas, Universidade Católica de Brasília, or Departamento de Zoologia, Instituto de Ciências Biológicas, Universidade de Brasília, 70910-900, Brasília, DF, Brazil, e-mail: danmesq@unb.br.
3Instituto de Biociências, Caixa Postal 11461, Universidade de São Paulo, 05422-970, São Paulo, SP, Brazil.
4Departamento de Biologia Animal, Universidade Federal Rural do Rio de Janeiro, 23890-000, Seropédica, RJ, Brazil, e-mail: araújo@ufrrj.br.