Ecology of a Cerrado Lizard Assemblage in the Jalapão Region of Brazil
We examined the relative roles of contemporary (species interactions) and historical factors (phylogeny) in structuring a lizard assemblage (14 species) from one of the last remaining large expanses of undisturbed Cerrado in Brazil. Niche breadth for microhabitat was low for all species in the assemblage, and microhabitat niche overlaps varied from none to almost complete and appeared associated with phylogenetic similarity. Mean microhabitat and diet overlaps among lizard species did not differ statistically from random, based on a pseudocommunity analysis, indicating a negligible role of contemporary factors in assemblage structure. Prey overlaps were highest within Gymnophthalmidae and Teiidae. A cluster analysis of principal component scores of morphometric variables revealed groups corresponding to lizard families, suggesting a strong association between morphology and phylogeny. Similarities among closely related species in microhabitat use, diel activity, and diet breadth, based on cladogram inspection, suggested that phylogeny might affect assemblage structure. However, a Canonical Phylogenetic Ordination (CPO) analysis revealed no significant phylogenetic effects on lizard microhabitat use or diet composition. We suggest that under-representation of species in major clades (low taxon sampling) renders it difficult to detect potential historical and ecological effects on assemblage structure.Abstract
Individual groups used in canonical phylogenetic ordination for microhabitat and diet data. Phylogeny based on Estes et al. (1988).
Frequency distribution of individuals according to microhabitat categories for Jalapão lizards. Sample sizes are indicated at the top of the bars.
Plot of the average per species of the first two principal components derived from size-free morphological data for Jalapão lizards.
Phylogeny of Jalapão lizards showing the topology of ecological characteristics. Abbreviations for habitat are: C = Cerrado, GF = Gallery forest, R = rocky field. Abbreviations for microhabitat are: A = arboreal, OG = open ground, B = bushes, LD = litter-dwelling, S = saxicolous, TN = termite nest. Abbreviations for activity are: D = diurnal, N = nocturnal, CN = crepuscular/nocturnal. Note: general microhabitat categories are based on data from this work and from Vieira et al. (2000), Vitt (1991), Vitt and Caldwell (1993), Vanzolini et al. (1980), and Ávila-Pires (1995).
Contributor Notes
(DOM, GRC, FGRF) Departamento de Zoologia, Instituto de Biologia, Universidade de Brasi´lia, 70910-900 Brasi´lia, Distrito Federal, Brazil ; And (LJV) Sam Noble Oklahoma Museum of Natural History and Zoology Department, University of Oklahoma, 2401 Chautauqua Avenue, Norman, Oklahoma 73072 . E-mail: (DOM) danmesq@unb.br; (GRC) grcolli@unb.br; and (LJV) vitt@ou.edu. Send reprint requests to DOM.