Journal ArticleDOI
Ecological release in lizard assemblages of neotropical savannas.
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TLDR
The results indicate that the ecological release (density compensation) hypothesis is not supported: lizard species are not more abundant in isolated areas than in nonisolated areas, and increases in niche breadth for some species indicate that ecological release occurs as well.Abstract:
We compare lizard assemblages of Cerrado and Amazonian savannas to test the ecological release hypothesis, which predicts that niche dimensions and abundance should be greater in species inhabiting isolated habitat patches with low species richness (Amazonian savannas and isolated Cerrado patches) when compared with nonisolated areas in central Cerrado with greater species richness. We calculated microhabitat and diet niche breadths with data from 14 isolated Cerrado patches and Amazon savanna areas and six central Cerrado populations. Morphological data were compared using average Euclidean distances, and lizard abundance was estimated using the number of lizards captured in pitfall traps over an extended time period. We found no evidence of ecological release with respect to microhabitat use, suggesting that historical factors are better microhabitat predictors than ecological factors. However, data from individual stomachs indicate that ecological release occurs in these areas for one species (Tropidurus) but not others (Ameiva ameiva, Anolis, Cnemidophorus, and Micrablepharus), suggesting that evolutionary lineages respond differently to environmental pressures, with tropidurids being more affected by ecological factors than polychrotids, teiids, and gymnophthalmids. We found no evidence that ecological release occurs in these areas using morphological data. Based on abundance data, our results indicate that the ecological release (density compensation) hypothesis is not supported: lizard species are not more abundant in isolated areas than in nonisolated areas. The ecology of species is highly conservative, varying little from assemblage to assemblage. Nevertheless, increases in niche breadth for some species indicate that ecological release occurs as well.read more
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Niche Expansion and the Niche Variation Hypothesis: Does the Degree of Individual Variation Increase in Depauperate Assemblages?
TL;DR: Whether populations with larger niche breadth have a higher degree of diet variation and whether populations from depauperate lizard assemblages differ in dietary resource use with respect to variation within and/or among individuals and sexual dimorphism is tested.
Phylogeny and Ecology Determine Morphological Structure in a Snake Assemblage in the Central
Frederico Gustavo Rodrigues França,Daniel Oliveira Mesquita,Cristiano Nogueira,Alexandre F. B. Araiijo +3 more
TL;DR: In this paper, 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.
Journal ArticleDOI
Phylogeny and Ecology Determine Morphological Structure in a Snake Assemblage in the Central Brazilian Cerrado
Frederico Gustavo Rodrigues França,Daniel Oliveira Mesquita,Cristiano Nogueira,Alexandre F. B. de Araújo +3 more
TL;DR: It is concluded that phylogeny is the most important factor determining structure of this Neotropical assemblage of snakes and a strong ecological component characterizes a peculiar snake fauna in the Cerrado of Distrito Federal, Brazil.
Journal ArticleDOI
Lizards on newly created islands independently and rapidly adapt in morphology and diet
Mariana Eloy de Amorim,Mariana Eloy de Amorim,Thomas W. Schoener,Guilherme Ramalho Chagas Cataldi Santoro,Anna Carolina Ramalho Lins,Jonah Piovia-Scott,Reuber Albuquerque Brandão +6 more
TL;DR: Differences in morphology and diet of the termite-eating gecko Gymnodactylus amarali between five such newly created islands and five nearby mainland sites located in the Brazilian Cerrado, a biodiversity hotspot are reported.
Journal ArticleDOI
Biodiversity, threats and conservation challenges in the Cerrado of Amapá, an Amazonian savanna.
Karen Mustin,William Douglas de Carvalho,Renato R. Hilário,Salustiano V. Costa-Neto,Claudia Regina Silva,Ivan M. Vasconcelos,Isai Jorge de Castro,Vivianne Eilers,Érico E. Kauano,Raimundo Nonato Gomes Mendes-Júnior,Cláudia Funi,Philip M. Fearnside,José Maria Cardoso da Silva,Ana Margarida Castro Euler,José Julio de Toledo +14 more
TL;DR: In this paper, the status of knowledge concerning the biodiversity of the Cerrado of Amapa, its conservation status, and the main threats to the conservation of this Amazonian savanna are presented.
References
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TL;DR: The notion of coevolutionary shaping of competitors' niches has little support at present, and theory and evidence suggest that it is probable only in low diversity communities.
Journal ArticleDOI
The cerrado vegetation of Brazil
TL;DR: Cerrado as a vegetational province has been identified as one of the most important regions in the world in terms of vegetation diversity and diversity of trees and shrubs as discussed by the authors.