Feeding ecology of the pygmy gecko Coleodactylus natalensis (Squamata: Sphaerodactylidae) in the Brazilian Atlantic Forest

Lisboa, Carolina Maria Cardoso Aires; Sales, Raul Fernandes Dantas; Freire, Eliza María Xavier

doi:10.1590/s1984-46702012000400002

Cited by 2 publications

(1 citation statement)

References 25 publications

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“…Although many studies describe diet (Bustard ; Floyd & Jenssen ; Sales & Freire ), few estimate prey availability as well (Dubas & Bull ; Griffiths & Christian ; Manicom & Schwarzkopf ; Lisboa et al . ). To estimate prey selectivity, a description of the diet must be compared with some measure of prey availability (Diaz & Carrascal ).…”

Section: Introductionmentioning

confidence: 97%

Abundance, diet and prey selection of arboreal lizards in a grazed tropical woodland

et al. 2017

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The diet of predators is a critical determinant of their ecological effects. Small vertebrate predators of invertebrates are often characterized as diet generalists based on diet descriptions, but few studies examine prey availability to determine whether prey choice occurs. We studied the prey availability in relation to the diet of two common and abundant, but understudied small vertebrates: Gehyra dubia, an arboreal nocturnal gecko, and Cryptoblepharus australis, an arboreal diurnal skink. We sampled lizards in two major woodland habitat types, Reid River box (Eucalyptus brownii) and Silver-leaf ironbark (Eucalyptus melanophloia) and among four cattle grazing regimes (ranging from moderateheavy stocking). Cryptoblepharus australis were more abundant in the Silver-leaf ironbark habitat, but there was no effect of grazing regime on their abundance. In contrast, G. dubia did not differ significantly in abundance in relation to habitat type, but were more abundant in paddocks with heavier stocking rates. We quantified invertebrate prey available to lizards in these habitats using defined-area searches and light trapping. Invertebrate community composition did not differ significantly between the habitat types or among the four grazing regimes. Although G. dubia and C. australis both occupied the same microhabitats, they were temporally segregated based on their activity times. While both species are apparently habitat generalists, we found that G. dubia and C. australis are selective in their diets. Only half of the invertebrate groups available in the environment occurred in the diets of either lizard species. Both species positively selected Coleoptera (beetles), Araneae (spiders), and Scorpiones (scorpions), and they exhibited high dietary niche overlap (O = 0.97). We suggest the increased availability of the top three preferred prey groups (beetles, spiders, and scorpions) may contribute to the high abundances of G. dubia in heavily grazed areas.

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Section: Introductionmentioning

confidence: 97%

Abundance, diet and prey selection of arboreal lizards in a grazed tropical woodland

et al. 2017

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Dietary niche variation and its relationship to lizard population density

Novosolov

Rodda

Gainsbury

et al. 2017

Journal of Animal Ecology

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Abstract1. Insular species are predicted to broaden their niches, in response to having fewer competitors. They can thus exploit a greater proportion of the resource spectrum.In turn, broader niches are hypothesized to facilitate (or be a consequence of) increased population densities.2. We tested whether insular lizards have broader dietary niches than mainland species, how it relates to competitor and predator richness, and the nature of the relationship between population density and dietary niche breadth.3. We collected population density and dietary niche breadth data for 36 insular and 59 mainland lizard species, and estimated competitor and predator richness at the localities where diet data were collected. We estimated dietary niche shift by comparing island species to their mainland relatives. We controlled for phylogenetic relatedness, body mass and the size of the plots over which densities were estimated.4. We found that island and mainland species had similar niche breadths. Dietary niche breadth was unrelated to competitor and predator richness, on both islands and the mainland. Population density was unrelated to dietary niche breadth across island and mainland populations. 5. Our results indicate that dietary generalism is not an effective way of increasing population density nor is it result of lower competitive pressure. A lower variety of resources on islands may prevent insular animals from increasing their niche breadths even in the face of few competitors. K E Y W O R D Sdiet, lizards, niche breadth, niche variation hypothesis, population density

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Feeding ecology of the pygmy gecko Coleodactylus natalensis (Squamata: Sphaerodactylidae) in the Brazilian Atlantic Forest

Cited by 2 publications

References 25 publications

Abundance, diet and prey selection of arboreal lizards in a grazed tropical woodland

Abundance, diet and prey selection of arboreal lizards in a grazed tropical woodland

Dietary niche variation and its relationship to lizard population density

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