Conspicuous male coloration impairs survival against avian predators in Aegean wall lizards, Podarcis erhardii.

This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1002/ece3.1650Animal coloration is strikingly diverse in nature. Within-species color variation can arise through local adaptation for camouflage, sexual dimorphism and conspicuous sexual signals, which often have conflicting effects on survival. Here, we tested whether color variation between two island populations of Aegean wall lizards (Podarcis erhardii) is due to sexual dimorphism and differential survival of individuals varying in appearance. On both islands, we measured attack rates by wild avian predators on clay models matching the coloration of real male and female P. erhardii from each island population, modeled to avian predator vision. Avian predator attack rates differed among model treatments, although only on one island. Male-colored models, which were more conspicuous against their experimental backgrounds to avian predators, were accordingly detected and attacked more frequently by birds than less conspicuous female-colored models. This suggests that female coloration has evolved primarily under selection for camouflage, whereas sexually competing males exhibit costly conspicuous coloration. Unexpectedly, there was no difference in avian attack frequency between local and non-local model types. This may have arisen if the models did not resemble lizard coloration with sufficient precision, or if real lizards behaviorally choose backgrounds that improve camouflage. Overall, these results show that sexually dimorphic coloration can affect the risk of predator attacks, indicating that color variation within a species can be caused by interactions between natural and sexual selection. However, more work is needed to determine how these findings depend on the island environment that each population inhabits.This work was supported by a Biotechnology and Biological Sciences Research Council studentship, Magdalene College, Cambridge and the British Herpetological Society (K.L.A.M), and a Biotechnology and Biological Sciences Research Council and David Philips Research Fellowship (grant number BB/G022887/1) to M.S

Liquid Lunch – Vampire Bats Feed On Invasive Feral Pigs And Other Ungulates

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Hábitos alimentares de uma guilda de peixes bentívoros em uma praia arenosa na costa Sudeste do Brasil

The feeding biology of eight species of benthivorous fishes was studied in a sandy shore at Anchieta Island, south-eastern Brazilian coast. The fishes fed mainly on Amphipoda and Mysidacea crustaceans. The diet of the most abundant species, the drum Umbrina coroides, was analyzed in three standard length classes (20-55, 56-90 and 91-135 mm). This sciaenid showed an ontogenetic diet shift from Mysidacea to Amphipoda. The feeding behaviour of the sciaenid U. coroides and the gerreid Eucinostomus gula was recorded while snorkeling. During their foraging both species uncovered small organisms buried in the sand. Notwithstanding general similarities in diet, U. coroides and E. gula presented differences in feeding behaviour and morphology. Two carangid species of the genus Trachinotus differed in diet composition and consumed a larger array of food items than the remaining fish species. Differences in diet and feeding activity between the remaining benthivorous species were noted. These differences possibly reduce overlap in resource use and favour the coexistence of guilds of benthivorous fishes on sandy shores.Os hábitos alimentares de oito espécies de peixes bentívoros foram estudados em uma praia arenosa na Ilha Anchieta, costa Sudeste do Brasil. Os peixes consumiram principalmente crustáceos das ordens Amphipoda e Mysidacea. A dieta da espécie mais abundante, o sciaenídeo Umbrina coroides, foi analisada em três classes de comprimento-padrão (20-55, 56-90 e 91-135 mm). Este sciaenídeo apresentou uma variação ontogenética na dieta, a qual variou de Mysidacea para Amphipoda. O comportamento alimentar do sciaenídeo U. coroides e do gerrídeo Eucinostomus gula foi estudado com uso de mergulho livre. Ao forragear, ambas as espécies desenterraram pequenos organismos enterrados na areia. Apesar das semelhanças gerais na dieta, U. coroides e E. gula apresentaram diferenças quanto ao comportamento alimentar e morfologia. Duas espécies de carangídeos do gênero Trachinotus diferiram quanto à composição da dieta e consumiram variedade maior de itens alimentares que as outras espécies de peixes estudadas. Diferenças de dieta e atividade alimentar entre as outras espécies bentívoras foram registradas. Estas diferenças possivelmente reduzem a sobreposição na utilização dos recursos alimentares, favorecendo a coexistência de guildas de peixes bentívoros em praias arenosas.511518Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq