Fear is the mother of invention: anuran embryos exposed to predator cues alter life-history traits, post-hatching behaviour and neuronal activity patterns.

Neurophysiological modifications associated to phenotypic plasticity in response to predators are largely unexplored, and there is a gap of knowledge on how the information encoded in predator cues is processed by prey sensory systems. To explore these issues, we exposed Rana dalmatina embryos to dragonfly chemical cues (kairomones) up to hatching. At different times after hatching (up to 40 days), we recorded morphology and anti-predator behaviour of tadpoles from control and kairomone-treated embryo groups as well as their neural olfactory responses, by recording the activity of their mitral neurons before and after exposure to a kairomone solution.

Sperm traits negatively covary with size and asymmetry of a secondary sexual trait in a freshwater crayfish.

In species where females mate promiscuously, the reproductive success of males depends both on their ability to acquire mates (pre-copulatory sexual selection) and ability of their ejaculates to outcompete those of other males (post-copulatory sexual selection). Sperm competition theory predicts a negative relationship between investment in body traits favouring mate acquisition (secondary sexual characters, SSCs) and investment in ejaculate size or quality, due to the inherent costs of sperm production. In contrast, the phenotype-linked fertility hypothesis posits that male fertilizing efficiency is reliably reflected by the phenotypic expression of male SSCs, allowing females to obtain direct benefits by selecting more ornamented males as copulation partners.

Sex-, morph- and size-specific susceptibility to stress measured by haematological variables in captive common wall lizard Podarcis muralis.

In polymorphic species of animals, colour morphs may show alternative physiological properties, and hence evolve or be maintained as an indirect response to selection exerted on these physiological attributes. In this study, we investigated if different colour morphs (white, red and yellow) of the polymorphic common wall lizard differed in their physiological responses to a long-term stress by determining variation between capture and release in leukocytes profiles, haemoparasite loads and body condition of male and females maintained in captivity throughout the breeding season. We found that most blood parameters of lizards varied significantly following captivity, and this variation was sex-, morph- and size-dependent.

Global changes and animal phenotypic responses: melanin-based plumage redness of scops owls increased with temperature and rainfall during the last century.

The ecological effects of global climate changes include shifts of species' distribution and changes in migration strategies and phenotype. Colour polymorphism, which can be envisaged as a species' evolutionary response to alternating conditions or to a wide range of habitats, may be affected by climate changes as well. The scops owl (Otus scops) shows two main colour morphs, dark- and pale-reddish, as well as intermediate morphs.

Male-male combats in a polymorphic lizard: residency and size, but not color, affect fighting rules and contest outcome.

Theoretical models predict that the outcome of dyadic agonistic encounters between males is influenced by resource-holding potential, resource value, and intrinsic aggressiveness of contestants. Moreover, in territorial disputes residents enjoy a further obvious competitive advantage from the residency itself, owing to the intimate familiarity with their territory. Costs of physical combats are, however, dramatically high in many instances.

Sexual dimorphism in digit length ratios in two lizard species.

Sexual dimorphism in digit length ratios has been reported for humans, a few other mammals, and two bird species. This dimorphism is thought to arise via an interaction between the prenatal exposure of the embryo to sex hormones and the Hox genes, which are highly conserved among vertebrates and control the development of both the appendices, including fingers and toes, and the urogenital system. In this study, we report on sexual dimorphism in 2D:3D, 2D:4D, and 3D:4D contralateral ratios of the forelimbs in two species of oviparous lizards, the common wall lizard (Podarcis muralis) and the tree skink (Mabuya planifrons), as measured on museum specimens.

Female freshwater crayfish adjust egg and clutch size in relation to multiple male traits.

Females may invest more in reproduction if they acquire mates of high phenotypic quality, because offspring sired by preferred partners may be fitter than offspring sired by non-preferred ones. In this study, we tested the differential maternal allocation hypothesis in the freshwater crayfish, Austropotamobius italicus, by means of a pairing experiment aimed at evaluating the effects of specific male traits (body size, chelae size and chelae asymmetry) on female primary reproductive effort. Our results showed that females laid larger but fewer eggs for relatively small-sized, large-clawed males, and smaller but more numerous eggs for relatively large-sized, small-clawed males.

Effects of elevated egg corticosterone levels on behavior, growth, and immunity of yellow-legged gull (Larus michahellis) chicks.

Eggs of vertebrates contain steroid hormones of maternal origin that may influence offspring performance. Recently, it has been shown that glucocorticoids, which are the main hormones mediating the stress response in vertebrates, are transmitted from the mother to the egg in birds. In addition, mothers with experimentally elevated corticosterone levels lay eggs with larger concentrations of the hormone, which produce slow growing offspring with high activity of the hypothalamo-adrenal axis under acute stress.

Larynx morphology and sound production in three species of Testudinidae.

Although the ability to vocalize is widespread among tortoises, the mechanisms of sound production in chelonians remain undescribed. In this study, we analyze the morphology and histology of the larynx of three species of Testudinidae (Testudo hermanni, T. graeca, and T.