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| Diniz,Pedro. |
| Sexual dimorphism in birds is often attributed to sexual selection, but another interpretation suggests the evolution of this phenomenon by natural selection. Predation may be an important selective pressure, acting mainly on females. In this study, I tested the latter hypothesis on the coal-crested finch (Charitospiza eucosma Oberholser, 1905) in a neotropical savanna of the Central Brazil (Cerrado). I used capture methods for ascertaining the sex ratio in the population, and focal observations to gather behavioral data. My results show that the sex ratio is skewed toward males (1:1.39). Males were more vigilant, vocalized for longer periods of time, and used higher perches than females. Females foraged more, spent more time on parental care and remained... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Birds; Foraging behavior; Predation risk; Sex ratio; Sexual dimorphism. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702011000200003 |
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| Amo,Luisa; López-Rull,Isabel; Pagán,Iluminada; García,Constantino Macías. |
| BACKGROUND: The detection of predator chemical cues is an important antipredatory behaviour as it allows an early assessment of predation risk without encountering the predator and therefore increases survival. For instance, since chemical cues are often by-products of metabolism, olfaction may gather information not only on the identity but also about the diet of predators in the vicinity. Knowledge of the role of olfaction in the interactions of birds with their environment, in contexts as important as predator avoidance, is still scarce. We conducted two two-choice experiments to explore 1) whether the house finch Carpodacus mexicanus can detect the chemical cues of a marsupial predatory mammal, the common opossum (Didelphis marsupialis), and 2) whether... |
| Tipo: Journal article |
Palavras-chave: Carpodacus mexicanus; Olfaction; Omnivorous predator; Predation risk; Predator diet; Predator chemical cues. |
| Ano: 2015 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2015000100005 |
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| Suárez-Cáceres,Gina Patrícia; Adinolfi,Cristiano; Sánchez,Francisco. |
| ABSTRACT Cities have grown throughout the Andes and we know little about the ecology of those species that tolerate them, limiting our options to do conservation. We applied optimal foraging theory to examine the behavior of the Andean White-eared Opossum (Didelphispernigra), in a suburban area in Bogotá, Colombia. We used the giving-up density technique, which uses the amount of food left in a feeding patch, to evaluate whether the opossum's foraging costs were affected by the height of food from the ground, and the quality and quantity of food. We also evaluated whether the spatial heterogeneity of the study site affected the opossum's foraging. We used an artificial feeding patch to test these ideas. When food was either concentrated and, in less amount... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Andes; Giving-up density; Optimal patch use; Predation risk; Urban ecology. |
| Ano: 2020 |
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-548X2020000300359 |
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