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Mateos-Gonzalez F.,Behavioural and Evolutionary Ecology Research Unit CSIC | Senar J.C.,Behavioural and Evolutionary Ecology Research Unit CSIC
Animal Behaviour | Year: 2012

Individual behavioural differences, consistent over time and/or across situations, have been included under the term of personality. These behavioural differences have been shown to affect a variety of major ecological traits, all of which have a strong effect on the fitness of the individual. However, the personality of an individual could also have a strong influence on the decisions of other individuals, in situations such as selecting or avoiding a social companion or a mate. Under this scenario, indicators of different personalities would have evolved, but the possible signalling of personality has received little consideration to date. We hypothesized that birds can signal their personality through feather coloration and tested this hypothesis in siskins relating different colour patches to their exploration score. To measure exploration, we presented the siskins with a novel object and calculated how long they took to approach it. We found that siskins with larger black bibs showed shorter approach latencies. This finding supports the idea that plumage coloration traits can provide information about personality traits of the bearer. © 2011 The Association for the Study of Animal Behaviour. Source

Senar J.C.,Behavioural and Evolutionary Ecology Research Unit CSIC | Pascual J.,Behavioural and Evolutionary Ecology Research Unit CSIC
Behavioral Ecology and Sociobiology | Year: 2015

Animals competing for resources follow a general rule for which prior residents usually win contests over intruders. This prior residence effect might arise because animals possess a genetically fixed convention so that ‘residents always win’ (i.e. an uncorrelated asymmetry), because residents have a higher resource holding power (RHP) than intruders or because residents have a higher motivation to defend territories (i.e. pay-off asymmetry). The discrimination between these different hypotheses, though, has proven to be difficult. Eurasian siskins (Spinus spinus) provide us with an adequate opportunity to test for the effect of RHP on the prior residence effect. Siskins show two different strategies while in the wintering grounds: residents remain for several weeks on a given location while transients continuously move and residents are dominant over transients. The black bib area of male siskins signals their RHP. In this study, we compared the black bib area of a large sample of male resident and transient siskins and we found no differences between the two subpopulations. Hence, residence status in this species is not related to black bib size, which is a good proxy for RHP. Our results support the view that asymmetries in RHP are not required to explain the prior residence effect. We discuss the important implications that it has on the evolution of partial migration. © 2015, Springer-Verlag Berlin Heidelberg. Source

Del Val E.,Behavioural and Evolutionary Ecology Research Unit CSIC | Negro J.J.,CSIC - Donana Biological Station | Senar J.C.,Behavioural and Evolutionary Ecology Research Unit CSIC
Bird Study | Year: 2013

Capsule Mediterranean Great Tits showed a marked increase in levels of circulating carotenoids during moult and autumn.Aims To study seasonal variation in plasma carotenoid content during a whole annual cycle for Great Tits Parus major inhabiting a Mediterranean woodland.Methods We used a sample of 71 adult male Great Tits captured in NE Spain during a whole year. Data were organized into four seasons (winter, breeding, moult and autumn). We sampled blood to extract plasma. Carotenoid plasma concentrations were analysed by High-performance liquid chromatography (HPLC).Results Lutein and zeaxanthin content varied seasonally, with a marked increase in levels during moult and autumn. Within the moulting period, levels increased gradually as the season progressed. This pattern differed significantly from that previously described in northern European populations, where high values appear mainly in the breeding season. Carotenoid concentrations (lutein: 1.2 ± 0.25, zeaxanthin: 0.07 ± 0.03μg mL-1) were also lower than in northern Europe.Conclusion Mediterranean Great Tits show a very different pattern of circulating carotenoids and lower levels than northern European populations. The increasing pattern of carotenoid availability found within the moulting period raises the need to control for the effect of sampling date when analysing data on carotenoid concentrations at different times of year. © 2013 British Trust for Ornithology. Source

Pascual J.,Behavioural and Evolutionary Ecology Research Unit CSIC | Senar J.C.,Behavioural and Evolutionary Ecology Research Unit CSIC
Behaviour | Year: 2013

Many investigations have studied the effects of predation risk and competition over vigilance and feeding success, but they have proven to be difficult to discriminate. Moreover, none of the studies that have avoided the confusion has considered all the vigilance variables, food intake rate and time spent in the foraging patch. In this study, we designed an experiment with Eurasian siskins Carduelis spinus foraging on three bird table feeders: one with low predation risk and competition, one with low predation risk and high competition and one with high predation risk and intermediate competition. Birds responded to increasing interference competition by increasing mean scan durations (probably due to the birds having to be vigilant for both other flock members and predators) and maintaining the length of mean inter-scan durations, while they responded to increasing predation risk by reducing mean inter-scan durations (probably in order to detect the predator sooner) while maintaining similar length of mean scan durations. Birds were often ejected from the feeder or departed because of disturbances, so time spent on feeders was reduced both because of competition and predation risk. Pecking rates were affected by competition but not by predation risk. Our results clearly show that birds vigilance strategy while foraging might be very different when they are mainly concerned with scanning for predators or when they primarily monitor competing flock companions. In addition, they stress the importance of recording all the vigilance and feeding variables when studying the effect of ecological factors over the foraging behaviour of birds. © Koninklijke Brill NV, Leiden, The Netherlands. Source

Mateos-Gonzalez F.,Behavioural and Evolutionary Ecology Research Unit CSIC | Quesada J.,Behavioural and Evolutionary Ecology Research Unit CSIC | Quesada J.,Catalan Ornithological Institute | Senar J.C.,Behavioural and Evolutionary Ecology Research Unit CSIC
Biology Letters | Year: 2011

Yellow, red or orange carotenoid-based colorations in male birds are often a signal to prospecting females about body condition, health status and ability to find food. However, this general 'ability to find food' has never been defined. Here we show that more brightly ornamented individuals may also be more efficient when foraging in novel situations. The results highlight the fact that evolution may have provided females tools to evaluate cognitive abilities of the males. © 2011 The Royal Society. Source

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