Search results for "guttata"

Personality affects zebra finch feeding success in a producer-scrounger game.

2011

7 pages; International audience; Recent evidence strongly suggests that natural selection can favour the evolution of consistent individual differences in behaviour ('personalities'). Indeed, personality shows heritable variation and has been linked to fitness in many species. However, the fitness effects of personality are highly variable within and between species. Furthermore, the nature of the causal influence of personality on an organism's fitness remains unclear so far. Competition has been proposed as a factor modulating this relationship. Thus, personality has been found to affect individual success in competition by interference in a few species, but its influence in scramble comp…

Heterogeneity of host-parasite relationships : ecological and evolution significance

2005

Although parasites have been studied for a long time, the major knowledge concern parasite which have medical or veterinary interest. Whereas they are omnipresent in the nature, the role of parasite infections on natural populations is poorly understood. One of the aim of this work was to study the pathogenicity of two groups of parasites (ticks and Haemosporidae) among natural populations of blackbirds. The study revealed that both parasites are associated with body condition and immune response. However, the study of an urban blackbird population did not confirm the effect of Haemosporidae on the survey and on the population dynamic.The impact of spatial pattern on the relation between ho…

A stochastic model of seed dispersal pattern to assess seed predation by ants in annual dry grasslands

2005

A combined field experiment and modelling approach has been used to provide evidence that ants may be responsible for an observed lower patchiness and higher plant diversity in the neighbourhood of ant nests, within Mediterranean dry grasslands belonging to the phytosociological class Tuberarietea guttatae. The hypothesis was that seeds occurring in clumps may have an higher probability to be harvested than seeds having a scattered distribution. In order to test this hypothesis, four analysis steps have been performed. First, the seed productivity and dispersal pattern was recorded for four plant species found, either more abundant beside the ant nests (Tuberaria guttata, Euphorbia exigua) …

Environmental stress affects the expression of a carotenoid-based sexual trait in male zebra finches.

2007

SUMMARY Abiotic factors including thermal stress are suggested to exert constrains on sexual ornaments through trade-offs between sexual displays and physiological functions related to self-maintenance. Given the health properties of carotenoid pigments, carotenoid-based ornaments offer a relevant context in which to investigate the effect of environmental stress, such as ambient temperature, on the production and maintenance of secondary sexual traits and, also, to explore the proximate mechanisms shaping their expression. In this study, we exposed male zebra finches (Taeniopygia guttata) to environmental stress by exposing them to two temperature regimes (6 and 26°C) over a 4 week period.…

Personnalité, stratégies d'approvisionnement et d'appariement chez les Diamants Mandarins (taeniopygia guttata)

2011

In evolutionary biology, phenotypic variation has for a long time been considered as the raw material on which natural selection acts. However, research on the consistency of behaviour led to the development of the animal personality concept during the 1990s. This concept was based on the characterization of traits such as neophobia, aggressiveness, exploratory tendencies and risk-taking behaviour. Since then, several studies have shown that personality can evolve through natural selection and is related to many life-history traits, such as dispersal or anti-predator behaviour.Pairing strategies and foraging strategies are two fundamental components of an organism’s life, but their relation…

Plant-ant interaction in xerophilous ephemeral vegetation of S.E. Sardinia.

2003

Frequency and abundance of annual plants have been measured in 40 square plots, 0.36 m2 each, settled in an area of approximately 5 ha at the foothill of the Sarrabus massif, in S.E. Sardinia. 20 plots were randomly distributed at less than 5 m from the ant nests, further 20 at more than 30 m from the ants nests. The results showed a significantly lower plant density next to the ant nests, together with an higher species richness. Far from the nests, plots resulted dominated by relatively few species with a patchy distribution, while next to the nests the distribution of frequencies resulted more homogeneous. It is suggested that harvesting ants may contribute to the small-scale regulation …

Òliba, Lechuza común (VER0000120)

Altres noms vulgars: Barn owl guttata (Anglès), Effraie des clochers guttata (Francès), Schleiereule-guttata (Alemany) Gabinet de Vertebrats (Departament de Zoologia), Facultat de Ciències Biològiques (Campus de Burjassot), C/ Doctor Moliner, s/n, Bloque B. 5é plant, Burjassot (Valencia). Armari: 2-2 Valencia

Sex-specific transgenerational effects of early developmental conditions in a passerine.

2007

Most studies dealing with the trade-off between offspring number and quality have overlooked the long-term consequences for the progeny. High investment in offspring number usually results in an increased competition among nest mates. The deterioration of the early developmental conditions, due to this increased competition, can impair individual quality over the long term, and subsequently affect survival and lifetime fecundity. Moreover, the consequences of the allocation rule to offspring number vs. quality can extend across generations and give raise to grandparental effects. These transgenerational trade-offs have been explored rarely. In the present study, we manipulated the breeding …

Individual differences in behavioral consistency are related to sequential access to resources and body condition in a producer-scrounger game

2014

Investigating the evolution of consistent between-individual behavioral differences necessitates to explain the emergence of within-individual consistency. Relying on a recent mathematical model, we here test the prediction that the emergence of differences in within-individual consistency is related to the sequential access to resources in a frequency-dependent foraging game. To this end we used flocks of zebra finches (Taeniopygia guttata) engaged in a producer-scrounger foraging game. Tactic investment (i.e., the proportion of hops with the head down) significantly predicted successful tactic use (i.e., the proportion of seeds produced). In support of predictions, we found that individua…

Data from: Pairing context determines condition-dependence of song rate in a monogamous passerine bird

2013

Condition-dependence of male ornaments is thought to provide honest signals on which females can base their sexual choice for genetic quality. Recent studies show that condition-dependence patterns can vary within populations. Although long-term association is thought to promote honest signalling, no study has explored the influence of pairing context on the condition-dependence of male ornaments. In this study, we assessed the influence of natural variation in body condition on song rate in zebra finches (Taeniopygia guttata) in three different situations: during short and long encounters with an unfamiliar female, and within heterosexual mated pairs. We found consistent individual differe…