Search results for "Finch"
showing 10 items of 37 documents
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…
A molecular phylogeny of bullfinches Pyrrhula Brisson, 1760 (Aves: Fringillidae)
2011
Abstract We present a molecular phylogeny of bullfinches (Pyrrhula Brisson, 1760) based on 2357 bp DNA sequence information of mitochondrial genes (cyt-b, 16S rRNA) and nuclear introns (fib-7, GAPDH-11). The genus is clearly a monophyletic group. Within the limits of Pyrrhula, molecular methods support the subdivision of three main groups: (1) “Southeast-Asian bullfinches” (P. nipalensis and P. leucogenis), (2) “Himalayan bullfinches” (P. aurantiaca, P. erythaca, P. erythrocephala), and (3) “Eurasian bullfinches” (P. pyrrhula s.l.). Within the last group there are four different subgroups: (3a) P. (p.) murina, (3b) P. (p.) cineracea, (3c) P. (p.) griseiventris, and (3d) P. pyrrhula s.str. T…
The effect of social information from live demonstrators compared to video playback on blue tit foraging decisions.
2019
Video playback provides a promising method to study social interactions, and the number of video playback experiments has been growing in recent years. Using videos has advantages over live individuals as it increases the repeatability of demonstrations, and enables researchers to manipulate the features of the presented stimulus. How observers respond to video playback might, however, differ among species, and the efficacy of video playback should be validated by investigating if individuals’ responses to videos are comparable to their responses to live demonstrators. Here, we use a novel foraging task to compare blue tits’ (Cyanistes caeruleus) responses to social information from a live …
Increased susceptibility to oxidative stress as a proximate cost of reproduction
2004
Oxygen Supply from the Bird's Eye Perspective
2011
The visual process in the vertebrate eye requires high amounts of metabolic energy and thus oxygen. Oxygen supply of the avian retina is a challenging task because birds have large eyes, thick retinae, and high metabolic rates but neither deep retinal nor superficial capillaries. Respiratory proteins such as myoglobin may enhance oxygen supply to certain tissues, and thus the mammalian retina harbors high amounts of neuroglobin. Globin E (GbE) was recently identified as an eye-specific globin of chicken (Gallus gallus). Orthologous GbE genes were found in zebra finch and turkey genomes but appear to be absent in non-avian vertebrate classes. Analyses of globin phylogeny and gene synteny sho…
Inflammation and Life-Span
2005
In their Review “Inflammatory exposure and historical changes in human life-spans” (17 Sept., p. [1736][1]), C. E. Finch and E. M. Crimmins reinforce earlier suggestions that many diseases and disabilities of older age have their roots in previous exposures to infectious agents and other sources
Educare il bambino alla vita interiore. La lezione di Maria Montessori nel tempo della post-democrazia
2014
Maria Montessori’s pedagogy of interiority carried out in the “Houses of Children” is relevant to the postmodern age. By focusing on the care of the child’s inner life, Montessori’s lesson offers the new generations authentic religious practices, thus responding to the new, increasingly widespread, need for sacred. On this wake, contemporary pedagogy is re-launching childhood as a new resource for the adult, endeavouring to transform the environments where education takes place into laboratories of peace and democracy.
An experimental test of the dose-dependent effect of carotenoids and immune activation on sexual signals and antioxidant activity.
2004
Carotenoid‐based sexual traits are thought to be reliable indicators of male quality because they might be scarce and therefore might indicate the ability of males to gather high‐quality food and because they are involved in important physiological functions (as immune enhancers and antioxidants). We performed an experiment where male and female zebra finches (Taeniopygia guttata) were provided with increasing carotenoid doses in the drinking water during 4 weeks (bill color of this species is a carotenoid‐based sexual signal). Simultaneously, birds were split into two groups: one receiving weekly injections of Escherichia coli lipopolysaccharide in order to activate the immune system, the …
Age-dependent allocation of carotenoids to coloration versus antioxidant defences.
2009
SUMMARYAging is commonly attributed to age-related changes in oxidative damage due to an increased production of reactive oxygen species (ROS) and a weakened efficacy of enzymatic antioxidants. These age-related changes might therefore modify the use of dietary antioxidants, including carotenoids. As carotenoids are closely associated with the expression of secondary sexual signals, the allocation of carotenoids to sexual signal versus antioxidant defences may vary with age. In this study, we explored how carotenoid-based ornament and antioxidant activity varied with age and how an inflammatory-induced oxidative burst affected ornament and antioxidant activity across a range of ages. Using …
Testosterone and oxidative stress: the oxidation handicap hypothesis
2007
Secondary sexual traits (SST) are usually thought to have evolved as honest signals of individual quality during mate choice. Honesty of SST is guaranteed by the cost of producing/maintaining them. In males, the expression of many SST is testosterone-dependent. The immunocompetence handicap hypothesis has been proposed as a possible mechanism ensuring honesty of SST on the basis that testosterone, in addition to its effect on sexual signals, also has an immunosuppressive effect. The immunocompetence handicap hypothesis has received mixed support. However, the cost of testosterone-based signalling is not limited to immunosuppression and might involve other physiological functions such as the…