Effects of the social environment during adolescence on the development of social behaviour, hormones and morphology in male zebra finches (Taeniopygia guttata)

Abstract Background Individual differences in behaviour are widespread in the animal kingdom and often influenced by the size or composition of the social group during early development. In many vertebrates the effects of social interactions early in life on adult behaviour are mediated by changes in maturation and physiology. Specifically, increases in androgens and glucocorticoids in response to social stimulation seem to play a prominent role in shaping behaviour during development. In addition to the prenatal and early postnatal phase, adolescence has more recently been identified as an important period during which adult behaviour and physiology are shaped by the social environment, which so far has been studied mostly in mammals. We raised zebra finches ( Taeniopygia guttata ) under three environmental conditions differing in social complexity during adolescence\ua0-\ua0juvenile pairs, juvenile groups, and mixed-age groups - and studied males\u2019 behavioural, endocrine, and morphological maturation, and later their adult behaviour. Results As expected, group-housed males exhibited higher frequencies of social interactions. Group housing also enhanced song during adolescence, plumage development, and the frequency and intensity of adult courtship and aggression. Some traits, however, were affected more in juvenile groups and others in mixed-age groups. Furthermore, a testosterone peak during late adolescence was suppressed in groups with adults. In contrast, corticosterone concentrations did not differ between rearing environments. Unexpectedly, adult courtship in a test situation was lowest in pair-reared males and aggression depended upon the treatment of the opponent with highest rates shown by group-reared males towards pair-reared males. This contrasts with previous findings, possibly due to differences in photoperiod and the acoustic environment. Conclusion Our results support the idea that effects of the adolescent social environment on adult behaviour in vertebrates are mediated by changes in social interactions affecting behavioural and morphological maturation. We found no evidence that long-lasting differences in behaviour reflect testosterone or corticosterone levels during adolescence, although differences between juvenile and mixed-age groups suggest that testosterone and song behaviour during late adolescence may be associated

Oscillating magnetic field disrupts magnetic orientation in Zebra finches, Taeniopygia guttata

Background Zebra finches can be trained to use the geomagnetic field as a directional cue for short distance orientation. The physical mechanisms underlying the primary processes of magnetoreception are, however, largely unknown. Two hypotheses of how birds perceive magnetic information are mainly discussed, one dealing with modulation of radical pair processes in retinal structures, the other assuming that iron deposits in the upper beak of the birds are involved. Oscillating magnetic fields in the MHz range disturb radical pair mechanisms but do not affect magnetic particles. Thus, application of such oscillating fields in behavioral experiments can be used as a diagnostic tool to decide between the two alternatives. Methods In a setup that eliminates all directional cues except the geomagnetic field zebra finches were trained to search for food in the magnetic north/south axis. The birds were then tested for orientation performance in two magnetic conditions. In condition 1 the horizontal component of the geomagnetic field was shifted by 90 degrees using a helmholtz coil. In condition 2 a high frequently oscillating field (1.156 MHz) was applied in addition to the shifted field. Another group of birds was trained to solve the orientation task, but with visual landmarks as directional cue. The birds were then tested for their orientation performance in the same magnetic conditions as applied for the first experiment. Results The zebra finches could be trained successfully to orient in the geomagnetic field for food search in the north/south axis. They were also well oriented in test condition 1, with the magnetic field shifted horizontally by 90 degrees. In contrast, when the oscillating field was added the directional choices during food search were randomly distributed. Birds that were trained to visually guided orientation showed no difference of orientation performance in the two magnetic conditions

Quality differences assessment in canned sardine (Sardina pilchardus) by fluorescence detection

5 páginas, 4 figuras, 2 tablas.-- This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Agricultural and Food Chemistry, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/jf970056lChilled (0, 2, 6, 10, 13, and 15 days) and frozen (0, 0.5, 2, 4, 8, and 12 months) sardines were used to determine the influence of such storage times of fish over the quality of the final canned product. Traditional determinations of lipid quality (free fatty acids content, thiobarbituric acid index, and polyene index) were studied and compared with the formation of fluorescent compounds expressed as the ratio between fluorescence readings taken at two excitation/emission maxima (393/463 and 327/415 nm). No clear correlations were found between the common measurements of lipid deterioration and the time of storage prior to canning. Satisfactory correlations were found between the fluorescence ratio obtained from the filling medium of cans and the time of storage of the starting material (r = 0.90 and 0.91 in brine- and oil-canned samples, respectively). According to the present results, fluorescence detection of interaction compounds can provide a rapid and sensible method to assess quality differences in the final product as it relates to the quality of the raw material usedWe thank the Xunta de Galicia for financial support (Project XUGA 402 01B93).Peer reviewe

Spatial Orientation in Japanese Quails (Coturnix coturnix japonica)

Finding a given location can be based on a variety of strategies, for example on the estimation of spatial relations between landmarks, called spatial orientation. In galliform birds, spatial orientation has been demonstrated convincingly in very young domestic chicks. We wanted to know whether adult Japanese quails (Coturnix coturnix japonica) without food deprivation are also able to use spatial orientation. The quails had to learn the relation of a food location with four conspicuous landmarks which were placed in the corners of a square shaped arena. They were trained to find mealworms in three adjacent food cups in a circle of 20 such cups. The rewarded feeders were located during training between the same two landmarks each of which showed a distinct pattern. When the birds had learned the task, all landmarks were displaced clockwise by 90 degrees. When tested in the new situation, all birds redirected their choices with respect to the landmark shift. In subsequent tests, however, the previously correct position was also chosen. According to our results, quails are using conspicuous landmarks as a first choice for orientation. The orientation towards the previously rewarded location, however, indicates that the neuronal representation of space which is used by the birds also includes more fine grain, less conspicuous cues, which are probably also taken into account in uncertain situations. We also presume that the rare orientation towards never rewarded feeders may be due to a foraging strategy instead of being mistakes

Social background matters : the importance of adolescent peer experience for adult social behavior

Ruploh T. Social background matters : the importance of adolescent peer experience for adult social behavior. Bielefeld; 2014

Captive domesticated zebra finches (Taeniopygia guttata) have increased plasma corticosterone concentrations in the absence of bathing water

Krause ET, Ruploh T. Captive domesticated zebra finches (Taeniopygia guttata) have increased plasma corticosterone concentrations in the absence of bathing water. Applied Animal Behaviour Science. 2016;182:80-85.Keeping animals in captivity should always favour conditions that aim to improve their welfare withrespect to species-specific requirements. For laboratory animals, the majority of welfare issues havebeen explored in rodents thus far, whereas the effect of housing conditions on the well-being of avian labspecies has received relatively little attention. Here, we investigate the importance of access to a waterbath in captivity on the welfare of a drought-adapted passerine, the zebra finch (Taeniopygia guttata).Zebra finches can survive long periods of drought in the wild, which also includes a lack of surface waterfor bathing, but if water is available, they regularly take the opportunity to bathe in water. Water bathsrepresent an important comfort behaviour for zebra finches, especially because the birds do not take dustbaths. Here, we wanted to examine the role of water baths in relation to corticosterone concentrationsas an indicator of well-being in captive zebra finches. We sought to determine how important it is toprovide water baths to zebra finches in captivity. Therefore, we repeatedly quantified the basal plasmastress hormone levels, i.e., corticosterone (CORT), and the body weight of individuals over a three-monthperiod. During this time, control birds had permanent access to a water bath, while treatment birdsexperienced a 30-day period without the opportunity to bathe during the second month. We demonstratethat zebra finches lacking bathing opportunities show higher basal plasma CORT concentrations (GLM,p = 0.034) but do not differ in body weight in comparison to control birds (GLM, p = 0.31). Our resultsshow that even for birds that can tolerate long periods of drought in their natural habitat, access to awater bath is essential for their well-being and their welfare, and thus, water baths should be providedunder captive housing conditions. As chronically elevated stress hormone levels can have short-andlong-term detrimental effects, our findings have important implications for welfare considerations inthe management of one of the most used laboratory birds

Adolescent social environment shapes sexual and aggressive behaviour of adult male zebra Finches (Taeniopygia guttata).

Ruploh T, Bischof H-J, von Engelhardt N. Adolescent social environment shapes sexual and aggressive behaviour of adult male zebra Finches (Taeniopygia guttata). Bielefeld University; 2013

Effects of social conditions during adolescence on courtship and aggressive behavior are not abolished by adult social experience

Ruploh T, Bischof H-J, von Engelhardt N. Effects of social conditions during adolescence on courtship and aggressive behavior are not abolished by adult social experience. Bielefeld University; 2015

Experimental arena.

<p>In the arena (150×150×50 cm) 20 identical food cups were arranged in a circle and four distinct visual landmarks placed in the corners. The central, transparent starting cylinder could be retracted into the floor. Filled circles represent baited food cups. Quails were trained to find food between two specific landmarks (A). In the test, landmarks and positions of baited food cups were shifted 90° clockwise (B).</p