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The present study investigated the relationship between reproductive success and stress‐coping styles in gilthead seabream Sparus aurata in captivity. To characterise stress‐coping styles, a total of 22 breeders were submitted to three different individual‐based tests, one group‐based test and post‐handling glucocorticoid quantification. To assess spawning participation, a microsatellite analysis was performed on a total of 2698 larvae, which allowed each offspring to be assigned unambiguously to a single parental couple. Overall, S. aurata showed defined proactive and reactive behavioural traits. Proactive breeders exhibited higher levels of activity and risk taking and lower glucocorticoid blood levels than reactive breeders. The stress‐coping style traits were consistent over time and context (different tests). Breeders that contributed to a higher number of progeny exhibited proactive behaviours, while those showing low progeny contribution exhibited reactive behaviour. Therefore, breeders with a high proportion of progeny (> 20%) had significantly higher activity and risk taking and lower cortisol than breeders with low progeny contribution (< 20%). In addition, males were more proactive than females and males exhibited significantly higher activity, risk taking and lower cortisol than females. This study is the first to establish in S. aurata breeders: (a) a relationship between stress‐coping styles and spawning success; (b) a relationship between stress‐coping styles and gender; and (c) the existence of proactive and reactive traits at the adult stage. [ABSTRACT FROM AUTHOR]

House mice (Mus musculus) produce a variable number of major urinary proteins (MUPs), and studies suggest that each individual produces a unique MUP profile that provides a distinctive odor signature controlling individual and kin recognition. This ‘barcode hypothesis’ requires that MUP urinary profiles show high individual variability within populations and also high individual consistency over time, but tests of these assumptions are lacking. We analyzed urinary MUP profiles of 66 wild-caught house mice from eight populations using isoelectric focusing. We found that MUP profiles of wild male house mice are not individually unique, and though they were highly variable, closer inspection revealed that the variation strongly depended on MUP band type. The prominent (‘major) bands were surprisingly homogenous (and hence most MUPs are not polymorphic), but we also found inconspicuous (‘minor’) bands that were highly variable and therefore potential candidates for individual fingerprints. We also examined changes in urinary MUP profiles of 58 males over time (from 6 to 24 weeks of age), and found that individual MUP profiles and MUP concentration were surprisingly dynamic, and showed significant changes after puberty and during adulthood. Contrary to what we expected, however, the minor bands were the most variable over time, thus no good candidates for individual fingerprints. Although MUP profiles do not provide individual fingerprints, we found that MUP profiles were more similar among siblings than non-kin despite considerable fluctuation. Our findings show that MUP profiles are not highly stable over time, they do not show strong individual clustering, and thus challenge the barcode hypothesis. Within-individual dynamics of MUP profiles indicate a different function of MUPs in individual recognition than previously assumed and advocate an alternative hypothesis (‘dynamic changes’ hypothesis).

Abstract: The conflict between sociability and foraging motivation in animals is considered to be of potential value for use in the management of grassland systems to improve grazing pattern of livestock over grasslands. However, individual differences in behaviors relating to this conflict have not been fully explored. Three experiments with two test repeats 1–3 days apart were conducted using 8–16 Japanese Black cows at intervals of approximately 3 weeks between Experiments 1 and 2 and 1 year between Experiments 2 and 3. Individual cows were tested in a grassed arena (85m×30m in Experiments 1 and 2, 130m×18m in Experiment 3) with an adjoining group pen holding the peers. Plastic washtubs (16 in Experiments 1 and 2, 25 in Experiment 3) containing 150g grain-based concentrate were placed at 5m increments on the centerline of the arena to entice test cows away from the group. Behavior of test cows were recorded for 30min as: maximum (D max) and mean (D mean) distance from the group, number of total (N total) and different (N diff) tub visits, and proportion of time eating concentrate (P eatconc) and grazing sward (P graze). Cows showed consistency in D max, D mean, N total and N diff over the short periods of 1–3 days (repeatability within experiments=0.41–0.80) and approximately 3 weeks (Pearson r between Experiments 1 and 2=0.81–0.91, P <0.05). Cows were further consistent in D max, N total and N diff over the extended period of 1 year (Pearson r between Experiments 2 and 3 and between Experiments 1 and 3=0.68–0.93, P <0.05). By contrast, P eatconc and P graze showed poorer consistency within cows, giving low repeatability estimates (0.29–0.34) in Experiment 2 and low Pearson r between Experiments 2 and 3 (0.30–0.31, P >0.05). It was concluded that D max, N total and N diff provide a reliable measure of the propensity for individual cows to trade sociability for feeding when the test is repeated over both short and extended periods. A test arena longer than 130m would be necessary for fully discriminating individual behavioral traits of cattle. [Copyright &y& Elsevier]

House mice ( Mus musculus) produce a variable number of major urinary proteins (MUPs), and studies suggest that each individual produces a unique MUP profile that provides a distinctive odor signature controlling individual and kin recognition. This 'barcode hypothesis' requires that MUP urinary profiles show high individual variability within populations and also high individual consistency over time, but tests of these assumptions are lacking. We analyzed urinary MUP profiles of 66 wild-caught house mice from eight populations using isoelectric focusing. We found that MUP profiles of wild male house mice are not individually unique, and though they were highly variable, closer inspection revealed that the variation strongly depended on MUP band type. The prominent ('major) bands were surprisingly homogenous (and hence most MUPs are not polymorphic), but we also found inconspicuous ('minor') bands that were highly variable and therefore potential candidates for individual fingerprints. We also examined changes in urinary MUP profiles of 58 males over time (from 6 to 24 weeks of age), and found that individual MUP profiles and MUP concentration were surprisingly dynamic, and showed significant changes after puberty and during adulthood. Contrary to what we expected, however, the minor bands were the most variable over time, thus no good candidates for individual fingerprints. Although MUP profiles do not provide individual fingerprints, we found that MUP profiles were more similar among siblings than non-kin despite considerable fluctuation. Our findings show that MUP profiles are not highly stable over time, they do not show strong individual clustering, and thus challenge the barcode hypothesis. Within-individual dynamics of MUP profiles indicate a different function of MUPs in individual recognition than previously assumed and advocate an alternative hypothesis ('dynamic changes' hypothesis).