Showing papers by "Sophie Lumineau published in 2019"

Postnatal care generates phenotypic behavioural correlations in the Japanese quail

Abstract: Behavioural phenotypes can be highly constrained by interdependent behavioural traits. Studies in different taxa showed that these behavioural phenotypic correlations are not universal within a species and can differ between populations exposed to different environmental pressures. Empirical studies are required to better understand the relative contributions of long-term adaptive processes and direct ontogenetic mechanisms in the development of these phenotypic behavioural correlations. In the present study, we investigated the role of postnatal nurturing care on the development of behavioural correlations in a precocial bird model, the Japanese quail (Coturnix coturnix japonica). We compared phenotypic correlations between two populations: 41 artificially reared birds (maternally deprived) and 36 birds fostered by unrelated females. Behavioural responses were measured at the age when birds naturally disperse, with three widely used behavioural tests to assess fearfulness and sociality: tonic immobility, open-field and emergence tests. Our results show that when quail chicks are reared by a foster mother, more phenotypic correlations appeared in the population including correlations within and across behavioural functions and between behavioural responses and chick mass. In contrast, chicks reared without a foster mother presented much fewer behavioural correlations and those were limited to functionally linked behaviours. Our results also highlight that the effect of mothering on phenotypic correlations is sex-specific, with a greater effect on males. We discuss the organisational role of parents on the development of behavioural correlations, the mechanisms likely to support this influence, as well as the reasons for sexual dimorphism. Mothers deeply influence the behavioural development of their offspring during the postnatal stage. Whether maternal presence and nurturing behaviour also affect correlations between behavioural responses of their offspring at a population level remains underexplored and unclear. In the current study, we used an adoption procedure to demonstrate the critical role of maternal postnatal care for the development of behavioural correlations in a precocial bird model widely used for the study of behavioural ontogeny: the Japanese quail. Our findings highlight that the presence of a maternally behaving female during early life promotes the development of correlations between behavioural responses both within and across behavioural functions in males but not in females.

Mother-chick interactions are affected by chicks' sex and brood composition in Japanese quail.

Abstract: Sex is a trait which leads mothers to invest asymmetrically in their young, especially in species with a strong dimorphism. Authors usually consider that members of the largest sex require the most investment by mothers. In other cases, mothers care preferentially for members of the sex that increase their fitness, e.g. males, in numerous species. In quail, a precocial bird, mother seems to take more care of their males which are more sensitive to their separation. This study investigates the influence of chicks' sex and brood's sexual composition on the maternal behavior of quail. We evaluated three batches of mothers, composed of (a) unisex broods of males (MM), (b) unisex broods of females (FF), and (c) mixed sex broods (Mx). We recorded mother-chick interactions during 11 days of mothering. We found that MM mothers spent more time warming their chicks and FF mothers were more active. Moreover, females rejected more aggressively and earlier their female chicks than their male chicks. Finally, Mx chicks, whatever their sex, interacted more with their mothers. Our results highlight a greater quantity and quality of maternal care towards male. Mothers invest more in male chicks. We discussed results in terms of each sex's needs.

High social motivation induces deficits in maternal behavior but not plasticity of the subventricular zone in Japanese quail ( Coturnix japonica )

Abstract: Maternal behaviour develops differently depending on the characteristics of an individual, such as age or emotional reactivity. Social motivation, defined as the propensity to establish social contact, has received little attention in relation to maternal behaviour in birds. In addition, the transition to motherhood is a time of plasticity in the brain of the new mother in mammals. However, it remains to be determined how maternal brain plasticity is affected in avian species. The present study investigated how a the social motivation of a mother alters maternal behaviour and brain plasticity of the Japanese quail (Coturnix japonica). Adult females from lines selected for high and low social motivation were exposed to chicks for 11 days. After maternal care testing, and at matched time points in controls, the brains of females were perfused for assessment of doublecortin-immunoreactive staining, a marker of neurogenesis, in the subventricular zone (SVZ), a neurogenic niche. The results obtained showed that high socially motivated female quail spent significantly less time performing maternal behaviour when exposed to chicks compared to low socially motivated females. Moreover, the warming of chicks by high socially motivated females involved less covering postures and mothers were more rejecting of chicks. Interestingly, the plasticity indicators in the SVZ did not differ between low and high socially motivated females and were not associated with differences in maternal caregiving when using doublecortin-immunoreactive staining. Thus, high social motivation in this avian species does not favour maternal behaviour and this level of motivation to the mother is not related to changes in neuroplasticity in the SVZ of the female quail.