Prenatal sensory experience affects hatching behavior in domestic chicks (Gallus gallus) and Japanese quail chicks (Coturnix coturnix japonica).

Species-typical developmental outcomes result from organismic and environmental constraints and experiences shared by members of a species. We examined the effects of enhanced prenatal sensory experience on hatching behaviors by exposing domestic chicks (n = 95) and Japanese quail (n = 125) to one of four prenatal conditions: enhanced visual stimulation, enhanced auditory stimulation, enhanced auditory and visual stimulation, or no enhanced sensory experience (control condition). In general, across species, control embryos had slower hatching behaviors than all other embryos. Embryos in the auditory condition had faster hatching behaviors than embryos in the visual and control conditions. Auditory-visual condition embryos showed similarities to embryos exposed to either auditory or visual stimulation. These results suggest that prenatal sensory experience can influence hatching behavior of precocial birds, with the type of stimulation being a critical variable. These results also provide further evidence that species-typical outcomes are the result of species-typical prenatal experiences.

Prenatal visual experience induces postnatal motor laterality in Japanese quail chicks (Coturnix coturnix japonica).

Species-typical prenatal visual stimulation in avian species is a necessary component in the development of population level lateralized behaviors. This relationship suggests that species-typical developmental outcomes result from organismic and environmental constraints and experiences shared by members of a species. We examined the effects of prenatal visual experience on the development of turning bias and footedness in Japanese quail chicks, a species which does not demonstrate a naturally occurring level of population laterality and only weak individual laterality. Chicks (n=167) were exposed to one of four prenatal conditions: both eye systems exposed to enhanced visual experience, right eye system exposed/left eye system occluded, left eye system exposed/right eye system occluded, or no enhanced visual experience. When subjects were exposed to prenatal visual stimulation, individual and population level laterality was induced. These results suggest that unilateral prenatal visual experience to the right eye or left eye system is sufficient to induce and influence the direction of individual and population laterality in a species that does not normal demonstrate such biases. The results also provide further evidence that prenatal sensory experiences can elicit the development of postnatal lateralization.

Asymmetrical hatching behaviors: the development of postnatal motor laterality in three precocial bird species.

The effects of asymmetrical hatching behaviors on the development of turning bias and footedness in domestic chicks, bobwhite quail, and Japanese quail chicks were examined. Control tests with incubator reared domestic chicks and bobwhite quail revealed significant individual and population left-side turning bias and right footedness. When late stage hatching behaviors were disrupted, population laterality was not evident and individual laterality was reduced. By contrast, Japanese quail chicks demonstrated no population turning bias or footedness and only weak individual biases. Disruption of hatch behaviors further decreased laterality. Examination of discarded eggshells showed significant differences in the degree of rotation made to cut out of the egg by Japanese quail versus domestic chicks and bobwhite quail. Taken together these findings suggest that the counterclockwise hatching behaviors that are characteristic of many precocial bird species serve to facilitate the development of motor laterality at both the individual and population level.