Cultural Transmission of Feeding Behavior in the Black Rat (Rattus rattus)

Toward the end of the 19th century and beginning of the 20th century, most of the natural oak and pine forests in Israel were cut down. Upon inspecting these pine cone shafts more closely, it became clear that the cones had been detached from the branches of the trees on which they grew by gnawing, and the animal that had done so had systematically stripped them of all their scales and removed the seeds that lay concealed beneath. The black rat is an opportunistic feeder. Its flexible feeding behavior along with its highly adaptable behavioral mechanisms have led to the rats' worldwide distribution and successful invasion of new habitats. In Israel, rats are the sole exploiters of this arboreal habitat and have no competitors for the pine seeds that provide their main source of nourishment. In a pilot study, it was found that when naive adult rats are provided with cones from which the first four rows of scales had been removed, most of the rats are able to continue to open the rest of the cone and feed on the seeds. The reciprocal fostering experiment conducted in the chapter clearly indicates that the ability to strip pine cones is acquired through the social proximity of the pups to a dam experienced in stripping. The general picture that has emerged of cultural transmission in the case of cone opening is similar to other instances of transmission of feeding behavior from one generation to the next in other mammals.