Choosing an appropriate diet raises special problems for generalist herbivores, especially in areas where most of the plant species are poisonous. This was the case in our study site, the Bugac Juniper Forest (Kiskunsag National Park, Hungary). The main herbivore of this forest, the wild rabbit (Oryctolagus cuniculus), can choose from about 70 plant species, but several of these are toxic or only of medicinal value. Moreover, even the nutritious species of the sparse vegetation are available only for short periods. The annual mortality rate is extremely high for the young, only those individuals survive that can find suitable places to hide and the least poisonous plants to eat. This selection pressure might force the pups to get information about the edible food types as early as possible, i.e. in the nest from their mother.
This hypothesis was experimentally tested using domestic, chinchilla-breed rabbits. Three groups of females were kept on three different diets during the gestation and lactation periods. Just after weaning, food choices of differently treated mothers' pups were tested in a three-way food-choice test lasting 1 wk. The first choices were registered and the amount of food eaten from the different food items was measured during each test session. Analysis of the results of the first choices revealed that the animals started to eat the same food their mother had eaten during pregnancy and lactation. Analysis of the consumed amounts also supported this finding. Pups of treated mothers significantly preferred the aromatic plants their mother had eaten previously, even if it caused serious disadvantages to the young by reducing the number of offspring and increasing the mortality rate of the pups. The results of these experiments suggest that food preferences in wild rabbits can be transmitted from one generation to the other by social learning, although, to keep a balanced diet in an ever changing environment, individual experience and learning are indispensable.