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On the ontogeny of seed harvesting techniques in free ranging ground squirrels
Author: Heschl, Adolf
Journal: Behaviour
Volume: 125
Year: 1993
Pages: 39—50

Occasionally, adult European ground squirrels can be observed to practise a quite complex behavioural technique to obtain seed grains from the top of tall grass plants (e.g. Festuca ovina: 10-70 cm, Poaceae). They bite through the stem of a plant at the basis and, subsequently, know how to handle the fallen stem so as to successfully reach the food. The present field study aimed to analyse the detailed ontogeny which, in growing ground squirrels, leads to this behaviour. Data for 5 juveniles belonging to one litter were collected during an observation period of 38 successive days after the animals' first appearance above ground (video recordings). They show that this behaviour emerges as the final result of a whole series of successive developmental steps involving increasingly more efficient techniques in which simple techniques are gradually elaborated to more sophisticated ones. The underling causal mechanism is supposed to be operant conditioning based on increasingly more complex motor activities involving the animal's paws. Despite frequent social contacts, learning through imitation or even through instruction by the mother turned out to be not an important factor. With regard to cognitive abilities, the observations suggest experiments to verify the hypothesis of a beginning object permanence in ground squirrels.