ONTOGENIC CHANGES IN SLEEPING, DIVING AND FORAGING BEHAVIOR IN SHELDUCK (TADORNA-TADORNA) DUCKLINGS

Abstract

Shelduck ducklings show different types of diving behaviour: diving for food, flight-diving and dashing and diving in comfort situtations. These types differ by diving duration and the behaviour of the ducks. In diving for food diving duration and frequency decrease during the first 6 weeks. After this, no food diving was observed. Other feeding methods include sieving, upending, pecking on the surface of water, feeding on plants and foot-trampling. Except for feeding on plants, which was first observed in the 10th week, all feeding methods are present in one day old ducklings. The share of for-aging time is highest during the first 2 weeks of life- Afterwards it decreases (in females faster than in males) from about 50 to 20 %. During cold weather, it was still lower whereas resting and sleeping behaviour increased. After an increase during the first 10 weeks of life, the share of resting decreases to 25 - 40 % of observation time- Shelduck ducklings have 3 different sleeping postures: lying, standing on one leg, standing on two legs. During the first weeks of life ducklings only sleep standing on two legs or lying on the ground, the latter is being clearly preferred. Standing on one leg appeared in the 7th week. Its frequency increased and it became the most prominent resting pattern. Only during cold spells shelducks do return to sleep by lying on the ground. Under such conditions also sleeping in contact with one another reoccurs, which is typical for ducklings during their first weeks of life.