Development of body temperature regulation in ostrich chicks

Abstract

1. Information in the literature indicates that young ostrich chicks, despite being precocial, are poor thermoregulators and may take between 8 and 12 weeks to develop efficient homeothermy. 2. We measured the body temperatures (T b ) of young ostrich chicks (1 to 10 d) at ambient temperatures between 13 and 28 C under controlled conditions in the laboratory and under typical farm-rearing conditions to assess their ability to thermoregulate. 3. Even 1-d-old ostriches could maintain a T b above 36 C at temperatures of 20 C and older chicks maintained typical adult T b at ambient temperatures of 13 C in a constant temperature room. 4. Chicks from 2-d-old could maintain adult T b s outdoors under a wide range of ambient temperatures and weather conditions. 5. We conclude that ostrich chicks have well developed homeothermy soon after hatching and that some of the higher rearing temperatures recommended in the literature are unnecessary . In appropriate climates, chicks can be allowed outdoors soon after hatching provided they are not exposed to unfavourable weather conditions. 6. Thermoregulation is, however, energetically expensive and thermoregulatory behaviour such as huddling may compete with other important activities like feeding.