Body reserves and nutritional needs during laying preparation in barn owls
| Autor: | Joël M. Durant, C. Thouzeau, Sylvie Massemin, Yves Handrich |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Physiology
media_common.quotation_subject Oviposition Nocturnal Biochemistry Nesting Behavior Endocrinology Animal science Captive breeding Animals Ecology Evolution Behavior and Systematics media_common Ovum biology Ecology Bird of prey Tyto Water biology.organism_classification Lipid Metabolism Strigiformes Brood patch Body Composition Animal Science and Zoology Animal Nutritional Physiological Phenomena Female Reproduction Energy Metabolism Moulting Barn (unit) |
| Zdroj: | Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology. 170(3) |
| ISSN: | 0174-1578 |
| Popis: | To investigate the composition of the body reserves made during pre-laying by breeding European barn owls (Tyto alba), we have analysed the body composition of captive breeding and non-breeding females sacrificed during the laying period. The data obtained were compared to the daily requirement for egg formation obtained by an egg composition analysis and the timing of egg synthesis. This study demonstrates that body mass gain observed in breeding females (+ 38.3 g after eggs in formation and gonadal tractus were removed) was not the consequence of an accumulation of body fuels like lipids but of mainly water and lean material. The lipidic reserves were found to be less important in breeding than in non-breeding females and their localisation modified; lipids were absent from medullar bones in breeding females which liberated room for other storage. The subcutaneous tissue, which was homogeneous in non-breeding females, was located principally under the brood patch in breeding females. Nutrients and energy required during egg formation could be obtained without modification of daily food intake. These results show that a laying event can be initiated in 14 days and that the onset of reproduction is not triggered by body condition in barn owls. The water accumulation observed is suggested to be the mere consequence of an increase of protein metabolism (egg and moult). These results intimate that the body mass increase observed in diurnal and nocturnal raptors during laying preparation, interpreted as an energy safety strategy, ought to be reconsidered. |
| Databáze: | OpenAIRE |
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