| Popis: |
We provide evidence that nestbox-breeding tits roost in their boxes at night during the egg-laying period, but are able to do so while avoiding initiating incubation, despite choosing to settle into the nest-cup. Nest-cup temperatures of Great Tits Parus major, during the egg-laying period, were usually below the threshold for embryo development. This suggests an ability to control heat transfer to the eggs in spite of the close proximity of the female to her clutch. We suggest that an important benefit of roosting in the nest-cup during the egg-laying period is reduced thermoregulatory costs, which may be important in moderating the energetic costs of egg production. Another possible advantage is that developmental abnormalities associated with egg-chilling are avoided. |
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