The use of the nest for parental roosting and thermal consequences of the nest for nestlings and parents.

摘要: At temperate latitudes, altricial birds and their nestlings need to handle night temperatures well below thermoneutrality during the breeding season. Thus, energy costs of thermoregulation might constrain nestling growth, low nocturnal require resources that parents could otherwise have invested into day. To manipulate parental work rate, we performed brood size manipulations in marsh tits (Poecile palustris). Nest box were always above ambient temperature increased with increasing size. In line predictions, a large majority females (but no males) made use this benign environment for roosting. Furthermore, tending enlarged broods, thereby having harder day, reduced body at night. This expenditure. Our finding higher proportion enlarged, as compared control, continued nest roosting sites even after simulated predation event despite vulnerability predation, further highlighting conservation group. High attendance brood-reduced may indicate these prioritised self-maintenance by initiating other costly physiological adjustments, e.g. moult, when relieved from work. We suggest demand defending homeothermy is an element general trade-off between current future reproduction, i.e. daytime investment food provisioning potential short- long-term reduction risk. Even summer maintain stable temperature. Parents, thus, enter sufficient reserves cover requirements thermoregulation. As be used feeding adaptations reduce cost would selected for. manipulations, (Parus found typically spent thermally together brood. Females working hard day roost increase perceived risk predation. night, reducing gradient temperature,