Replacement of traditional management by intensive agriculture may negatively affect birds.
Some very recent work indicates that sub-lethal doses of these herbicides may affect reproduction in birds.
Both local rainfall and NAO have been related by multivariate analyses to breeding population size in Doñana: the former is a better estimator of habitat availability for birds migrating into Doñana, while the latter may affect the probability that birds wintering in Africa will breed closer to their wintering grounds.
Réunion is an overseas department of France, but the Birds Directive does not apply outside Europe, so there is no European-level bird protection legislation effective on the island, despite the possibility that European Union agricultural and other funding may be adversely affecting birds and vulnerable habitats.
Réunion is an overseas department of France, but the Birds Directive does not apply outside Europe, so there is no bird protection legislation effective on the island, despite the possibility that EU agricultural and other funding may be adversely affecting birds and vulnerable habitats.
During the second site visit we characterized vegetation structure of crops within each 100 m-long transect to determine how microhabitat gradients may affect spatial distributions of birds.
While differences in climate are perhaps the most commonly invoked factors to explain differences in nest morphology, many other factors such as predation, brood parasitism, nest ectoparasitism, and variation in life history strategies (e.g., variation in reproductive effort) may affect nest morphology in birds.
As pointed out by an anonymous reviewer, variations in climate may, for example, directly and simultaneously affect bird communities and WNV transmission intensity.
An oil spill occurring in winter, when the puffins are far out at sea, may affect them less than inshore birds as the crude oil slicks soon get broken up and dispersed by the churning of the waves.
Factors such as the size of the human population also may affect the number of dead birds sighted and the number of persons exposed to WNV-infected mosquitoes.
