Corruption

Irruption can occur for various, often interacting reasons. The waxwing ( Bombycilla garrulus ) migrates in large numbers into Western and Central Europe in some years when the populations in northern Eurasia multiply through successful breeding and the berries are scarce.

In ecology, irruption ( Latin for "attack, break-in" ) is a sudden immigration of non-resident animal species , mostly insects and birds , into an area. In its area of ​​origin, however, this migration is known as an eruption ( Latin for "eruption" ). The corresponding species are referred to as irruption or eruption birds in ornithology . The cause is usually a gradation in the area of ​​origin, i.e. a sudden increase in population . Such a fluctuation in the population dynamics is caused by many successful breeding in spring or by increased migration from the winter quarters of migratory birds . If there is a simultaneous shortage of food or breeding grounds, a population pressure arises, which causes many individuals to evasive into otherwise avoided regions. Often these birds do not return to their areas of origin and do not become native to the regions to which they migrate. Instead, there is a dead wandering , that is, the animals perish without returning.

swell

literature

• Rald Wassmann: Ornithological Pocket Lexicon . Explanation of technical terms. Aula-Verlag, Wiesbaden 1999, ISBN 3-89104-627-8 .

Individual evidence

1. ↑ Wassmann 1999, p. 97.
2. ↑ Wassmann 1999, p. 68.