Strong contribution of immigration to local population regulation: evidence from a migratory passerine

A mechanistic understanding of the dynamics of populations requires knowledge about the variation of the underlying demographic rates and about the reasons for their variability. In geographically open populations, immigration is often necessary to prevent declines, but little is known about whether immigration can contribute to its regulation. We studied the dynamics of a Red‐backed Shrike population ( Lanius collurio ) over 36 years in Germany...