Density-dependent winter survival of immatures in an irruptive raptor with pulsed breeding.

Highly mobile predators can show strong numerical responses to pulsed resources, sometimes resulting in irruptions where large numbers of young invade landscapes at a continental scale. High production of young in irruption years may have a strong influence on the population dynamics unless immature survival is reduced compared to non-irruption years. This could occur if subordinate individuals (mainly immatures) are forced into suboptimal habitats due to density-dependent effects in irruption years.

Author Correction: Arctic avian predators synchronise their spring migration with the northern progression of snowmelt.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Arctic avian predators synchronise their spring migration with the northern progression of snowmelt.

Migratory species display a range of migration patterns between irruptive (facultative) to regular (obligate), as a response to different predictability of resources. In the Arctic, snow directly influences resource availability. The causes and consequences of different migration patterns of migratory species as a response to the snow conditions remains however unexplored.

Norwegian house mice (Mus musculus musculus/domesticus): distributions, routes of colonization and patterns of hybridization.

We investigated the distributions and routes of colonization of two commensal subspecies of house mouse in Norway: Mus musculus domesticus and M. m. musculus.