In ethology, Zugunruhe describes anxious behavior in migratory animals, especially in birds during the normal migration period.
When these animals are enclosed, such as in an Emlen funnel, Zugunruhe serves to study the seasonal cycles of the migratory syndrome.
Zugunruhe involves increased activity towards and after dusk with changes in the normal sleep pattern.
[5] Some studies on White-crowned Sparrows have suggested that prolactin is involved in the pre-migratory hyperphagia (feeding), fattening and Zugunruhe.
[7] Further suggestions for endogenous programs are provided by observations that the number of nights on which Zugunruhe is exhibited by caged migrants appears related to the distance of migration involved.