Zugunruhe

In ethology, zugunruhe is anxious behavior in migratory animals, especially in birds. 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. [cite journal|title=Migratory Sleeplessness in the White-Crowned Sparrow ("Zonotrichia leucophrys gambelii")|author= Rattenborg NC, Mandt BH, Obermeyer WH, Winsauer PJ, Huber R, et al.|journal=PLoS Biology|volume=2|issue=7|doi=10.1371/journal.pbio.0020212] Behaviourists have been able to study the endocrine controls and navigational mechanisms associated with migration by studying zugunruhe.cite journal|last=Helm|first=B.|coauthors=Gwinner, E.|year=2006|title=Migratory Restlessness in an Equatorial Nonmigratory Bird.|journal=PLoS Biol.|volume=4|issue=4|pages=e110|doi=10.1371/journal.pbio.0040110] [cite journal|last=Pott|first=Jaime |year=1998|title=Arrival Time from Spring Migration in Male Pied Flycatchers: Individual Consistency and Familial Resemblance.|journal=The Condor|volume=100|issue=4|pages=702–708|doi=10.2307/1369752|url=http://elibrary.unm.edu/sora/Condor/files/issues/v100n04/p0702-p0708.pdf]

This term is German in origin and is a compound of "Zug" (move, migration) and "Unruhe" (anxiety, restlessness).

Zugunruhe has been artificially induced in experiments by simulating long days. [cite journal|title=Induction of Zugunruhe by photostimulation of encephalic receptors in white-crowned sparrows|author=Yokoyama K & DS Farner|year=1978|journal= Science|volume=201|issue=4350|pages=76|doi=10.1126/science.566467] Some studies on White-crowned Sparrows have suggested that prolactin is involved in the pre-migratory hyperphagia (feeding), fattening and zugunruhe however others have found that prolactin may merely be associated with lipogenic (fat accumulation). [cite book|title=Control of bird migration|author=Peter Berthold|publisher=Springer|year=1996|isbn=0412363801|pages=96]

The phenomenon of Zugunruhe was generally believed to be found only in migratory species, however study of resident species shows low-level Zugunruhe, including the oriented activity, suggesting that the endogenous mechanisms for migratory behaviour may be present even in resident species. 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. [cite journal|last=Gwinner|first=Eberhard|year=1977|journal=Ann. Rev. Ecol. Syst.|title=Circannual rhythms in bird migration.|volume=8|pages=381–405|doi=10.1146/annurev.es.08.110177.002121]

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