Zugunruhe

Zugunruhe (pronounced German pronunciation: [ˈtsuːkˌʔʊnʁuːə]) is a German compound word consisting of Zug (move, migration) and Unruhe (anxiety, restlessness).

In ethology it 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.[1] Researchers have been able to study the endocrine controls and navigational mechanisms associated with migration by studying Zugunruhe.[2][3]

Zugunruhe has been artificially induced in experiments by simulating long days.[4] 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 lipogenesis (fat accumulation).[5]

The phenomenon of Zugunruhe was generally believed to be found only in migratory species; however, a study of a resident species has shown low-level Zugunruhe, including oriented activity, suggesting that the endogenous mechanisms for migratory behaviour may be present even in a resident species.[2] 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.[6]

References

  1. ↑ Rattenborg NC, Mandt BH, Obermeyer WH, Winsauer PJ, Huber R, et al. (2004). "Migratory Sleeplessness in the White-Crowned Sparrow (Zonotrichia leucophrys gambelii)". PLoS Biology 2 (7): e212. doi:10.1371/journal.pbio.0020212. PMC 449897. PMID 15252455.
  2. 1 2 Helm, B.; Gwinner, E. (2006). "Migratory Restlessness in an Equatorial Nonmigratory Bird.". PLoS Biol. 4 (4): e110. doi:10.1371/journal.pbio.0040110. PMC 1420642. PMID 16555925.
  3. ↑ Pott, Jaime (1998). "Arrival Time from Spring Migration in Male Pied Flycatchers: Individual Consistency and Familial Resemblance." (PDF). The Condor (Cooper Ornithological Society) 100 (4): 702–708. doi:10.2307/1369752. JSTOR 1369752.
  4. ↑ Yokoyama K & DS Farner (1978). "Induction of Zugunruhe by photostimulation of encephalic receptors in white-crowned sparrows". Science 201 (4350): 76–9. doi:10.1126/science.566467. PMID 566467.
  5. ↑ Peter Berthold (1996). Control of bird migration. Springer. p. 96. ISBN 0-412-36380-1.
  6. ↑ Gwinner, Eberhard (1977). "Circannual rhythms in bird migration.". Ann. Rev. Ecol. Syst. 8 (1): 381–405. doi:10.1146/annurev.es.08.110177.002121.

Further reading

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