''Zugunruhe'' ( /ˈ tsuːk:ʊnʁuːə/; German: suːk:ʊnʁuːə; lit. 'migration-anxiety') is the experience of migratory restlessness.

Ethology

ethology Ethology is the scientific study of animal behaviour, usually with a focus on behaviour under natural conditions, and viewing behaviour as an evolutionarily adaptive trait. Behaviourism as a term also describes the scientific and objecti ...

, ''Zugunruhe'' describes

anxious Anxiety is an emotion which is characterized by an unpleasant state of inner turmoil and includes feelings of dread over anticipated events. Anxiety is different than fear in that the former is defined as the anticipation of a future threat wh ...

behavior Behavior (American English) or behaviour (British English) is the range of actions and mannerisms made by individuals, organisms, systems or artificial entities in some environment. These systems can include other systems or organisms as we ...

in migratory

animal Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and go through an ontogenetic stage ...

s, especially in

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...

s during the normal migration period. When these animals are enclosed, such as in an

Emlen funnel An Emlen funnel is a bird cage shaped like an inverted cone, used to study bird behaviour, in particular birds' migratory instincts. It is named after S T and J T Emlen who introduced the technique in 1966. An ink pad is placed on the bottom, so w ...

, ''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.

"In accordance with their inherited calendars, birds get an urge to move. When migratory birds are held in captivity, they hop about, flutter their wings and flit from perch to perch just as birds of the same species are migrating in the wild. The caged birds ‘know’ they should be travelling too. This migratory restlessness, or Zugunruhe, was first described by Johann Andreas Naumann… hointerpreted Zugunruhe to be an expression of the migratory instinct in birds." --William Fiennes, ‘The Snow Geese’

Etymology

''Zugunruhe'' is borrowed from

German German(s) may refer to: * Germany (of or related to) **Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ge ...

; it is a

compound word In linguistics, a compound is a lexeme (less precisely, a word or sign) that consists of more than one stem. Compounding, composition or nominal composition is the process of word formation that creates compound lexemes. Compounding occurs when ...

consisting of ''Zug,'' "move, migration," and ''unruhe'' (anxiety, restlessness). The word was first published in 1707, when it was used to describe the "inborn migratory urge" in captive migrants. Though common nouns are normally not capitalised in English, ''Zugunruhe'' is sometimes capitalised following the German convention.

Effect

''Zugunruhe'' has been artificially induced in experiments by simulating long days. Some studies on

White-crowned Sparrow The white-crowned sparrow (''Zonotrichia leucophrys'') is a species of passerine bird native to North America. A medium-sized member of the New World sparrow family, this species is marked by a grey face and black and white streaking on the uppe ...

s 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). Researchers have been able to study the

endocrine The endocrine system is a messenger system comprising feedback loops of the hormones released by internal glands of an organism directly into the circulatory system, regulating distant target organs. In vertebrates, the hypothalamus is the neur ...

controls and

navigation Navigation is a field of study that focuses on the process of monitoring and controlling the movement of a craft or vehicle from one place to another.Bowditch, 2003:799. The field of navigation includes four general categories: land navigation ...

al mechanisms associated with migration by studying ''Zugunruhe''. 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. 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.

Ethology

Etymology

Effect

References

Further reading