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The collapse of cycles in the dynamics of North American grouse populations

Författare:
Publiceringsår: 2004
Språk: Engelska
Sidor: 1135-1142
Publikation/Tidskrift/Serie: Ecology Letters
Volym: 7
Nummer: 12
Dokumenttyp: Artikel
Förlag: Blackwell Publishing

Sammanfattning

Cyclic dynamics of bird and mammal populations are commonly reported in northern latitudes throughout the world, and recent European observations on rodents and grouse suggest that cycle periods decline towards southern latitudes. To investigate latitudinal patterns of cyclic dynamics in North America, we assembled 27 long-term data sets collected between 1939 and 2001 for three grouse species. By fitting the data with autoregressive models to measure direct and delayed density dependence, we show that, in contrast to European studies, North American grouse exhibit period increases from north to south, with cycles collapsing via period lengthening. This occurs because delayed density dependence decreases in southern latitudes, whereas direct density dependence increases. These results show that cyclic dynamics can dissipate by period lengthening as well as the period shortening postulated for European grouse and rodents.

Disputation

Nyckelord

  • Biology and Life Sciences

Övriga

Published
Yes
  • ISSN: 1461-023X

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