Annual cycle of patterns of activity rhythms in beaver colonies (Castor canadensis)


Beavers studied under natural conditions near Québec City, Canada, displayed a yearly cycle of patterns of activity rhythms. In winter, the beaver colonies had a free-running circadian rhythm of period length 26.25 to 28.0 h, with or without relative coordination, depending on available light intensity, which in turn depends on ice and snow cover conditions; in summer, their activity rhythm followed a “normal” 24 h period. Transitions between these two patterns suggest that annual variations in the beaver's physiological state affect their reaction towards the presence or absence of a Zeitgeber.

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  1. Aleksiuk, M., Cowan, I. McT.: The winter metabolic depression in Arctic beavers (Castor canadensis Kuhl) with comparisons to California beavers. Canad. J. Zool.47, 965–979 (1969)

    Google Scholar 

  2. Andreasson, S.: Seasonal changes in diel activity ofCottus poeeilopus andC. gobio (Pisces) at the arctic circle. Oikos24, 16–23 (1973)

    Google Scholar 

  3. Aschoff, J.: Response curves in circadian periodicity. In: Circadian clocks, p. 95–111, Aschoff, J. (ed.). Amsterdam: North-Holland Publ. Co. 1965

    Google Scholar 

  4. Bovet, J., Oertli, E.: Free-running circadian activity rhythms in free-living beaver (Castor canadensis). J. comp. Physiol.92, 1–10 (1974)

    Google Scholar 

  5. Bünning, E.: The physiological clock, 2nd ed. Berlin-Heidelberg-New York: Springer 1967

    Google Scholar 

  6. Enright, J. T.: The search for rhythmicity in biological time-series. J. theor. Biol.8, 425–468 (1965a)

    Google Scholar 

  7. Enright, J. T.: Synchronization and ranges of entrainment. In: Circadian clocks, p. 112–124, Aschoff, J. (ed.). Amsterdam: North-Holland Publ. Co. (1965b)

    Google Scholar 

  8. Evernden, L. N., Fuller, W. A.: Light alteration caused by snow and its importance to subnivean rodents. Canad. J. Zool.50, 1023–1032 (1972)

    Google Scholar 

  9. Little, E. M., Allen, M. B., Wright, F. F.: Field measurement of light penetration through sea ice. Arctic25, 28–33 (1972)

    Google Scholar 

  10. Menaker, M.: The free-running period of the bat clock; seasonal variations at low body temperature. J. cell. comp. Physiol.57, 81–86 (1961)

    Google Scholar 

  11. Müller, K.: Die Tages- und Jahresperiodik der BuntflossenkoppeCottus poecilopus Heckel am Polarkreis. Oikos, Suppl.13, 108–121 (1970)

    Google Scholar 

  12. Novakowski, N. S.: The winter bioenergetics of a beaver population in northern latitudes. Canad. J. Zool.45, 1107–1118 (1967)

    Google Scholar 

  13. Pohl, H.: Die Aktivitätsperiodik von zwei tagaktiven Nagern,Funambulus palmatum undEutamias sibiricus, unter Dauerlichtbedingungen. J. comp. Physiol.78, 60–74 (1972)

    Google Scholar 

  14. Stephenson, A. B.: Temperatures within a beaver lodge in winter. J. Mammal.50, 134–136 (1969)

    Google Scholar 

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Submitted by the senior author to the Ecole des Gradués, Université Lavai, in partial fulfillment of the requirements for the degree of Master of Science.

This work was supported by the National Research Council of Canada (grant no. A 6639 to J.B.). The computer processing of the data was done by the Centre de Traitement de l'Information, Université Laval. We are grateful to Dr. G. Power for his critical review of the manuscript.

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Potvin, C.L., Bovet, J. Annual cycle of patterns of activity rhythms in beaver colonies (Castor canadensis). J. Comp. Physiol. 98, 243–256 (1975).

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  • Light Intensity
  • Natural Condition
  • Physiological State
  • Circadian Rhythm
  • Snow Cover