, Volume 103, Issue 2, pp 241–248 | Cite as

Effects of predator removal on vertebrate prey populations: birds of prey and small mammals

  • Kai Norrdahl
  • Erkki Korpimäki
Original Paper


We studied the effects of removal of breeding nomadic avian predators (the kestrel, Falco tinnunculus and Tengmalm's owl, Aegolius funereus) on small mammals (voles of the genera Microtus and Clethrionomys and the common shrew, Sorex araneus) during 1989–1992 in western Finland to find out if these predators have a regulating or limiting impact on their prey populations. We removed potential breeding sites of raptors from five manipulation areas (c. 3 km2 each), whereas control areas had nest-boxes in addition to natural cavities and stick-nests. Densities of small mammals were monitored by snap-trapping in April, June, and August, and densities of mammalian predators (the least weasel, Mustela nivalis nivalis, the stoat, M. erminea and the red fox, Vulpes vulpes) by snow tracking in early spring and late autumn. The yearly mean number of raptor breeding territories was 0.2–1.0 in reduction areas and 3.0–8.2 in control areas. Breeding raptors alone did not regulate prey populations in the long term, but probably caused short-term changes in the population dynamics of both the main prey, the sibling vole (Microtus rossiaemeridionalis) and an alternative prey (the common shrew). The densities of an alternative prey, the bank vole (Clethrionomys glareolus) decreased in raptor reduction areas, most likely due to increased least weasel predation pressure in the absence of breeding avian predators.

Key words

Avian predator Least weasel Population fluctuation Population regulation Vole 


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  1. Andersson M, Jonasson S (1986) Rodent cycles in relation to food resources on an alpine heath. Oikos 46:93–106Google Scholar
  2. Angerbjorn A (1989) Mountain hare populations on islands: effects of predation by red fox. Oecologia 81:335–340Google Scholar
  3. Crawley MJ (1992) Overview. In: Crawley MJ (ed) Natural enemies: The population biology of predators and diseases. Blackwell. Oxford, pp 476–489Google Scholar
  4. Desy EA, Batzli GO (1989) Effects of food availability and predation on prairie vole demography: a field experiment. Ecology 70:411–421Google Scholar
  5. Elton C (1942) Voles, mice and lemmings: problems in population dynamics. Oxford University Press, OxfordGoogle Scholar
  6. Erlinge S (1987) Predation and noncyclicity in a microtine population in southern Sweden. Oikos 50:347–352Google Scholar
  7. Erlinge S, Göransson G, Hansson L, Högstedt G, Liberg O, Nilsson IN, Nilsson T, Schantz T von, Sylven M (1983) Predation as a regulating factor in small rodent populations in southern Sweden. Oikos 40:36–52Google Scholar
  8. Hanski I (1987) Populations of small mammals cycle unless they don't Trends Ecol Evol 2:55–56Google Scholar
  9. Hanski I, Korpimäki E (1994) Microtine rodent dynamics in northern Europe: parametrized models for the predator-prey interaction. Ecology (in press)Google Scholar
  10. Hanski I, Turchin P, Korpimäki E, Henttonen H (1993) Population oscillations of boreal rodents: regulation by mustelid predators leads to chaos. Nature 364:232–235Google Scholar
  11. Hansson L (1979) Food as a limiting factor for small rodent numbers: tests of two hypotheses. Oecologia 37:297–314Google Scholar
  12. Hansson L (1987) An interpretation of rodent dynamics as due to trophic interactions. Oikos 50:308–318Google Scholar
  13. Heikkilä J, Kaarsalo K, Mustonen O, Pekkarinen P (1993) Influence of predation risk on early development and maturation in three species of Clethrionomys voles. Ann Zool Fenn 30:153–161Google Scholar
  14. Henttonen H, Oksanen T, Jortikka A, Haukisalmi V (1987) How much do weasels shape microtine cycles in the northern Fennoscandian taiga? Oikos 50:353–365Google Scholar
  15. Hurlbert SH (1984) Pseudoreplication and the design of ecological field experiments. Ecol Monogr 54:187–211Google Scholar
  16. Jedrzejewski W, Jedrzejewska B (1990) Effect of a predator's visit on the spatial distribution of bank voles: experiments with weasels. Can J Zool 68:660–666Google Scholar
  17. Korpimäki E (1981) On the ecology and biology of Tengmalm's owl (Aegolius funereus) in southern Ostrobothnia and Suomenselkä western Finland. Acta Univ Oul A Biol 13:1–84Google Scholar
  18. Korpimäki E (1984) Population dynamics of birds of prey in relation to fluctuations in small mammal populations in western Finland. Ann Zool Fenn 21:287–293Google Scholar
  19. Korpimäki E (1987) Dietary shifts, niche relationships and reproductive output of coexisting kestrels and long-eared owls. Oecologia 74:277–285Google Scholar
  20. Korpimäki E (1989) Breeding performance of Tengmalm's owl Aegolius funereus: effects of supplementary feeding in a peak vole year. Ibis 131:51–56Google Scholar
  21. Korpimäki E (1993) Regulation of multiannual vole cycles by density-dependent avian and mammalian predation? Oikos 66:359–363Google Scholar
  22. Korpimäki E, Norrdahl K (1989a) Avian predation on mustelids in Europe. 1. Occurrence and effects on body size variation and life traits. Oikos 55:205–215Google Scholar
  23. Korpimäki E, Norrdahl K (1989b) Avian predation on mustelids in Europe. 2. Impact on small mustelid and microtine dynamics —a hypothesis. Oikos 55:273–276Google Scholar
  24. Korpimäki E, Norrdahl K (1989c) Predation of Tengmalm's owls: numerical responses, functional responses and dampening impact on population fluctuations of voles. Oikos 54:154–164Google Scholar
  25. Korpimäki E, Norrdahl K (1991a) Do breeding nomadic avian predators dampen population fluctuations of small mammals? Oikos 62:195–208Google Scholar
  26. Korpimäki E, Norrdahl K (1991b) Numerical and functional responses of kestrels, short-eared owls, and long-eared owls to vole densities. Ecology 72:814–826Google Scholar
  27. Korpimäki E, Norrdahl K, Rinta-Jaskari T (1991) Responses of stoats and least weasels to fluctuating voles abundances: is the low phase of the vole cycle due to mustelid predation? Oecologia 88:552–561Google Scholar
  28. Korpimäki E, Norrdahl K, Valkama J (1994) Reproductive investment under fluctuating predation risk: microtine rodents and small mustelids. Evol Ecol 8:1–12Google Scholar
  29. Krebs CJ, Myers JH (1974) Population cycles in small mammals. Adv Ecol Res 8:267–399Google Scholar
  30. Krebs CJ, Gaines MS, Keller BL, Myers JH, Tamarin RH (1973) Population cycles in small rodents. Science 179:35–41Google Scholar
  31. Laine K, Henttonen H (1983) The role of plant production in microtine cycles in northern Fennoscandia. Oikos 40:407–418Google Scholar
  32. Laine K, Henttonen H (1987) Phenolics/nitrogen ratios in the blueberry Vaccinium myrtillus in relation to temperature and microtine density in Finnish Lapland. Oikos 50:389–395Google Scholar
  33. Lidicker WZ (1988) Solving the enigma of microtine “cycles”. J Mammal 69:225–235Google Scholar
  34. Marcström V, Kenward RE, Engren E (1988) The impact of predation on boreal tetraonids during vole cycles: an experimental study. J Anim Ecol 57:859–872Google Scholar
  35. Marcström V, Keith LB, Engren E, Gary JR (1989) Demographic responses of artic hares (Lepus timidus) to experimental reduction of red foxes (Vulpes vulpes) and martens (Martes martes). Can J Zool 67:658–668Google Scholar
  36. Myllymäki A, Paasikallio A, Pankakoski E, Kanervo V (1971) Removal experiments on small quadrats as a means of rapid assessment of the abundance of small mammals. Ann Zool Fenn 8:177–185Google Scholar
  37. Newsome AE, Parer I, Catling PC (1989) Prolonged prey suppression by carnivores — predator-removal experiments. Oecologia 78:458–467Google Scholar
  38. Norrdahl K, Korpimäki E (1993) Predation and interspecific competition in two Microtus voles. Oikos 66:149–158Google Scholar
  39. Norrdahl K, Korpimäki E (1995) Small carnivores and prey population dynamics in summer. Ann Zool Fenn (in press)Google Scholar
  40. Oksanen L, Ericson L (1987) Dynamics of tundra and taiga populations of herbaceous plants in relation to the Tihomirov-Fretwell and Kalela-Tast hypotheses. Oikos 50:381–388Google Scholar
  41. Oksanen L, Oksanen T (1992) Long-term microtine dynamics in north Fennoscandian tundra: the vole cycle and the lemming chaos. Ecography 15:226–236Google Scholar
  42. Oksanen L, Oksanen T, Lukkari A, Siren S (1987) The role of phenol-based inducible defense in the interaction between tundra populations of the vole Clethrionomys rufocanus and the dwarf shrub Vaccinium myrtillus. Oikos 50:371–380Google Scholar
  43. Oksanen T, Oksanen L, Norberg M (1992) Habitat use of small mustelids in north Fennoscandian tundra: a test of the hypothesis of patchy exploitation ecosystems. Ecography 15:237–244Google Scholar
  44. Pech RP, Sinclair ARE, Newsome AE, Catling PC (1992) Limits to predator regulation of rabbits in Australia: evidence from predator-removal experiments. Oecologia 89:102–112Google Scholar
  45. Sih A, Crowley P, McPeek M, Petranka J, Strohmeier K (1985) Predation, competition and prey communities: a review of field experiments. Annu Rev Ecol Syst 16:269–311Google Scholar
  46. Sinclair ARE (1989) Population regulation in animals. In: Cherrett JM (ed) Ecological concepts. Blackwell, Oxford, pp 197–241Google Scholar
  47. Steen H, Yoccoz NG, Ims RA (1990) Predators and small rodent cycles: an analysis of a 79-year time series of small rodent population fluctuations. Oikos 59:115–120Google Scholar
  48. Stenseth NC, Ims RA (1993) Population dynamics of lemmings: temporal and spatial variation — an introduction. In: Stenseth NC, Ims RA (eds) The biology of lemmings. Academic Press, London, pp 61–96Google Scholar
  49. Ylönen H (1989) Weasels Mustela nivalis suppress reproduction in cyclic bank voles Clethrionomys glareolus. Oikos 55:138–140Google Scholar
  50. Ylönen H, Viitala J, Mappes T (1991) How much do avian predators influence cyclic bank vole populations? An experiment during a peak year. Ann Zool Fenn 28:1–6Google Scholar

Copyright information

© Springer-Verlag 1995

Authors and Affiliations

  • Kai Norrdahl
    • 1
  • Erkki Korpimäki
    • 2
  1. 1.Department of Zoology, Division of EcologyUniversity of HelsinkiFinland
  2. 2.Laboratory of Ecological Zoology, Department of BiologyUniversity of TurkuTurkuFinland

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