, Volume 60, Issue 2, pp 185–189 | Cite as

Diet shifts in moose due to predator avoidance

  • Joan Edwards
Original Papers


On Isle Royale, Michigan, moose cows which have calves show a different distribution and diet from solitary adults and yearling moose. Solitary adults and yearlings follow a feeding pattern predicted from the location of high nutrient plant growth. In the presence of wolves, they feed on the ridges of the main island, where they take advantage of plants that leaf early; only later in the season do they move to the small outlying islands where plant phenology is delayed by the cold water of Lake Superior. Cows with calves deviate sharply from this pattern. They remain on the wolf-free small islands throughout the growing season. While on the islands, cows with calves eat a poorer quality diet than other moose. They switch to eating high quality spring and summer foods later than other moose and they eat significantly fewer high preference shrubs and significantly more herbs and low preference shrubs than other moose.

This study suggests that in order to avoid predators, cows with calves sacrifice the high quality diet available on the main island. These data also suggest that the wolves not only affect prey numbers by direct kills but may also indirectly influence prey numbers by altering the diet of their prey. In this case, the reproductive cows, those individuals that contribute most directly to growth of the population, avoid predators but frequent poor feeding areas.


Quality Diet Predator Avoidance Main Island Plant Phenology Diet Shift 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Altmann M (1958) Social integrations of the moose calf. Anim Behav 6:155–159Google Scholar
  2. Amstrup SC, Beecham J (1976) Activity patterns of radio-collared black bears in Idaho. J Wildl Manage 40:340–348Google Scholar
  3. Arnold GW (1964) Factors within plant associations affecting the behavior and performance of grazing animals. In: Crisp DJ (ed) Grazing in terrestrial and marine environments. Blackwell Scientific Publications, Oxford, pp 133–154Google Scholar
  4. Belovsky GE (1978) Diet optimization in a generalist herbivore, the moose. Theor Popul Biol 14:105–134Google Scholar
  5. Belovsky GE, Jordan PA (1978) The time energy budget of a moose. Theor Popul Biol 14:76–104Google Scholar
  6. Blair RM, Epps EA (1967) Distribution of protein and phosphorus in spring growth of rusty blackhaw. J Wildl Manage 31:188–190Google Scholar
  7. Brown CA (1937) Ferns and flowering plants of Isle Royale, Michigan. US Government Printing Office, Washington, DCGoogle Scholar
  8. Burkholder BL (1959) Movements and behavior of a wolf pack in Alaska. J Wildl Manage 23:1–11Google Scholar
  9. Cowan IM (1947) The timber wolf in the Rocky Mountain National Parks of Canada. Can J Res 25:139–174Google Scholar
  10. Cooper WA (1913) The climax forest of Isle Royale, Lake Superior, and its development. J Bot Gaz 55:1–44Google Scholar
  11. Covich AP (1976) Analyzing shapes of foraging areas: some ecological and economic theories. Ann Rev Ecol Syst 7:235–257Google Scholar
  12. Duvigneaud P, Denaeyer-de-Smet S (1970) Biological cycling of minerals in temperate deciduous forests. In: Reichle DE (ed) Analysis of temperate forest ecosystems. Springer-Verlag, New York, pp 199–225Google Scholar
  13. Edwards J (1976) Learning to eat by following the mother in moose calves. Am Midl Nat 96:229–232Google Scholar
  14. Edwards J (1978) Moose-vegetation interactions at the northeastern end of Isle Royale National Park, Michigan. PhD Dissertation, University of Michigan, Ann ArborGoogle Scholar
  15. Fraenkel G (1953) The nutritional value of green plants for insects. In: Symposium of the 9th International Congress of Entomology, Amsterdam, 1951, pp 90–100Google Scholar
  16. Geist V (1963) On the behavior of the North American moose (Alces alces andersoni, Peterson 1950) in British Columbia. Behavior 20:377–416Google Scholar
  17. Goddard J (1970) Movements of moose in a heavily hunted area of Ontario. J Wildl Manage 34:439–445Google Scholar
  18. Grigal DF, Ohmann LF, Brander RB (1976) Seasonal dynamics of tall shrubs in Northeastern Minnesota: biomass and nutrient element changes. For Sci 22:195–208Google Scholar
  19. Houston DB (1974) Aspects of the social organization of moose. In: Geist V, Walther F (eds) The behavior of ungulates and its relation to management. I.U.C.N.N.R. publication, Morges, Switzerland, p 690–696Google Scholar
  20. Jordan PA, Shelton PC, Allen DL (1967) Numbers, turnover, and social structure of the Isle Royale wolf population. Am Zool 7:233–252Google Scholar
  21. Julander O, Robinette WL, Jones DA (1961) Relation of summer range condition to mule deer herd productivity. J Wildl Manage 25:54–60Google Scholar
  22. Kelsall JP (1968) The caribou. Queen's Printer, Ottawa, CanadaGoogle Scholar
  23. Klein DR (1965) Ecology of deer range in Alaska. Ecol Monogr 35:259–284Google Scholar
  24. Krebs JR, Erichsen JT, Webber ME (1977) Optimal prey selection in the great tit (Parus major). Anim Behav 25:30–38Google Scholar
  25. Kubota J (1974) Mineral composition of browse plants for moose. Nat Can 101:291–305Google Scholar
  26. Laycock WA, Price DA (1970) Factors influencing forage quality. USDA Misc Pub No 1147:37–47Google Scholar
  27. LeResche RE, Davis JL (1973) Importance of nonbrowse foods to moose in the Kenai Peninsula, Alaska. J Wildl Manage 37:279–287Google Scholar
  28. Linn RM (1957) The spruce-fir, maple-birch transition in Isle Royale National Park, Lake Superior, PhD Dissertation, Duke University, Durham, North CarolinaGoogle Scholar
  29. MacArthur RH (1972) Geographical Ecology. Harper and Row, New YorkGoogle Scholar
  30. Markgren G (1969) Reproduction of moose in Sweden. Viltrevy 6:127–299Google Scholar
  31. Mech LD (1966) The wolves of Isle Royale. Fauna of the National Parks of the United States Fauna Series 7. US Government Printing Office, Washington DCGoogle Scholar
  32. Mech DL (1977) Wolf-pack buffer zones as prey reservoirs. Science 198:320–321Google Scholar
  33. Moen AN (1978) Seasonal changes in heart rates, activity, metabolism, and forage intake of white-tailed deer. J Wildl Manage 42:715–738Google Scholar
  34. Oh HK, Sakai T, Jones MB, Longhurst WN (1967) Effect of various essential oils isolated from Douglas fir needles upon sheep and deer rumen microbial activity. Appl Microbiol 15:777–784Google Scholar
  35. Oldemeyer JL (1974) Nutritive value of moose forage. Nat Can 101:217–226Google Scholar
  36. Orians GH (1966) Food of nestling yellow-headed blackbirds, Caribou Parklands, British Columbia. Condor 68:321–327Google Scholar
  37. Peterson RL (1955) North American moose. University of Toronto Press, TorontoGoogle Scholar
  38. Peterson RO (1977) Wolf ecology and prey relationships on Isle Royale. National Park Service Scientific Monograph Series Number 11. US Government Printing Office, Washington DCGoogle Scholar
  39. Pielou EC (1974) Population and Community Ecology. Gordon and Breach Science Publishers, New YorkGoogle Scholar
  40. Pimlott DH (1959) Reproduction and productivity of Newfoundland moose. J Wildl Manage 23:381–401Google Scholar
  41. Pyke GH (1978) Optimal foraging: movement patterns of bumblebees between inflorescences. Theor Popul Biol 13:72–98Google Scholar
  42. Pyke GH, Pulliam HR, Charnov EL (1977) Optimal foraging: a selective review of theory and tests. Quart Rev Biol 52:137–154Google Scholar
  43. Robinette WL, Gashweiler JS, Jones DA, Crane HS (1955) Fertility of mule deer in Utah. J Wildl Manage 19:115–135Google Scholar
  44. Shoener TW (1969) Optimal size and specialization in constant and fluctuating environments: an energy-time approach. Brookhaven Symp Biol 22:103–114Google Scholar
  45. Schoener TW (1971) Theory of feeding strategies. Ann Rev Ecol Syst 2:369–404Google Scholar
  46. Steen E (1968) Some aspects of the nutrition of semi-domestic reindeer. Symp Zool Soc Lond 21:117–128Google Scholar
  47. Stringham SF (1974) Mother-infant relations in moose. Nat Can 101:325–369Google Scholar
  48. Swift RW (1948) Deer select most nutritious forages. J Wildl Manage 12:109–110Google Scholar
  49. Tamm CO (1951) Seasonal variation in composition of birch leaves. Physiol Plant 4:461–469Google Scholar
  50. Tew RK (1970) Seasonal variation in the nutrient content of aspen foliage. J Wildl Manage 34:475–478Google Scholar
  51. Werner EE, Hall DJ (1974) Optimal foraging and size selection of prey by the bluegill sunfish (Lepomis machrochirus). Ecology 55:1042–1052Google Scholar
  52. Wilson DS (1976) Deducing the energy available in the environment: an application of optimal foraging theory. Biotropica 8:96–103Google Scholar

Copyright information

© Springer-Verlag 1983

Authors and Affiliations

  • Joan Edwards
    • 1
  1. 1.Biology DepartmentWilliams CollegeWilliamstownUSA

Personalised recommendations