Oecologia

, Volume 104, Issue 1, pp 112–121 | Cite as

Influence of size and density of browse patches on intake rates and foraging decisions of young moose and white-tailed deer

  • L. A. Shipley
  • D. E. Spalinger
Original Paper

Abstract

We examined the functional response and foraging behavior of young moose (Alces alces) and white-tailed deer (Odocoileus virginianus) relative to animal size and the size and distribution of browse patches. The animals were offered one, three, or nine stems of dormant red maple (Acer rubrum) in hand-assembled patches spaced 2.33, 7, 14, or 21 m apart along a runway. Moose took larger twig diameters and bites and had greater dry matter and digestible energy intake rates than did deer, but had lower cropping rates. Moose and deer travelled at similar velocities between patches and took similar numbers of bites per stem. We found that a model of intake rate, based on the mechanics of cropping, chewing, and encountering bites, effectively described the intake rate of moose and deer feeding in heterogeneous distributions of browses. As patch size and density declined, the animals walked faster between patches, cropped larger bites, and cropped more bites per stem, and hence, dry matter intake rates remained relatively constant. As is characteristic of many hardwood browse stems, however, potential digestible energy concentration of the red maple stems declined as the size and number of bites removed (i.e., stem diameter at point of clipping) by the animals increased. Therefore, the digestible energy content of the diet declined with decreasing patch size and density. Time spent foraging within a patch increased as patch size increased and as distance between patches increased, which qualitatively supported the marginal-value theorem. However, actual patch residence times for deer and moose exceeded those predicted by the marginal-value theorem (MVT) by approximately 250%. The difference between actual and predicted residence time may have been a result of (1) an unknown or complex gain function, (2) the artificial conditions of the experiments, or (3) assumptions of MVT that do not apply to herbivores.

Key words

Bite size Foraging behavior Herbivores Marginal-value theorem Patch 

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References

  1. Arditi R, Dacorogna B (1988) Optimal foraging on arbitrary food distributions and the definition of habitat patches. Am Nat 131:837–846Google Scholar
  2. Åström M, Lundberg P, Danell K (1990) Partial prey consumption by browsers: trees as patches. J Anim Ecol 59:287–300Google Scholar
  3. Belovsky GE (1986) Optimal foraging and community structure, implications for a guild of generalist grassland herbivores. Oecologia 70:35–52Google Scholar
  4. Black JL, Kenney PA (1984) Factors affecting diet selection by sheep. II. Height and density of pasture. Aust J Agric Res 35:551–563Google Scholar
  5. Bunnell FL, Gillingham MP (1985) Foraging behavior: dynamics of dining out. In: Hudson RJ, White RG (eds) Bioenergetics of wild herbivores. CRC Press, Boca Raton, pp 53–79Google Scholar
  6. Burlison AJ, Hodgson J, Illius AW (1991) Sward canopy structure and the bite dimension and bite weight of grazing sheep. Grass For Sci 46:29–38Google Scholar
  7. Charnov EL (1976) Optimal foraging: the marginal value theorem. Theor Popul Biol 9:129–136Google Scholar
  8. Cooper SM, Owen-Smith N (1986) Effects of plant spinescence on large mammalian herbivores. Oecologia 68:446–455Google Scholar
  9. Cowie RJ (1977) Optimal foraging of the great tit (Parus major). Nature 268:137–139Google Scholar
  10. Demment MW, Van Soest PJ (1985) A nutritional explanation for body-size patterns of ruminant herbivores. Am Nat 125:641–672Google Scholar
  11. Gillingham MP, Bunnell FL (1989) Effects of learning on food selection and searching behaviour of deer. Can J Zool 67:24–32Google Scholar
  12. Goering HK Van Soest PJ (1970) Forage fiber analysis (Agriculture Handbook No. 379). US Department of Agriculture, Washington D.C.Google Scholar
  13. Gross JE, Shipley LA, Hobbs NT, Spalinger DE, Wunder BA (1993) Foraging by herbivores in food-concentrated patches: tests of a mechanistic model of functional response. Ecology 74:778–791Google Scholar
  14. Hanley TA (1984) Habitat patches and their selection by wapiti and black-tailed deer in a coastal montane coniferous forest. J Appl Ecol 21:65–79Google Scholar
  15. Hjälten J, Danell K, Lundberg P (1993) Herbivore avoidance by association: vole and hare utilization of woody plants. Oikos 68:125–131Google Scholar
  16. Hodges CM (1981) Optimal foraging in bumblebees: hunting by expectation. Anim Behav 29:1166–1171Google Scholar
  17. Holling CS (1959) Some characteristics of simple types of predation and parasitism. Can Entomol 91:385–398Google Scholar
  18. Hubbert ME (1987) The effect of diet on energy partitioning in moose. MS Thesis, University of Alaska, FairbanksGoogle Scholar
  19. Jiang Z, Hudson RJ (1993) Optimal grazing of wapiti (Cervus elaphus) on grassland: patch and feeding station departure rules. Evol Ecol 7:488–498Google Scholar
  20. Laca EA, Demment M (1991) Herbivory: the dilemma of foraging in a spatially heterogeneous food environment. In: Palo T, Robbins CT (eds) Plant defenses against mammalian herbivores. CRC Press, Boca Raton, pp 29–44Google Scholar
  21. Laca EA, Distel RA, Griggs TC, Deo GP, Demment MW (1993) Field test of optimal foraging with cattle: the marginal value theorem successfully predicts patch selection and utilisation. In: XVII Proc Int Grassland Congr New Zealand and Queensland, February 1993, pp 709–710Google Scholar
  22. Langvatn R, Hanley TA (1993) Feeding-patch choice by red deer in relation to foraging efficiency: an experiment. Oecologia 95:164–170Google Scholar
  23. Lentner M, Bishop T (1986) Experimental design and analysis. Valley, Blacksburg, VirginiaGoogle Scholar
  24. Lundberg P (1988) Functional response of a small mammalian herbivore: the disc equation revisited. J Anim Ecol 57:999–1006Google Scholar
  25. MacArthur RH, Pianka ER (1966) On optimal use of a patchy environment. Am Nat 100:603–609Google Scholar
  26. Mould ED, Robbins CT (1981) Evaluation of detergent analysis in estimating nutritional value of browse. J Wildl Manage 45:937–947Google Scholar
  27. Palo RT, Bergström R, Danell K (1992) Digestibility, distribution of phenols, and fiber at different twig diameters of birch in winter. Implication for browsers. Oikos 65:450–454Google Scholar
  28. Penning PS, Parsons AJ, Orr RJ, Treacher TT (1991) Intake and behaviour responses by sheep to changes in sward characteristics under continuous stocking. Grass For Sci 46:15–28Google Scholar
  29. Pleasants JM (1989) Optimal foraging by nectarivores: a test of the marginal-value theorem. Am Nat 134:51–71Google Scholar
  30. Risenhoover KL (1987) Winter foraging strategies of moose in subarctic and boreal forest habitats. PhD diss, Michigan Technical University, HoughtonGoogle Scholar
  31. Robbins CT, Mole S, Hagerman AE, Hanley TA (1987) Role of tannins in defending plants against ruminants: reduction in dry matter digestibility. Ecology 68:1606–1615Google Scholar
  32. S≸ther BE, Andersen R (1990) Resource limitations in a generalist herbivore, the moose Alces alces: ecological constraints on behavioural decisions. Can J Zool 68:993–999Google Scholar
  33. SAS (1985) SAS user's guide: statistics, version 5 edn. SAS Institute, CaryGoogle Scholar
  34. Schwartz CC, Hubbert ME, Franzmann AW (1988) Energy requirements of adult moose for winter maintenance. J Wildl Manage 52:26–33Google Scholar
  35. Schwartz CC, Regelin WL, Franzmann AW (1988) Estimates of digestibility of birch, willow, and aspen mixtures in moose. J Wildl Manage 52:33–37Google Scholar
  36. Senft RL, Coughenour MB, Bailey DW, Rittenhouse LR, Sala OE, Swift DM (1987) Large herbivore foraging and ecological hierarchies. Bioscience 37:789–799Google Scholar
  37. Shipley LA, Spalinger DE (1992) Mechanics of browsing in dense food patches: effects of plant and animal morphology on intake rate. Can J Zool 70:1743–1752Google Scholar
  38. Shipley LA, Gross JE, Spalinger DE, Hobbs NT, Wunder BA (1994) The scaling of intake rate in mammalian herbivores. Am Nat 143:1055–1082Google Scholar
  39. Shively LA (1989) Mechanics of foraging behavior of boreal herbivores. MS thesis, University of Maine, OronoGoogle Scholar
  40. Spalinger DE, Hanley TA, Robbins CT (1988) Analysis of the functional response in foraging in the sitka black-tailed deer. Ecology 69:1166–1175Google Scholar
  41. Spalinger DE, Hobbs NT (1992) Mechanisms of foraging in mammalian herbivores: new models of functional response. Am Nat 140:325–348Google Scholar
  42. Stephens DW, Krebs JR (1986) Foraging theory. Princeton University Press, PrincetonGoogle Scholar
  43. Stobbs TH (1973) The effect of plant structure on the intake of tropical pastures. I. Variation in the bite size of grazing cattle. Aust J Agric Res 24:809–819Google Scholar
  44. Vivås HJ, S≸ther BE (1987) Interactions between a generalist herbivore, the moose Alces alces and its food resources: an experimental study of winter foraging behaviour in relation to browse availability. J Anim Ecol 56:509–520Google Scholar
  45. Vivås HJ, S≸ther BE, Andersen R (1991) Optimal twig-size selection of a generalist herbivore, the moose Alces alces: implications for plant-herbivore interactions. J Anim Ecol 60:395–408Google Scholar

Copyright information

© Springer-Verlag 1995

Authors and Affiliations

  • L. A. Shipley
    • 1
  • D. E. Spalinger
    • 1
  1. 1.Department of Wildlife ManagementUniversity of MaineOronoUSA

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