Evolutionary Ecology

, Volume 11, Issue 6, pp 641–672 | Cite as

Optimal foraging and community structure: The allometry of herbivore food selection and competition

  • Gary E. Belovsky
Article

Abstract

I address the selection of plants with different characteristics by herbivores of different body sizes by incorporating allometric relationships for herbivore foraging into optimal foraging models developed for herbivores. Herbivores may use two criteria in maximizing their nutritional intake when confronted with a range of food resources: a minimum digestibility and a minimum cropping rate. Minimum digestibility should depend on plant chemical characteristics and minimum cropping rate should depend on the density of plant items and their size (mass). If herbivores do select for these plant characteristics, then herbivores of different body sizes should select different ranges of these characteristics due to allometric relationships in digestive physiology, cropping ability and nutritional demands. This selectivity follows a regular pattern such that a herbivore of each body size can exclusively utilize some plants, while it must share other plants with herbivores of other body sizes. I empirically test this hypothesis of herbivore diet selectivity and the pattern of resource use that it produces in the field and experimentally. The findings have important implications for competition among herbivores and their population and community ecology. Furthermore, the results may have general applicability to other types of foragers, with general implications for how biodiversity is influenced.

allometry competition herbivory optimal foraging 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Alexander, F. (1952) Some functions of the large intestine of the horse. Quart. J. Exp. Physiol. 37, 205–214.Google Scholar
  2. Alexander, F. (1963) Digestion of the horse. In Progress in Nutrition and Allied Sciences (D.P. Cuthbertson, ed.), pp. 259–268. Oliver and Boyd, Edinburgh.Google Scholar
  3. Allo, A.A., Oh, J.H., Longhurst, W.M. and Connolly, G.E. (1973) VFA production in the digestive systems of deer and sheep. J. Wildl. Manage. 37, 202–211.Google Scholar
  4. Arman, P. and Field, C.R. (1973) Digestion in the hippopotamus. E. Afr. Wildl. J. 11, 9–17.Google Scholar
  5. Bakken, G.S. and Gates, D.M. (1975) Heat-transfer analysis of animals: Some implications for field ecology, physiology, and evolution. In Perspectives in Biophysical Ecology (D. Gates and R.B. Schmerl, eds), pp. 347–364. Springer-Verlag, New York.Google Scholar
  6. Balch, C.C. and Campling, R.C. (1965) Rate of passage of digesta through the ruminant digestive tract. In Physiology of Digestion in the Ruminant (R.W. Dougherty, ed.), pp. 108–123. Butterworth, Washington, DC.Google Scholar
  7. Bell, R.H.V. (1970) The use of the herb layer by grazing ungulates in the Serengeti. In Animal Populations in Relation to Their Food Resources (A. Watson, ed.), pp. 111–123. Blackwell, Oxford.Google Scholar
  8. Bell, R.H.V. (1971) A grazing ecosystem in the Serengeti. Sci. Am. 225, 86–93.Google Scholar
  9. Belovsky, G.E. (1978) Diet optimization in a generalist herbivore: The moose. Theor. Pop. Biol. 14, 105–134.Google Scholar
  10. Belovsky, G.E. (1981a) Food plant selection by a generalist herbivore: The moose. Ecology 62, 1020–1030.Google Scholar
  11. Belovsky, G.E. (1981b) Optimal activity times and habitat choice of moose. Oecologia 48, 22–30.Google Scholar
  12. Belovsky, G.E. (1984a) Herbivore optimal foraging: A comparative test of three models. Am. Nat. 124, 97–115.Google Scholar
  13. Belovsky, G.E. (1984b) Snowshoe hare optimal foraging and its implications for population dynamics. Theor. Pop. Biol. 25, 235–264.Google Scholar
  14. Belovsky, G.E. (1984c) Summer diet optimization by beaver. Am. Midl. Nat. 111, 209–222.Google Scholar
  15. Belovsky, G.E. (1986a) Generalist herbivore foraging and its role in competitive interactions. Am. Zool. 25, 51–69.Google Scholar
  16. Belovsky, G.E. (1986b) Optimal foraging and community structure: Implications for a guild of generalist grassland herbivores. Oecologia 70, 35–52.Google Scholar
  17. Belovsky, G.E. (1987a) Extinction models and mammalian persistence. In Viable Populations for Conservation (M.E. Soulé, ed.), pp. 35–57. Cambridge University Press, Cambridge.Google Scholar
  18. Belovsky, G.E. (1987b) Foraging and optimal body size: An overview, new data and a test of alternative models. J. Theor. Biol. 129, 257–287.Google Scholar
  19. Belovsky, G.E. (1987c) Hunter-gatherer foraging: A linear programming approach. J. Anthropol. Arch. 6, 29–76.Google Scholar
  20. Belovsky, G.E. (1990a) How important are nutrient constraints in optimal foraging models or are spatial/temporal factors more important? In Behavioural Mechanisms of Food Selection (R.N. Hughes, ed.), pp. 255–278. Springer-Verlag, Berlin.Google Scholar
  21. Belovsky, G.E. (1990b) A reply to Hobbs. In Behavioural Mechanisms of Food Selection (R.N. Hughes, ed.), pp. 415–422. Springer-Verlag, Berlin.Google Scholar
  22. Belovsky, G.E. (1991) Insights for caribou/reindeer management using optimal foraging theory. Rangifer Special Issue No. 7, 7–23.Google Scholar
  23. Belovsky, G.E. (1994) How good must models and data be in ecology. Oecologia 100, 475–480.Google Scholar
  24. Belovsky, G.E. and Jordan, P.A. (1978) The time-energy budget of a moose. Theor. Pop. Biol. 14, 76–104.Google Scholar
  25. Belovsky, G.E. and Schmitz, O.J. (1991) Mammalian herbivore optimal foraging and the role of plant defenses. In Plant Chemical Defense and Mammalian Herbivory (R.T. Palo and C.T. Robbins, eds), pp. 1–28. CRC Press, Cincinnati, OH.Google Scholar
  26. Belovsky, G.E. and Schmitz, O.J. (1993) Owen-Smith's evaluation of herbivore foraging models: What is constraining? Evol. Ecol. 7, 525–529.Google Scholar
  27. Belovsky, G.E. and Schmitz, O.J. (1994) Plant defenses and optimal foraging by mammalian herbivores. J. Mamm. 75, 816–832.Google Scholar
  28. Belovsky, G.E. and Slade, J.B. (1986) Time budgets of grassland herbivores: Body size similarities. Oecologia 70, 53–62.Google Scholar
  29. Belovsky, G.E. and Slade, J.B. (1987) The role of plant distributions on herbivore diet choice: A comparison of wild and domestic herbivores. In Herbivore Nutrition Research: Second International Symposium on the Nutrition of Herbivores (M. Rose, ed.), pp. 87–88. Australian Society of Animal Production, Brisbane.Google Scholar
  30. Belovsky, G.E. and Slade, J.B. (1995) Dynamics of some Montana grasshopper populations: Relationships among weather, food abundance and intraspecific competition. Oecologia 101, 383–396.Google Scholar
  31. Belovsky, G.E., Ritchie, M.E. and Morehead, J. (1989) Foraging in complex environments: When prey availability varies over time and space. Theor. Pop. Biol. 36, 144–160.Google Scholar
  32. Belovsky, G.E., Schmitz, O.J., Slade, J.B. and Dawson, T.J. (1991) Effects of spines and thorns on Australian arid zone herbivores of different body masses. Oecologia 88, 521–528.Google Scholar
  33. Bergerud, A.T. and Russell, L. (1964) Evaluation of rumen food analysis for Newfoundland caribou. J. Wildl. Manage. 28, 809–814.Google Scholar
  34. Bernays, E.A. and Chapman, R.F. (1970a) Experiments to determine the basis of food selection by Chorthippus parallelus (Zetterstedt) (Orthoptera: Acrididae) in the field. J. Anim. Ecol. 39, 761–776.Google Scholar
  35. Bernays, E.A. and Chapman, R.F. (1970b) Food selection by Chorthippus parallelus (Zetterstedt) (Orthoptera: Acrididae) in the field. J. Anim. Ecol. 39, 383–394.Google Scholar
  36. Bernays, E.A. and Chapman, R.F. (1972) Meal size in nymphs of Locusta migratoria. Ent. Exp. & Appl. 15, 399–410.Google Scholar
  37. Bernays, E.A. and Chapman, R.F. (1973) The role of food plants in the survival and development of Chortoicetes terminifera (Walker) under drought conditions. Aust. J. Zool. 21, 575–592.Google Scholar
  38. Berwick, S.H. (1968) Observations on the decline of the Rock Creek, Montana, population of bighorn sheep. Unpublished thesis, University of Montana, Missoula, MT.Google Scholar
  39. Bookhout, T.A. (1959) Reingestion by the snowshoe hare. J. Mamm. 40, 250.Google Scholar
  40. Brown, J.H. (1995) Macroecology. University of Chicago Press, Chicago, IL.Google Scholar
  41. Burt, W.H. and Grossenheider, R.P. (1964) A Field Guide to the Mammals. Houghton Mifflin, Boston, MA.Google Scholar
  42. Buss, I.O. (1961) Some observations on food habits and behavior of the African elephant. J. Wildl. Manage. 25, 131–148.Google Scholar
  43. Calder, W.A. (1984) Size, Function, and Life History. Harvard University Press, Cambridge, MA.Google Scholar
  44. Campling, R.C., Filer, M. and Balch, C.C. (1961) Factors affecting the voluntary intake of food by cows 2. The relationship between the voluntary intake of roughages, the amount of digesta in the reticulo-rumen, and the rate of disappearance of digesta from the alimentary tract. Br. J. Nutr. 15, 531–540.Google Scholar
  45. Chapman, R.F. (1957) Observations on the feeding of adults of the red locust (Nomadacris septemfacsiata). Br. J. Anim. Behav. 5, 60–75.Google Scholar
  46. Chase, J.M. (1996a) Differential competitive interactions and the included niche: An experimental analysis with grasshoppers. Oikos 76, 103–112.Google Scholar
  47. Chase, J.M. (1996b) Varying resource abundances and competitive dynamics. Am. Nat. 143, 514–527.Google Scholar
  48. Chase, J.M. and Belovsky, G.E. (1994) Experimental evidence for the included niche. Am. Nat. 143, 514–527.Google Scholar
  49. Clough, C. and Hassom, A.G. (1970) A quantitative study of the daily activity of the warthog in Queen Elizabeth National Park, Uganda. E. Afr. Wildl. J. 8, 19–24.Google Scholar
  50. Cork, S.J. (1994) Digestive constraints on dietary scope in small and moderately-small mammals: How much do we really understand? In The Digestive System in Mammals: Food, Form and Function (D.J. Chivers and P. Langer, eds), pp. 337–369. Cambridge University Press, Cambridge.Google Scholar
  51. Dade, W.B., Jumars, P.A. and Penry, D.L. (1990) Supply-side optimization: Maximizing absorptive rates. In Behavioural Mechanisms of Food Selection (R.N. Hughes, ed.), pp. 531–556. Springer-Verlag, Heidelberg.Google Scholar
  52. Dean, R.E., Strickland, W.D., Newman, A.L., Thorne, E.T. and Hepworth, W.G. (1975) Reticulo-rumen characteristics of malnourished mule deer. J. Wildl. Manage. 39, 601–604.Google Scholar
  53. Demment, M.W. (1982) The scaling of ruminoreticulum size with body weight in East African ungulates. Afr. J. Ecol. 20, 43–47.Google Scholar
  54. Demment, M.W. and Van Soest, P.J. (1985) A nutritional explanation for body size patterns of ruminant and nonruminant herbivores. Am. Nat. 125, 641–672.Google Scholar
  55. Dexter, R.W. (1959) Another record of coprophagy by the cottontail. J. Mamm. 40, 250–251.Google Scholar
  56. Dorst, J. and Dandelot, P. (1969) A Field Guide to the Larger Mammals of Africa. Houghton Mifflin, Boston, MA.Google Scholar
  57. Eddy, T.A. (1961) Foods and feeding of the collared peccary in southern Utah. J. Wildl. Manage. 25, 248–257.Google Scholar
  58. Egorov, O.V. (1967) Wild Ungulates of Yakutia. Israel Program for Scientific Translations, Jerusalem.Google Scholar
  59. Eley, J. (1970) Stomach contents, weights and volumes of Cape Hare. E. Afr. Wildl. J. 8, 270.Google Scholar
  60. Emlen, J.M. (1966) The role of time and energy in food preference. Am. Nat. 100, 611–617.Google Scholar
  61. Fitch, H.S. (1948) Ecology of the California ground squirrel on grazing lands. Am. Midl. Nat. 39, 513–551.Google Scholar
  62. Fitzgerald, J.P. and Lechleitner, R.R. (1974) Observations on the biology of Gunnison's prairie dog in Central Colorado. Am. Midl. Nat. 92, 146–163.Google Scholar
  63. Flux, J.E.C. (1971) Life history of the mountain hare in north-east Scotland. J. Zool. 161, 75–123.Google Scholar
  64. Gates, D.M. (1980) Biophysical Ecology. Springer-Verlag, New York.Google Scholar
  65. Geist, V. (1974) On the relationship of social evolution and ecology in ungulates. Am. Zool. 14, 205–220.Google Scholar
  66. Gelting, P. (1937) Studies on the food of the East Greenland ptarmigan, especially in its relation to vegetation and snow cover. Medd. on Greenland 116, 101–196.Google Scholar
  67. Gill, J. and Bieguszewski, H. (1960) The passage time of food through the digestive tract of the nutria, Myocaster coypus, 1782. Acta Ther. 4, 11–25.Google Scholar
  68. Golley, F.B. (1960) Anatomy of the digestive tract of Microtus. J. Mamm. 41, 89–99.Google Scholar
  69. Grantham, O.K., Moorhead, D.L. and Willig, M.R. (1995) Foraging strategy of the giant ramshorn snail, Marisa cornuarietis: An interpretive model. Oikos 72, 333–342.Google Scholar
  70. Grinnel, J., Dixon, J.S. and Linsdale, J.M. (1937) Fur Bearing Mammals of California. University of California Press, Berkeley, CA.Google Scholar
  71. Gross, J.E., Shipley, L.A., Hobbs, N.T., Spalinger, D.E. and Wunder, B.A. (1993) Functional response of herbivores in food-concentrated patches: Tests of a mechanistic model. Ecology 74, 778–791.Google Scholar
  72. Gwynne, M.D. and Bell, R.H.V. (1968) Selection of vegetation components by grazing ungulates in the Serengeti National Park. Nature 220, 390–393.Google Scholar
  73. Hainlein, G.F.W., Smith, R.C. and Yoon, Y.M. (1966) Determination of the fecal excretion rate of horses with chromic oxide. J. Anim. Sci. 25, 1091–1095.Google Scholar
  74. Hamilton, W.J., Jr (1955) Coprophagy in the swamp rabbit. J. Mamm. 36, 303–304.Google Scholar
  75. Hamilton, W.J., Jr (1934) The life history of the rufescen woodchuck, Marmota monax. Annals of the Carnegie Museum 23, 85–178.Google Scholar
  76. Hemmingsen, A.M. (1960) Energy metabolism as related to body size and respiratory surfaces, and its evolution. Reports of the Steno Memorial Hospital and Nordinsk Insulin Laboratorium 9, 6–110.Google Scholar
  77. Hewson, R. (1962) Food and feeding habits of the mountain hare. Proc. Zool. Soc. Lond. 139, 515–526.Google Scholar
  78. Hintz, H.F. and Loy, R.G. (1966) Effects of pelleting on the nutritive value of horse rations. J. Anim. Sci. 25, 1059–1062.Google Scholar
  79. Hobbs, N.T. (1990) Diet selection by generalist herbivores: A test of the linear programming model. In Behavioural Mechanisms of Food Selection (R.N. Hughes, ed.), pp. 395–413. Springer-Verlag, Berlin.Google Scholar
  80. Hobbs, N.T. and Swift, D.M. (1985) Estimates of habitat carrying capacity incorporating explicit nutritional constraints. J. Wildl. Manage. 49, 814–822.Google Scholar
  81. Holling, C.S. (1992) Cross-scale morphology, geometry, and dynamics of ecosystems. Ecol. Monogr. 62, 447–502.Google Scholar
  82. Hoppe, P.P. (1977) Comparison of voluntary food and water consumption and digestion in Kirk's dikdik and suni. E. Afr. Wildl. J. 15, 41–48.Google Scholar
  83. Huggard, D.J. (1994) A linear programming model of herbivore foraging: Imprecise, yet successful? Oecologia 100, 470–474.Google Scholar
  84. Hughes, R.N. (ed.) (1990) Behavioral Mechanisms of Food Selection. Springer-Verlag, Berlin.Google Scholar
  85. Hungate, R.E., Phillips, G.O., McGregor, A., Hungate, D.P. and Buechner, H.E. (1959) Microbial fermentation in certain mammals. Science 130, 1192–1194.Google Scholar
  86. Hutchinson, G.E. (1959) Homage to Santa Rosalia or why are there so many kinds of animals? Am. Nat. 93, 145–159.Google Scholar
  87. Illius, A.W. and Gordon, I.J. (1987) The allometry of food intake in grazing ruminants. J. Anim. Ecol. 56, 989–999.Google Scholar
  88. Illius, A.W. and Gordon, I.J. (1990) Constraints on diet selection and foraging behaviour in mammalian herbivores. In Behavioural Mechanisms of Food Selection (R.N. Hughes, ed.), pp. 369–393. Springer-Verlag, Berlin.Google Scholar
  89. Illius, A.W. and Gordon, I.J. (1992) Modelling the nutritional ecology of ungulate herbivores: Evolution of body size and competitive interactions. Oecologia 89, 428–434.Google Scholar
  90. Janis, C.M. (1976) The evolutionary strategy of the Equidae and the origins of rumen and caecal digestion. Evolution 30, 757–774.Google Scholar
  91. Jarman, P.J. (1974) The social organization of antelope in relation to their ecology. Behaviour 48, 215–267.Google Scholar
  92. Jarman, P.J. and Sinclair, A.R.E. (1979) Feeding strategy and the patterning of resource partitioning in ungulates. In Serengeti: Dynamics of an Ecosystem (A.R.E. Sinclair and M. Norton-Griffiths, eds), pp. 130–163. University of Chicago Press, Chicago, IL.Google Scholar
  93. Johnson, D.R. and Maxwell, M.H. (1966) Energy dynamics of Colorado pikas. Ecology 47, 1059–1061.Google Scholar
  94. Johnson, J.L. and McBee, R.H. (1967) The porcupine cecal fermentation. J. Nutr. 91, 540–546.Google Scholar
  95. Jonkel, C.J. and Greer, K.R. (1963) Fall food habits of spruce grouse in northwest Montana. J. Wildl. Manage. 27, 593–596.Google Scholar
  96. Karasov, W.H. and Diamond, J.M. (1985) Digestive adaptations for fueling the cost of endothermy. Science 228, 202–204.Google Scholar
  97. Kleiber, M. (1961) The Fire of Life. John Wiley, New York.Google Scholar
  98. Kostelecka-Myrcha, A. and Myrcha, A. (1964) The rate of passage of foodstuffs through the alimentary tracts of certain Microtidae under laboratory conditions. Acta Ther. 9, 37–52.Google Scholar
  99. Lamprey, H.F. (1963) Ecological separation of the large mammal species in the Tarangire Game Reserve, Tanganyika. E. Afr. Wildl. J. 1, 63–92.Google Scholar
  100. Larter, N.C. (1992) Forage fiber analyses: A comparison of two techniques. Wildl. Res. 19, 289–293.Google Scholar
  101. Laws, R.M. and Parker, I.S.C. (1968) Recent studies on elephant populations in East Africa. Symp. Zool. Soc. Lond. 21, 319–359.Google Scholar
  102. Ledger, H.P. and Smith, N.S. (1964) The carcass and body composition of the Uganda Kob. J. Wildl. Manage. 28, 827–839.Google Scholar
  103. Lee, C. and Horvath, D.J. (1969) Management of meadow vole (Microtus pennsylvanicus) (abstract). J. Anim. Sci. 27, 1517.Google Scholar
  104. Leuthold, W. (1977) African Ungulates: A Comparative Review of Their Ethology and Behavioral Ecology. Springer-Verlag, Berlin.Google Scholar
  105. Longhurst, W.M. (1944) Observations on the ecology of the Gunnison prairie dog in Colorado. J. Mamm. 25, 24–36.Google Scholar
  106. MacArthur, R.H. and Pianka, E.R. (1966) On optimal use of a patchy environment. Am. Nat. 100, 603–609.Google Scholar
  107. Maloiy, G.M.O. and Kay, R.N.B. (1971) A comparison of digestion in red deer and sheep under controlled conditions. Quart. J. Exp. Physiol. 56, 257–266.Google Scholar
  108. Martinez del Rio, C., Cork, S.J. and Karasov, W.H. (1994) Modelling gut function: An introduction. In The Digestive System in Mammals: Food, Form and Function (D.J. Chivers and P. Langer, eds), pp. 25–53. Cambridge University Press, Cambridge.Google Scholar
  109. Mautz, W.W. and Petrides, G.A. (1971) Food passage rate in the white-tailed deer. J. Wildl. Manage. 35, 723–731.Google Scholar
  110. Maynard Smith, J. (1978) Optimization theory in evolution. Ann. Rev. Ecol. Syst. 9, 31–56.Google Scholar
  111. McBee, R.H. (1971) Significance of intestinal microflora in herbivory. Ann. Rev. Ecol. Syst. 2, 165–176.Google Scholar
  112. McMahon, T. (1973) Size and shape in biology. Science 179, 1201–1204.Google Scholar
  113. McMahon, T.A. and Bonner, J.T. (1983) On Size and Life. Scientific American Books, New York.Google Scholar
  114. Meagher, M.M. (1973) The Bison of Yellowstone National Park. Government Printing Office, Washington, DC.Google Scholar
  115. Milne, J.A., MacRae, J.C., Spence, A.M. and Wilson, S. (1976) Intake and digestion of hill-land vegetation by the red deer and the sheep. Nature 263, 763–764.Google Scholar
  116. Monteith, J.L. (1973) Principles of Environmental Physics. Elsevier, New York.Google Scholar
  117. Nagy, J.G. and Regelin, W.L. (1975) Comparison of three deer species. J. Wildl. Manage. 39, 621–624.Google Scholar
  118. Nagy, K.A. (1973) Behavior, diet and reproduction in a desert lizard, Sauromalus obesus. Copeia 1973(1), 93–102.Google Scholar
  119. Nonacs, P. and Dill, L.M. (1993) Is satisficing an alternative to optimal foraging theory. Oikos 67, 371–375.Google Scholar
  120. O'Gara, B.W. (1970) Derivation of whole weight for the pronghorn. J. Wildl. Manage. 34, 470–472.Google Scholar
  121. Owen-Smith, N. (1993) Evaluating optimal diet models for an African browsing ruminant, the kudu: How constraining are the assumed constraints? Evol. Ecol. 7, 499–524.Google Scholar
  122. Owen-Smith, N. (1996) Circularity in linear programming models of optimal diet. Oecologia 108, 259–261.Google Scholar
  123. Owen-Smith, R.N. (1988) Megaherbivores: The Influence of Very Large Body Size on Ecology. Cambridge University Press, Cambridge.Google Scholar
  124. Parker, G.R. (1977) Morphology, reproduction, diet, and behavior of the arctic hare (Lepus arcticus monstrabilis) on Axel Heiberg Island, Northwest Territories. Can. Field-Nat. 91, 8–18.Google Scholar
  125. Pendergast, B.A. and Boag, D.A. (1970) Seasonal changes in diet of spruce grouse in central Alberta. J. Wildl. Manage. 34, 605–611.Google Scholar
  126. Penry, D.L. and Jumars, P.A. (1986) Chemical reactor analysis and optimal digestion theory. Bioscience 36, 310–315.Google Scholar
  127. Penry, D.L. and Jumars, P.A. (1987) Modeling animal guts as chemical reactors. Am. Nat. 129, 69–96.Google Scholar
  128. Peters, R.H. (1983) The Ecological Implications of Body Size. Cambridge University Press, Cambridge.Google Scholar
  129. Peters, R.H. (1991) A Critique for Ecology. Cambridge University Press, Cambridge.Google Scholar
  130. Peters, S.S. (1958) Food habits of the Newfoundland willow ptarmigan. J. Wildl. Manage. 22, 384–394.Google Scholar
  131. Pierce, G.J. and Ollason, J.G. (1987) Eight reasons why optimal foraging theory is a complete waste of time. Oikos 49, 111–118.Google Scholar
  132. Prins, R.A. and Geelen, M.J.H. (1971) Rumen characteristics of red deer, fallow deer, and roe deer. J. Wildl. Manage. 35, 673–680.Google Scholar
  133. Ritzman, E.G. and Benedict, F.G. (1938) Nutritional Physiology of the Adult Ruminant. Carnegie Institute, Washington, DC.Google Scholar
  134. Rosenzweig, M.L. (1981) A theory of habitat selection. Ecology 62, 327–335.Google Scholar
  135. Rosenzweig, M.L. (1995) Species Diversity in Space and Time. Cambridge University Press, Cambridge.Google Scholar
  136. Schaeffer, A.L., Young, B.A. and Chimwano, A.M. (1978) Ration digestion and retention times of digesta in domestic cattle (Bos taurus), American bison (Bison bison), and Tibetan yak (Bos grunniens). Can. J. Zool. 56, 2355–2358.Google Scholar
  137. Schmidt-Nielsen, K. (1975) Animal Physiology: Adaptation and Environment. Cambridge University Press, Cambridge.Google Scholar
  138. Schmitz, O.J. (1991) Thermal constraints and optimization of winter feeding and habitat choice in white-tailed deer. Holarctic Ecol. 14, 104–111.Google Scholar
  139. Schmitz, O.J. and Ritchie, M.E. (1991) Optimal diet selection with variable nutrient intake: Balancing reproduction with risk of starvation. Theor. Pop. Biol. 39, 100–114.Google Scholar
  140. Schoener, T.W. (1969a) Models of optimal size for solitary predators. Am. Nat. 103, 277–313.Google Scholar
  141. Schoener, T.W. (1969b) Optimal size and specialization in constant and fluctuating environments: An energy-time approach. Brookhaven Symp. Biol. 22, 103–114.Google Scholar
  142. Schoener, T.W. (1971) Theory of feeding strategies. Ann. Rev. Ecol. Syst. 2, 369–404.Google Scholar
  143. Schoener, T.W. (1974) Competition and the form of habitat shift. Theor. Pop. Biol. 6, 265–307.Google Scholar
  144. Schoener, T.W. (1975) Presence and absence of habitat shift in some widespread lizard species. Ecol. Monogr. 45, 233–258.Google Scholar
  145. Schoener, T.W. (1986) Mechanistic approaches to community ecology: A new reductionism. Am. Zool. 26, 70–104.Google Scholar
  146. Schoonveld, G.G., Nagy, J.G. and Bailey, J.A. (1974) Capability of mule deer to utilize fibrous alfalfa diets. J. Wildl. Manage. 38, 823–829.Google Scholar
  147. Shelford, V.E. (1963) The Ecology of North America. University of Illinois Press, Urbana, IL.Google Scholar
  148. Shipley, L.A., Gross, J.E., Spalinger, D.E., Hobbs, N.T. and Wunder, B.A. (1994) The scaling of intake rate in mammalian herbivores. Am. Nat. 143, 1055–1082.Google Scholar
  149. Short, H.L. (1963) Rumen fermentations in deer. J. Wildl. Manage. 27, 184–195.Google Scholar
  150. Short, H.L. (1964) Postnatal stomach development of white-tailed deer. J. Wildl. Manage. 28, 445–458.Google Scholar
  151. Short, H.L., Medin, D.E. and Anderson, A.E. (1965) Ruminoreticular characteristics of mule deer. J. Mamm. 46, 196–199.Google Scholar
  152. Short, H.L., Medin, D.E. and Anderson, A.E. (1966) Seasonal variations in volatile fatty acids in the rumen of mule deer. J. Wildl. Manage. 30, 466–470.Google Scholar
  153. Short, H.L., Remmenga, E.E. and Boyd, C.E. (1969) Variations in ruminoreticular contents of white-tailed deer. J. Wildl. Manage. 33, 187–191.Google Scholar
  154. Spalinger, D.E. and Hobbs, N.T. (1992) Mechanisms of foraging in mammalian herbivores: New models of functional response. Am. Nat. 140, 325–348.Google Scholar
  155. Staines, B.W. (1976) Experiments with rumen-cannulated red deer to evaluate rumen analyses. J. Wildl. Manage. 40, 371–373.Google Scholar
  156. Stephens, D.W. and Krebs, J.R. (1986) Foraging Theory. Princeton University Press, Princeton, NJ.Google Scholar
  157. Stewart, D.R.M. (1967) Analysis of plant epidermis in faeces: A technique for studying the food preferences of grazing herbivores. J. Appl. Ecol. 4, 83–111.Google Scholar
  158. Storr, G.M. (1963) Estimation of dry-matter intake in wild herbivores. Nature 197, 307–308.Google Scholar
  159. Storr, G.M. (1964) Studies on marsupial nutrition. Aust. J. Biol. Sci. 17, 469–481.Google Scholar
  160. Swenk, M.H. and Silko, L.F. (1938) Late autumn food of the sharp-tailed grouse in western Nebraska. J. Wildl. Manage. 2, 184–189.Google Scholar
  161. Tileston, J.V. and Lechleitner, R.R. (1966) Some comparisons of the black-tailed and white-tailed prairie dogs in North-Central Colorado. Am. Midl. Nat. 75, 292–317.Google Scholar
  162. Vander Noot, G.W., Symons, L., Lydman, R. and Fonnerbeck, P. (1967) Rate of passage of various feed stuffs through the digestive tract of horses. J. Anim. Sci. 26, 1309–1311.Google Scholar
  163. Van Hoven, W., Prins, R.A. and Lankhorst, A. (1981) Fermentative digestion in the African elephant. S. Afr. J. Wild. Res. 11, 78–86.Google Scholar
  164. Vesey-Fitzgerald, D.F. (1960) Grazing succession among East African game animals. J. Mamm. 41, 161–172.Google Scholar
  165. Walker, J. and Farley, J.S. (1968) Winter food of Irish hares in County Antrim, Northern Ireland. J. Mamm. 49, 783–785.Google Scholar
  166. Ward, D. (1992) The role of satisficing in foraging theory. Oikos 63, 312–317.Google Scholar
  167. Ward, D. (1993) Foraging theory, like all other fields of science, needs multiple working hypotheses. Oikos 67, 376–378.Google Scholar
  168. Watson, A. (1964) The food of ptarmigan in Scotland. Scot. Natur. 71, 60–66.Google Scholar
  169. White, R.G. and Trudell, J. (1980a) Habitat preference and forage consumption by reindeer and caribou near Atkasook, Alaska. Arctic and Alpine Res. 12, 511–529.Google Scholar
  170. White, R.G. and Trudell, J. (1980b) Patterns of herbivory and nutrient intake of reindeer grazing tundra vegetation. In Proceedings of the 2nd International Reindeer/Caribou Symposium, 1979, Roros, Norway (E. Reimers, E. Gaare and S. Skjenneberg, eds), pp. 180–195. Direktoratet for vilt og ferskvannsfisk, Trondheim.Google Scholar
  171. Wilkinson, L., Hill, M.A., Welna, J.P. and Birkenbeuel, G.K. (1992) SYSTAT for Windows: Statistics. SYSTAT, Evanston, IL.Google Scholar
  172. Yang, Y. and Joern, A. (1994) Gut size changes in relation to variable food quality and body size in grasshoppers. Funct. Ecol. 8, 36–45.Google Scholar

Copyright information

© Chapman and Hall 1997

Authors and Affiliations

  • Gary E. Belovsky
    • 1
  1. 1.Department of Fisheries and Wildlife and Ecology CenterUtah State UniversityLoganUSA

Personalised recommendations