Multiple equilibrium models (Haber 1977) combine the 2 

 other models and hold that predators are important at low 

 ungulate densities but that at high densities, ungulates 

 escape the influence of predators and are influenced by 

 density-dependent intraspecif ic competition for resources. 



Because density-dependent intraspecif ic competition for 

 resources has been assumed to be major factor regulating 

 ungulate populations, human predation (hunting) is often 

 neglected in studies of factors controlling populations. 

 Management theory usually assumes that hunting losses are 

 compensated for by decreased mortality and increased 

 reproduction and recruitment of young among survivors. 



Recently, some authors (Geist 1981, Ozoga et al . 1982) 

 have suggested that behavior may be more important than 

 previously realized in determining deer population size, 

 structure, and dynamics. However, these views have 

 subsequently received little attention or comment by others. 



The Concept of Carrying Capacity 



Because most applied management theory for ungulates is 

 based on the ungulate-habitat interaction model, a discussion 

 of population ecology and regulation necessarily includes 

 discussion of the carrying capacity concept. 



In general, "carrying capacity" refers to the number or 

 density of animals a given habitat/environment can support. 

 A good review of the concept, its use, and interpretation is 

 provided by Macnab (1985). The terminology and components 

 included in specific definitions vary widely, but 

 animal-vegetation (forage) interactions similar to those 

 underlying range-domestic livestock relationships and 

 livestock production pervade most interpretations applied to 

 deer and other wild ungulates. Thus, Macnab (1985) notes "For 

 range management, the density of cattle providing maximum 

 sustained production of beef is the carrying capacity of the 

 land." More generally, Caughley (1979) states "Carrying 

 capacity is the name we give to an equilibrium between animals 

 and vegetation, and we index the position of that equilibrium 

 by its characteristic density of animals." Such definitions 

 would also indicate or at least imply that carrying capacity 

 is a more or less finite entity, varying only in relation to 

 changes in vegetation/forage supplies induced by animal-plant 

 interactions . 



Alternatively, some theoretical definitions have 

 recognized that "carrying capacity" may be determined by many 

 factors and may vary considerably. Foote (1971), for example, 

 defined carrying capacity as "The sum of the environmental 

 factors which make a game range habitable," and further stated 



