| Theberge, Gauthier | John B., David A. | Models of wolf-ungulate relationships: When is wolf control justified? | 1985 | Wildlife Society Bulletin 13:449-458 |
“... nutrition/climate is a pervasive ultimate factor even when ungulates may be limited by wolf predation as a proximate factor. Connolly (1978) commented that nutrition availability, frequently altered by climate, often was mentioned as the ultimate limiting factor in the studies he reviewed.” (p. 452)
“Ungulate populations may decrease due to either increased predation... or lowered nutrition/climate levels. Wolf predation alone has not caused rapid declines in ungulates in any mainland ecosystems...” (p. 453)
The authors developed a series of models that illustrate different interactions of an ungulate population with its nutrition/climate level* and predators. Two of these models describe situations in which wolf control may be justified and would result in higher ungulate numbers: (1) a stable ungulate population held below its potential nutrient/ climate level by wolves; and (2) a decreased ungulate population caused by increased predation, usually with an increased human kill added to the wolf kill. The authors also believe that under certain conditions when an ungulate population is at its nutrient/climate level, wolf control will only result in added mortality though increased starvation of ungulates.* - nutrition/climate level refers to the maximum number of ungulates that can be sustained by the available forage and climatic conditions.