Canadian Fur Bearer Cycles and Cree-Ojibwa Hunting and Trapping Practices

Hutchinson (1975) has recently suggested that the study of population cycles is one area of ecological inquiry where theory and data have not always interacted to produce satisfactory explanations. One difficulty may be that a major part of the data available, fur trade statistics, provides evidence of a different kind than has been, until recently, assumed. In this paper I have attempted to substantiate in qualified form a hypothesis presented by Weinstein (1977) and independently by Winterhalder (1977) pertinent to this difficulty. It states that cyclic or fluctuating pelt counts of boreal region species are partially a result of differential foraging by native trappers, and for many species are not directly indicative of population fluctuations. Three conditions necessary to this interpretation were established: (1) Hare were important in the diet of the Cree-Ojibwa, (2) they could be effectively and efficiently obtained when abundant, and (3) the quest for food-producing species, including hare, had priority to the native trapper because pelts could not generally be exchanged for food. Ethnohistorical evidence provides direct accounts of the postulated relationship. An optimal foraging model was briefly introduced to elaborate the hypothesis. This theory provides an appropriate framework for investigating this topic, and possibly also a key for retrieving population data from fur trade harvest statistics. It was shown that the differential foraging hypothesis is consistent with a number of observed properties of pelt-count cycles, including the apparent similarity in all respects except amplitude, between pelt-counts and actual population fluctuations in lynx and hare. The hypothesis suggested here is important for the statistical analysis of peltcount cycles, and it raises questions about the reality of population cycles which are inferred predominantly or solely from fur record data. Despite this there is ample evidence demonstrating population cycles for hare and lynx, cycles which presumably have correlative food-chain effects on other species, including humans.