"To assess if predation is causing low prey density, one needs to quantify the total response of predators to changing prey density. Conceptually, this response has been divided into two components: the numerical and the functional response. The numerical response summarizes changes in predator numbers with prey density, whereas the functional response describes how the number of prey consumed per predator varies with prey density."(478)

"In this paper, I review wolf (Canis lupus) and moose interactions over a broad spectrum of moose densities. The primary objective is to test empirically whether wolf predation can regulate moose numbers."(479)

"From 0 to 0.65 moose/km2, predation was strongly density dependent. Above 0.65 moose/km2, predation rate gradually declined. The numerical and functional response did not contribute equally to changes in predation rate. At low moose densities, the numerical response was the principal factor underlying density dependence."(483)

"The empirical data summarized above suggest that in the presence of a single predator, the wolf, moose would stabilize at approx. 1.3 moose/km2, compared to an equilibrium density of 2.0 moose/km2 with no predators…. If moose growth rate is reduced by only 5-10%, because of either a less productive habitat or a density-invariant predation rate by an alternate predator like grizzly or black bear, then a low-density equilibrium is predicted."(484)

"The rather weak depensatory nature of wolf predation (Fig. 7) probably precludes the formation of a high-density equilibrium for moose populations cohabiting with at least two species of predators, or in a relatively poor habitat. Considering that most moose populations cohabit with at least two species of predators in North America, it is not surprising to observe that lightly exploited moose populations are found almost without exception at low densities compared to KCC…. At high moose densities, wolves limit, but do not regulate, moose numbers."(485)