Does prey density predict characteristics of primiparity in a solitary and specialized predator, the Canada lynx (Lynx canadensis)?

Age at primiparity is a flexible life history trait that purportedly responds to changing population dynamics and variable resource abundance. We examined placental scars in yearling Canada lynx ( Lynx canadensis Kerr, 1792) from the island of Newfoundland and used pregnancy rates and litter sizes to indicate primiparity. We modelled these lynx productivity data with snowshoe hare ( Lepus americanus Erxleben, 1777) population attributes using seven multiple a priori competing hypotheses. Hare abundance showed peak, decline and increase phases and densities based on capture-mark-recapture estimates ranged from 0.11 to 1.19 hares ha -1 . Overall yearling pregnancy rate was 23.5% and the model with hare abundance fitted alone had the most support. However, surprisingly hare abundance explained little (6%) variation in yearling pregnancy rate. Mean (± SE) litter size was 3.51 ± 0.27. None of our covariate models provided unequivocal support for predicting yearling litter size. We s...