Data from: Forest structure provides the income for reproductive success in a southern population of Canada lynx

Understanding intrinsic and extrinsic drivers of reproductive success is
central to advancing animal ecology and characterizing critical habitat.
Unfortunately, much of the work examining drivers of reproductive success
is biased toward particular groups of organisms (e.g., colonial birds,
large herbivores, capital breeders). Long-lived mammalian carnivores that
are of conservation concern, solitary, and territorial present an
excellent situation to examine intrinsic and extrinsic drivers of
reproductive success, yet they have received little attention. Here, we
used a Canada lynx (Lynx canadensis) dataset, from the southern periphery
of their range, to determine if reproductive success in a solitary
carnivore was consistent with capital or income breeding. We radio-marked
and monitored 36 female Canada lynx for 98 lynx years. We evaluated how
maternal characteristics and indices of food supply (via forest structure)
in core areas influenced variation in body condition and reproductive
success. We characterized body condition as mass/length and reproductive
success as whether a female produced a litter of kittens for a given
breeding season. Consistent with life-history theory, we documented a
positive effect of maternal age on body condition and reproductive
success. In contrast to predictions of capital breeding, we observed no
effect of pre-pregnancy body condition on reproductive success in Canada
lynx. However, we demonstrated statistical effects of forest structure on
reproductive success in Canada lynx, consistent with predictions of income
breeding. The forest characteristics that defined high success included
(1) abundant and connected mature forest and (2) intermediate amounts of
small-diameter regenerating forest. These attributes are consistent with
providing abundant, temporally stable, and accessible prey resources
(i.e., snowshoe hares; Lepus americanus) for lynx and reinforce the
bottom-up mechanisms influencing Canada lynx populations. Collectively,
our results suggest that lynx on the southern range periphery exhibit an
income breeding strategy and that forest structure supplies the income
important for successful reproduction. More broadly, our insights advance
the understanding of carnivore ecology and serve as an important example
on integrating long-term field studies with ecological theory to advance
landscape management.