Wolves live in territorial family groups that cooperate to capture prey, raise young, and defend resources from competitors (Mech 1970). Wolves have a brief life history relative to other large carnivores, including early first reproduction, high fecundity, rapid development, and relatively short lifespans. The basic social unit of wolf populations is the mated pair and their offspring (Mech 1970). Due to delayed dispersal, wolf packs typically consist of multiple age and sex class compositions. Wolves are true cooperative breeders, with the care of offspring performed by both parents, as well as by other pack members. Wolves are sexually dimorphic (males and females have different size ranges), with males about 16-24% larger than females (MacNulty et al. 2009a), and have a multi-year growth pattern (MacNulty et al. 2009a, Stahler et al. 2013). Differences in body size between males and females are presumably shaped by selection pressures related to their respective reproductive strategies and roles in hunting and territoriality.