Polar bears normally use the sea ice as a platform to catch marine prey, particularly ringed seals (Pusa hispida), and accumulate a majority of their annual fat reserves from consuming seal pups in spring (e.g. Stirling and Øritsland, 1995). In more southern polar bear populations, it is thought that this energy store helps to sustain the bears during the ice-free period each summer (e.g. Stirling and Derocher, 1993; Regehr et al., 2007). With warmer temperatures leading to earlier sea ice break-up, access to this energy-rich spring seal diet may become limited, potentially forcing the bears to expend energy seeking land-based food to compensate for energy deficits (e.g. Stirling and Derocher, 2012; Gormezano and Rockwell, 2013a, 2015; Lunn et al., 2016). Any increased effort to obtain food is of concern because polar bears are considered inefficient at walking (Øritsland et al., 1976; Best 1982; Hurst et al., 1982a,b), exhibiting higher rates of oxygen consumption with increased walking speed than predicted for mammals of their size (Taylor et al., 1970; Fedak and Seeherman, 1979). The higher rates of energy use have been attributed to their morphology, particularly their large, heavy limbs (Øritsland et al., 1976; Hurst et al., 1982a,b), a characteristic shared by male lions that likewise have relatively high costs of locomotion (Chassin et al., 1976). Despite these energetic limitations, polar bears are known to walk long distances in search of prey on sea ice and land (e.g. Born et al., 1997; Amstrup et al., 2000; Parks et al., 2006; Anderson et al., 2008; Rockwell et al., 2011) but generally use more energy-conserving stalking or ‘still-hunting’ techniques to capture seals and other marine mammals on the sea ice (e.g. Stirling, 1974; Smith, 1980).