Some polar bears, especially those forced ashore when the sea ice melts in summer, have been observed running on land in pursuit of terrestrial prey (e.g. Brook and Richardson, 2002; Iles et al., 2013 and references therein). Given their locomotive inefficiency and potential to overheat in warm weather (Øritsland, 1970; Øritsland and Lavigne, 1976; Best, 1982), it is unclear whether these more intensive pursuits can be energetically profitable (Lunn and Stirling, 1985; Iles et al., 2013). In the only examination of this issue thus far, Lunn and Stirling (1985) used a calculation based on Hurst et al. (1982a) to suggest that a 320 kg polar bear chasing a goose at 20 km/h for >12 s would expend more energy in the pursuit than could be obtained from consuming it. Despite the speed and mass specificity of that projection, many authors have used this threshold in evaluating observations of polar bears chasing various land-based prey [e.g. caribou, Rangifer tarandus (Brook and Richardson, 2002); barnacle geese, Branta leucopsis (Stempniewicz, 2006); thick-billed murres, Uria lomvia (Donaldson et al., 1995); lesser snow geese (Iles et al., 2013)] and questioned the energetic worth of the observed predatory behaviours.