Elephant seal foraging dives do indeed track prey distribution, but temperature influences the distribution of prey: Reply to Boersch-Supan et al. (2012)

McIntyre et al. (2011a; Mar Ecol Prog Ser 441:257−272) illustrated a number of relationships between environmental variables and the dive behaviour of satellite-tracked southern elephant sealsMirounga leonina. One of these associations was that seals tended to increase their dive depths and spend less time at targeted dive depths when swimming in warmer waters. Boersch-Supan et al.’s (2012; Mar Ecol Prog Ser 461:293–298) comment on this study suggests that the link described between dive depths andin situtemperature is actually a link between dive depths and prey distribution. We do not dispute this assertion, having discussed this likelihood in McIntyre et al. (2011a). Boersch-Supan et al. (2012) further provide a number of criticisms, based partly on their observations of potential prey distributions within a comparatively small geographic area. We argue that their results are not directly comparable to those presented in McIntyre et al. (2011a) given the limited spatial overlap of the study areas and sparse, small-scale dataset presented. We further provide replies to technical comments by Boersch-Supan et al. (2012) pertaining to our data analyses.