Estimation of habitat suitability for the southern form of the short‐finned pilot whale (<i><scp>G</scp>lobicephala macrorhynchus</i>) in the<scp>N</scp>orth<scp>P</scp>acific

Abstract Habitat models were developed from dedicated sighting survey data collected during summers between 1983 and 2006 in the N orth P acific O cean. Our aim was to examine the distribution pattern of the southern form of the short‐finned pilot whale ( G lobicephala macrorhynchus ) in relation to the physical environment. We tested two different types of analytical procedures for habitat estimation: generalized linear models ( GLM s) and ecological niche factor analysis ( ENFA ). The area under the receiver operating characteristic curve and the B oyce index suggested that GLM defined the core habitat well, whereas ENFA estimated the suitable habitat more correctly. These models indicated the core habitat within the subtropical gyre. Among the environmental variables used to construct the habitat models, the temperature at a depth of 200 m contributed most to both GLM and ENFA . This corresponds to the fact that the species mainly feeds on mesopelagic prey and that the axis of the K uroshio C urrent, in the northwestern part of the subtropical gyre, is characterized by its temperature at 200 m. Habitat suitability in the coastal waters off southern J apan also correlated with the K uroshio meander patterns. Thus, the southern form of the short‐finned pilot whale appears to be particularly well adapted to the ecosystem of the N orth P acific subtropical gyre.