Robin W. Baird and Pam J. Stacey
Canadian Journal of Zoology 66:2582-2585. 1988.
Patterns of pigmentation of the post dorsal fin patch, or saddle
patch, were analyzed from photographs of 372 resident and 99 transient
killer whales (Orincus orca) from British Columbia, Alaska,
and Washington State. Of the five types of saddle patch analyzed, all
were observed on residents, but only two occurred on transients.
Differences in saddle patch shapes were independent of age and sex.
Saddle patch pigmentation patterns were similar among clans within a
community. Pigmentation patterns differed significantly between the
resident and transient forms, between northern and southern residents,
between northern and Alaskan residents, and between southern and
Alaskan residents. As the saddle patch shape may be heritable to a
large degree, these differences suggest genetic isolation of the
populations. If so, this technique may be used to delineate stocks of
killer whales from other areas.
Return to
homepage of Robin W. Baird