Association of PCFG gray whales on migration

We found that PCFG whales often migrated together based on a review of identification photographs of migrating gray whales encountered by whale watch naturalists in Southern California operating primarily out of Santa Barbara and Long Beach 2013-15. We identified potential PCFG gray whales on migration and confirmed this by matching all whales associated in a group containing a suspected PCFG whale to Cascadia’s catalog. PCFG whales were identified on 21 occasions from as early in the season as 22 November to as late as 18 March. In 15 of 21 cases, multiple animals were reported to be in the group and in most of these (9) multiple PCFG whales were present in the group including five cases involving three to five PCFG whales. Associated PCFG whales occurred in both the southbound and northbound migrations though they were more commonly associated southbound. Of the 27 PCFG whales with known sexes identified on migration, 15 were females and 11 males and in groups with multiple animals of known sex, four of six groups contained animals of mixed sexes. This continued association of PCFG whales on both northbound and southbound migration raises the potential these animals associate on the winter breeding grounds as well and confirms indications that Western gray whales may migrate together as well. This increases the chances for breeding occurring within feeding area groupings even when animals migrate to a mixed wintering area


Calambokidis, J., and A. Perez. 2017. Association of PCFG gray whales on migration. IWC Report SC/A17/GW/02 for the Workshop on the Status of North Pacific Gray Whales. 27-29 April 2017. La Jolla, CA. 10pp.

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