Two non‐mutually exclusive hypotheses on the function of the humpback whale song are: (1) it attracts females to the male singer; (2) it is a male‐male display, that may order status. To evaluate these, from 24 January‐13 April 1997 off Maui, Hawaii, 42 singers were located, audio‐recorded, photo‐identified and monitored for interactions with other whales. Whales that joined singers were biopsy sampled for molecular determination of sex. In 76% (32 of 42) of the interactions, a lone non‐singing adult joined the singer. In the remainder, singers stopped singing and joined a nearby group or accompanied other whales. In 81% (26 of 32) instances where a lone adult joined a singer, the pair split again within minutes; otherwise a group formed. In one such group the pair became a trio and eventually joined a competitive group. Behavior in joining/splitting interactions ranged from a single pass‐by, to surface activity such as tail lobs and breaches. The sex of 22 joiners was determined: 14 genetically and eight behaviorally. All were males. Humpback whale song preceded, and at times followed, male‐male interactions of variable duration and agonistic level in and around the breeding season. If considered within the context of a proposed dominance polygyny mating system, these observations appear to support speculation that the song may function in male social ordering.

Migratory destinations of northeast Pacific humpback whales (Megaptera novaeangliae) were determined by repeat sightings of photographically identified individuals, using the black and white pigment patterns on the ventral side of the flukes. Individuals identified between 1975 and 1982 included 1056 in Hawaii, 420 in southeast Alaska, 54 in Prince William Sound, Alaska, 8 in British Columbia, and 12 in the Revillagigedo Islands, Mexico. Of these, 51 were found in Hawaii and southeast Alaska, 8 in Hawaii and Prince William Sound, 1 in Hawaii and British Columbia, and 1 in Mexico and Hawaii. Some travelled for four, five, and six successive seasons between Hawaii and southeast Alaska. One whale was found in British Columbia one summer and in southeast Alaska the next; the same individuals were commonly found off both Kona, Hawaii, and West Maui in winter. The study suggests that separate summer feeding areas may exist in the northeast Pacific where individuals prefer to feed. Migratory connections suggest that all humpbacks in the eastern North Pacific are of the same stock.

Habitat utilization and prey species of Vancouver Island gray whales were investigated by (1) summarizing 26 yr of distribution and feeding data and (2) conducting intensive observations in Clayoquot Sound, Vancouver Island, from 1989 to 1996. Whale distribution and movements were monitored from March to November through systematic boat surveys and whale‐watch sighting programs. Prey species were collected by suction hose and plankton net or determined through analysis of fecal samples. Gray whales utilized virtually all of the southern west coast of Vancouver Island over the 26‐yr observation period. Distribution, prey species, and feeding behavior showed marked variability during any one season and between years. Some feeding areas were used on an annual basis, others with >10‐yr intervals between use. Feeding occurred in shallow sand or mud bays, eel grass beds, kelp beds, in the open water column, and at the surface. Young whales appeared to utilize habitat and prey species differently than adults. Main prey species included herring eggs/larvae (Clupea harengus pallasi), crab larvae (Cancer magister megalops, Pachycbeles spp. zoea), mysids (Holmesimysis sculpta, Neomysis rayii, Acanthomysis spp.), amphipods (Ampelisca spp., Atylus borealis), and ghost shrimp (Callianassa californiensis). The definition and relative importance of specific feeding grounds and the study of human impacts on this population are complicated by its broad and variable use of habitat and prey species.

Humpback whales feed in several high‐latitude areas of the North Pacific. We examined the interchange of humpback whales between one of these areas, off California, and those in other feeding grounds in the eastern North Pacific:. Fluke photographs of 597 humpback whales identified off California between 1986 and 1992 were compared with those off Oregon and Washington (29); British Columbia (81); southeastern Alaska (343); Prince William Sound, Alaska (141); Kodiak Island, Alaska (104); Shumagin Islands, Alaska (22); and in the Bering Sea (7). A high degree of interchange, both inter‐and intrayear, was found among humpback whales seen off California, Oregon, and Washington., A low rate of interchange was found between British Columbia and California.: two whales seen near the British Columbia/Washington border were photographed off California in a different year, No interchange was found between California and the three feeding areas in Alaska. Humpback whales off California, Oregon, and Washington form a single intermixing feeding aggregation with only limited interchange with areas farther north. These findings are consistent with photographic identification studies in the North Atlantic and with genetic studies in both the North Atlantic and North Pacific.

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