Migratory destinations of humpback whales that feed off California, Oregon and Washington

Abstract

ABSTRACT. The migratory destinations of humpback whales that feed off California. Oregon and Washington were determined using photo-identification. Fluke photographs of 594 individuals were taken between 1981 and 1992 and compared to collections from 9 wintering regions in the North Pacific: Ogasawara (162) and Okinawa (17) islands of Japan; the Big Island and Maui (634 for both) and Kauai (384) of Hawaii; the Revillagigedo Archipelago (450), the mainland coast (383) and Baja Peninsula (471) of Mexico; and Central America (31). A total of 160 matches were found to 6 central and eastern North Paclfic wintering regions, with most from Central America, Baja, and mainland Mexico. Of whales identified off Central America, 84 % were resighted off California-Washington, this high rate of interchange suggests that whales in these tropical waters appear to be comprised entirely of animals from the California-Washington feeding aggregation. Humpback whales seen off Central America were reslghted disproportionately off southern California while those from mainland ~Vexico tended to be seen off northern California-Washington. From 157 same-season migratory transits documented, the shortest were 29 d to Baja and 56 d to Costa Rica and the longest distance was 5322 km. Of the California-Washington whales with known sex, the proportion of males identified at a wintering region was significantly higher than females (2.2:1, p < 0.05).

Geographic variation of persistent organic pollutant levels in humpback whale (Megaptera novaeangliae) feeding areas of the North Pacific and North Atlantic

“…The significant differences in contaminant levels between the southern and northern California regions provide evidence that animals may show site fidelity to specific feeding locations, even within the relatively distinct California-Oregon-Washington region. This is consistent with previous research describing overlapping migratory corridors of whales off the California coast [18]. Whales that overwinter in Central America were typically resighted in southern California feeding grounds, whereas those overwintering in mainland Mexico and Baja California were seen feeding primarily in northern California.…”

“…Because of the large geographic extent from which California samples were obtained, two regions within California were considered: southern California, including samples collected south of Point Sur (36820 0 N; n ¼ 5), and northern California, including individuals sampled north of Point Sur (n ¼ 5). The same boundary has been used previously to define subregions for humpback whales that feed off the California coast [18].…”

Habitat-Based Density Models for Three Cetacean Species off Southern California Illustrate Pronounced Seasonal Differences

“…The majority of humpback whales that feed off California from spring to fall migrate to breed in waters off mainland Mexico and Central America during the winter months (Calambokidis et al, 2000;Barlow et al, 2011b). However, humpback whales have been sighted year-round off California (Dohl et al, 1978(Dohl et al, , 1983Forney and Barlow, 1998;Campbell et al, 2015).…”

Two Years of Oceanographic and Meteorological Data from the UNAM Buoy Anchored at Socorro Island in the Mexican Pacific

“…Adapted from [25] [26] [37]- [39]. important feeding, breeding, and transit area for cetaceans of the Mexican Pacific, in particular humpback whales [18] [19]. Sixteen species of whales and dolphins have been reported in the area [20].…”