Unpublished doctoral dissertation.
University of Hawaii.
Habitat utilization, migratory timing, and male escorting strategies
of humpback whales in the Hawaiian Islands.
- Craig, A.S.
- Department of Zoology and Psychology , University of Hawaii,
Kewalo Basin Marine Mammal Lboratory, 1129 Ala Moana Blvd., Honolulu,
HI, USA, 96814
-
- (C) 2001 University of Hawaii
Photographs of humpback whales identified in the Hawaiian Islands
from 1976 through 1995 and shore-based observations conducted
from 1995 through 1998 were used to investigate (a) migratory
timing and residency, (b) reproductive rates and habitat preferences
of females, (c) regional and temporal trends in density and pod
characteristics, and (d) male escorting strategies and female
attractiveness. Results suggested that juveniles and females with
no calf arrive at and depart from the Hawaiian Islands earlier
than females with calf and males, and that the migratory timing
of individual females varies with reproductive state. There were
no significant differences in within-season resighting rates or
resighting intervals among different classes of whale. The interval
between first and last identification was less then two weeks
in most cases. Calves formed a significantly larger proportion
of the population of Maui than off the Big Island, and Maui waters
also contained a higher ratio of calves to females. Females with
no calf had higher reproductive potential for the following year
than females with calf. Individual females appeared to prefer
Maui when with calf and the Big Island when without. Whale density
and mean pod size were significantly greater of Maui, with significantly
fewer singletons and more pods containing four or more adults
than were off the Big Island. The seasonal peak in abundance occurred
earlier at the Big Island than Maui. Females with no calf were
significantly less likely to be alone and more likely to be in
large pods than females with calf. Individual females attracted
more males when without a calf than with calf. Head lunges were
observed more frequently in non-calf pods then calf pods. The
mean number of escorts accompanying females with calf increased
as the season progressed. Overall, the results showed that there
are regional and temporal variations in the demographic profile
of humpback whales wintering in the Hawaiian Islands. Also, the
migratory timing, habitat preferences, and attractiveness of individual
females vary with reproductive state. Finally, males are more
likely to compete for females with no calf than for females with
calf, but become less choosy as the season progresses.
Craig, A. S. (2001). Habitat utilization, migratory timing, and
male escorting strategies of humpback whales in the Hawaiian Islands.
Unpublished doctoral dissertation. University of Hawaii
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