Although the Ziphiidae are the second-most speciose family of cetaceans, information on beaked whale species and populations has been limited by the difficulties in finding and approaching free-ranging individuals. Site fidelity, patterns of association, and movements of two species, Cuvier’s (Ziphius cavirostris) and Blainville’s (Mesoplodon densirostris) beaked whales, were assessed using a 21-yr photographic data set from the west coast of the island of Hawai‘i. Resightings of individuals of both species spanned 15 yr, suggesting long-term site fidelity to the area. Long-term resightings were documented primarily from adult females of both species. Group sizes for both species were small and most groups had only a single adult male present. For Blainville’s beaked whales, repeated associations between adult females and adult males were documented for all resightings of adult males over periods from 1 to 154 d. Among adult females, although repeated associations occurred up to 9 yr apart, individuals were seen separately in intervening years. Individuals of both species seen on multiple occasions were typically documented in multiple months/seasons, suggesting they may use the study area throughout the year. Such long-term site fidelity has implications both for potential population structure and for susceptibility of beaked whale populations to anthropogenic impacts.
Citation:
McSweeney, D.J., R.W. Baird, and S.D. Mahaffy. 2007. Site Fidelity, Associations and Movements of Cuvier’s (Ziphius cavirostris) and Blainville’s (Mesoplodon densirostris) Beaked Whales off the Island of Hawai’i. Marine Mammal Science 23(3): 666-687. doi: 10.1111/j.1748-7692.2007.00135.x
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