Activity budget and diving behavior of gray whales (Eschrichtius robustus) in feeding grounds off coastal British Columbia |
| |
Authors: | Lei Lani Stelle William M Megill † Michelle R Kinzel ‡ |
| |
Institution: | Department of Biology, University of Redlands, Redlands, CA 92373, U.S.A. and Coastal Ecosystems Research Foundation, The White House, Dawson's Landing, British Columbia, V0N 1M0, Canada E-mail:; Coastal Ecosystems Research Foundation, The White House, Dawson's Landing, British Columbia, V0N 1M0, Canada and Centre for Biomimetic and Natural Technologies, Mechanical Engineering Department, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom; Coastal Ecosystems Research Foundation, The White House, Dawson's Landing, British Columbia, V0N 1M0, Canada |
| |
Abstract: | Behavior and diving patterns of summer resident gray whales ( Eschrichtius robustus ) foraging on mysids were studied in coastal bays along the north shore of Queen Charlotte Strait, British Columbia. In this region, gray whales were found to feed primarily on planktonic prey rather than on the benthos as in their primary feeding areas further north. During the summers of 1999 and 2000, whales spent most of their time actively feeding or searching for prey (77%), whereas only 15% of their time was spent traveling and 8% socializing. The majority of the dives were short; the mean dive duration was 2.24 min with approximately three respirations per surfacing and 15 s between blows. Whales dove frequently (26.7 h?1), spending only 17% of their time at the surface with an overall blow rate of 1.14 respirations per minute. Activity states were characterized by significantly different diving and respiratory parameters; feeding whales dove more frequently, with shorter intervals between respirations, thus spending less time at the surface compared to when traveling or searching. This diving pattern differs from benthic-feeding whales and likely optimizes capture of the mobile mysid swarms in shallow waters. |
| |
Keywords: | gray whale Eschrichtius robustus diving activity budget foraging behavioral ecology mysticete mysids |
|
|