New insights into the northward migration route of gray whales between Vancouver Island, British Columbia, and southeastern Alaska

Abstract

The route taken by northward migrating gray whales during spring between Vancouver Island and southeastern Alaska, a distance of about 575 km, has long been uncertain. It is generally believed that the whales closely follow the western, outer coastline of Haida Gwaii (formerly the Queen Charlotte Islands), an archipelago lying between Vancouver Island and southeastern Alaska, consistent with their pattern of migrating close to shore over the majority of their northward migratory corridor. By tracking satellite‐tagged individuals and surveying whales from shore bases, we provide evidence that this is not the primary migratory corridor, but instead that most whales migrate through Hecate Strait and Dixon Entrance, broad waterways that lie to the east and north of Haida Gwaii. By using this route, northbound gray whales potentially face a wider range of industrial activities and developments than they would by migrating along the outer coast.

Whale killers: Prevalence and ecological implications of killer whale predation on humpback whale calves off Western Australia

“…), assuming the estimated error radii represented the standard deviations of normally distributed errors about each location ( e.g ., Ford et al . ). In addition to tracking killer whale movements over time, we also used the tag transmissions to relocate animals and extend our focal‐follow capability ( e.g., Pitman and Durban ).…”

“…The tag was programmed to transmit up to 700 times during 18 h each day, and locations with error radii were estimated by the Argos satellite system (Lopez and Malard e 2011). To make inference about the movement track and speeds, we fit a continuous time-correlated random walk model (Johnson et al 2008), assuming the estimated error radii represented the standard deviations of normally distributed errors about each location (e.g., Ford et al 2013). In addition to tracking killer whale movements over time, we also used the tag transmissions to relocate animals and extend our focal-follow capability (e.g., Pitman and Durban 2012).…”

Use of time‐at‐temperature data to describe dive behavior in five species of sympatric deep‐diving toothed whales

“…) assuming the estimated error radii represented the standard deviations of normally distributed errors about each location ( e.g ., Ford et al . ). Following initial model fitting, the measurement error shock diagnostic of de Jong and Penzer () was used to eliminate significant outliers ( P ≤ 0.01), and the model was refitted to estimate a movement track for each whale.…”

Development and assessment of a new dermal attachment for short‐term tagging studies of baleen whales

“…More recently, small surface‐mounted satellite tags have been used with success on odontocetes (Andrews, Pitman & Balance ) and some baleen whales (Ford et al . ). This design is characterized by a tag housing that is not implanted, but instead is externally mounted on the animal via short barbed darts that anchor in the dermis.…”