Heide-Jørgensen, M.P., Bloch, D., Stefansson, E., Mikkelsen, B., Ofstad, L.H. & Dietz, R. 2002: Diving behaviour of long-finned pilot whales Globicephala melas around the Faroe Islands. - Wildl. Biol. 8: 307-313.
Three long-finned pilot whales Globicephala melas were equipped with satellite-linked time-depth recorders on the Faroe Islands on 15 July 2000. The purpose was to study the diving behaviour and habitat use of free-ranging pilot whales in the northeast Atlantic. Summarised data on the diving behaviour of the whales were collected for up to 129 6-hour periods. The maximum depth of dives was 828 m and the mean number of dives below 12 m was 12.2/hour (SD = 8.2). On average, the whales spent 60% of their time above 7 m depth. All three whales had significantly longer surface times when they were outside the continental shelf than when they were on the shelf. The mean vertical speeds ranged from 0.9 m/second for dives to 150 m to 2.3 m/second for dives to 600 m. No dives below 12 m lasted longer than 18 minutes, and more than 60% of dives lasted less than three minutes. The mean number of dives that lasted less than one minute was significantly higher in offshore areas than on the continental slope for all three whales. Compared to other odontocetes of similar size, long-finned pilot whales apparently either have a lower dive capacity or utilise a niche in the water column that requires less diving activity.
Key words: diving behaviour, Faroe Islands, Globicephala melas, pilot whale, satellite tracking
Mads Peter Heide-Jørgensen, Greenland Institute of Natural Resources, c/o National Marine Mammal Laboratory, 7600 Sand Point Way NE, Seattle, WA 98115, USA - e-mail: firstname.lastname@example.org
Dorete Bloch, Eydfinn Stefansson & Bjarni Mikkelsen, Museum of Natural History, FO-100 Tórshavn, Faroe Islands - e-mail addresses: email@example.com (Dorete Bloch); firstname.lastname@example.org (Eydfinn Stefansson); email@example.com (Bjarni Mikkelsen)
Lise Helen Ofstad, Fisheries Laboratory, FO-100 Tórshavn, Faroe Islands - e-mail: firstname.lastname@example.org
Rune Dietz, National Environmental Research Institute, Department of Arctic Environment, Frederiksborgvej 399, Postbox 358, DK- 4000 Roskilde, Denmark - e-mail: email@example.com
Corresponding author: Mads Peter Heide-Jørgensen
Received 7 August 2001, accepted 17 April 2002
Associate Editor: Jan Lindström