Movements and diving of bearded seal (Erignathus barbatus) mothers and pups during lactation and post-weaning

• Main Authors: Kovacs, Kit M., Gjertz, Ian, Wiig, Øystein, Lydersen, Christian
• Format: Dataset
• Language: unknown
• Published: Norwegian Polar Institute 2008
• Subjects: BIOTA; biology; EARTH SCIENCE; BIOLOGICAL CLASSIFICATION; ANIMALS/VERTEBRATES; MAMMALS; CARNIVORES; SEALS/SEA LIONS/WALRUSES; BIOSPHERE; ECOLOGICAL DYNAMICS; Arctic; Svalbard; Greenland; Norway; Jan Mayen; bearded seal; Erignathus barbatus; Kongsfjord*; Kongsfjorden; North Atlantic; walrus*
• Online Access: http://data.npolar.no/dataset/dbbb9da3-b31f-555b-8c60-9102e3d64963

The study had three objectives: 1) to determine the movement patterns of bearded seals in the coastal areas of Svalbard, 2) to determine the length of the nursing period and the age at weaning, and 3) to obtain ecological knowledge about diving skills and diving behaviour of a little-known arctic seal species. Eleven bearded seals (Erignathus barbatus) were tagged with satellite-linked dive recorders (SLDRs) in Kongsfjorden, Svalbard, Norway, in May 1994. These animals included four mother-pup pairs and three single pups. The SLDRs collected dive-depth data from 0 to 250+ m in 14 intervals (bins) with a precision of 2 m. The maximum depth that can be recorded is 490 m and the minimum depth to be recorded as a dive was set at 2 m. Dive-duration data were also collected in 14 bins.The seals were tracked for 21±258 days. A total of 207,000 dives were recorded. Bearded seal mothers showed limited movements during the nursing and moulting periods. After weaning, the pups moved out of the tagging area and dispersed coastally. One pup left Svalbard and moved far offshore to Greenland and Jan Mayen. Bearded seal adults displayed a bi-modal dive behaviour, with peaks of activity that were shallower than 10 m or from 50 to 70 m. Most dives for adult seals (97%) were shorter than 10 min. Young pups performed dives that were shallower and shorter in duration than their accompanying mothers, but diving skills improved rapidly with age. Six of the seven pups dived deeper than 448 m by the time they were 2 months old. Analyses of movement data with respect to separation of mother-pup pairs suggest a lactation period of about 24 days.