Rubbing behaviour of belugas, Delphinapterus leucas, in a high Arctic estuary

• Published in: Canadian Journal of Zoology
• Main Authors: Smith, Thomas G., St. Aubin, David J., Hammill, Michael O.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1992
• Subjects: Beluga*; Delphinapterus leucas
• Online Access: http://dx.doi.org/10.1139/z92-322; http://www.nrcresearchpress.com/doi/pdf/10.1139/z92-322

From about mid-July to mid-August belugas (Delphinapterus leucas) over five seasons spent from 27 to 38 days at Cunningham Inlet (74°05′N, 93°45′W), where maximum numbers in each of eight seasons varied from 762 to 1741. While in the estuary, whales actively rub all their skin surface on the mud, pebble, and sharp limestone substrate near shore. Rubbing behaviour is more frequent early in the period of estuarine occupation and is exhibited by all age-classes with the exception of neonates and their dams. Remains of skin found in the area are proof that the epidermal surface is cut and shed from the whales in the shallow areas of the inlet. Active abrasion of skin surfaces softened by exposure to warm fresh water is thought to accelerate the moult, which is linked to a seasonal endocrine cycle and synchronized to meet the energetic demands imposed by their environment.