Study of activity, social interaction and sleep in a captive breeding colony of harbour seals

• Main Author: Almon, Mary Patricia
• Format: Thesis
• Language: English
• Published: Memorial University of Newfoundland 1988
• Subjects: Phoca vitulina
• Online Access: https://research.library.mun.ca/10073/; https://research.library.mun.ca/10073/1/Almon_MaryPatricia.pdf

Because harbour seals (Phoca vitulina) spend more than half their life at sea, researchers have not been able to observe much of their behaviour. The present study of a captive breeding colony of harbour seals explored the relationship between activity, social interaction, and sleep. Activity patterns for all five animals varied over the season ( July 27, 1986 to October 25, 1986) as well as during the day. Adult animals were significantly more active than younger animals. A circadian activity rhythm was found in all seals with most activity occurring during the day. Although the animals in this study were given free access to food, the daily amount they ate varied over the season. As activity increased for both adult males, food consumption decreased. The female and younger animals showed no such activity changes as a function of appetite. -- Copulation was witnessed on three occasions in August. Prior to mating, both adult males engaged in flipperslapping and bubbleblowing. After mating, these behaviours rarely occurred. The use of “space” by both adult males was restricted before mating but this disappeared after mating was over. Sleep varied over the observation period. No sleep was observed in any seal before mating, however, a marked increase occurred after the mating period. No significant differences were found between animals with respect to sleep in the water, however differences did occur between seals sleeping on land. Scanning only occurred on land, never in the water. Individual differences in scanning rates were found among animals.