HAUL‐OUT ACTIVITY OF RINGED SEALS ( PHOCA HISPIDA ) DETERMINED FROM SATELLITE TELEMETRY

• Published in: Marine Mammal Science
• Main Authors: Born, E. W., Teilmann, J., Riget, F.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2002
• Subjects: Aquatic Science; Ecology, Evolution, Behavior and Systematics; Arctic; Greenland; Phoca hispida
• Online Access: http://dx.doi.org/10.1111/j.1748-7692.2002.tb01026.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1748-7692.2002.tb01026.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1748-7692.2002.tb01026.x

A bstract The haul‐out activity of 15 ringed seals ( Phoca hispida ) equipped with satellite‐linked radio transmitters was studied in NW Greenland ( ca. 73°‐78°N). Between 19 June 1997 and 30 June 1999, telemetry data on haulout activity were obtained by the “Land‐Sea‐Reporter” (LSR), “Time‐at‐Depth” (TAD), and “Timelines” (TIM) systems housed within the satellite transmitters. The haul‐out activity (% of total time hauled out) reported by the TIM system, which is specifically designed for collecting haul‐out data, was about 1.4 times higher than that inferred from the LSR, but only about 0.7 of that inferred from TAD data. The TIM were used to describe haul‐out activity. A total of 1,011 d with TIM were obtained (64.5% of a total of 1,568 “seal‐days” monitored) representing data from nearly an entire annual cycle. No differences were found in percentage of time hauled out per month among various age categories. At all seasons the haul‐out time showed considerable individual variation. There were no trends in percentage of time hauled out per month during late summer, fall, and winter (August‐February). During the High Arctic winter darkness (November‐January) the percentage of haul‐out per month ranged between 3.9% in an adult (SD = 2.44, range: 1.1%‐5.7%, n = 3 mo) and 15.7% in a subadult (SD = 1.95, range: 13.7%‐17.6%, n = 3 mo). From late March there was a significant increase in haul‐out time. Between 1 and 30 June, when aerial surveys of basking ringed seals usually are conducted, the haul‐out time (% per day) increased from about 25% to about 57%. No tendencies in diel haul‐out activity were revealed.