Seasonal home ranges and fidelity to breeding sites among ringed seals

Authors

Brendan P. Kelly, University of Alaska SoutheastFollow
Oriana H. Badajos, University of Alaska Southeast
Mervi Kunnasranta, University of Alaska Southeast
John R. Moran, University of Alaska Southeast
Micaela Martinez-Bakker, University of Alaska Southeast
Peter Boveng, National Marine Mammal Laboratory, Alaska Fisheries Science Center, National Marine Fisheries Service, NOAA
Douglas Wartzok, Florida International University, University Park PC 526, Miami, FL

Date of this Version

2010

Comments

Published in Polar Biol.

Abstract

Population structure and patterns of habitat use among ringed seals (Phoca hispida) are poorly known, in part because seasonal movements have not been adequately documented. We monitored the movements of 98 ringed seals in the Beaufort and Chukchi seas between 1990 and 2006 using three forms of telemetry. In the winter—spring period (when the seals were occupying shorefast ice), we used radio and ultra-sonic tags to track movements above and below the ice, respectively. We used satellite-linked transmitters in summer and fall (when the seals ranged away from their winter sites) to track at-sea movements. In the shorefast ice habitat, the home ranges of 27 adult males ranged from\1 to 13.9 km² (median = 0.628) while the home ranges of 28 adult females ranged from \1 to 27.9 km² (median = 0.652). The 3-dimensional volumes used by 9 seals tracked acoustically under the ice averaged 0.07 (SD = 0.04) km³ for subadults and adult males and 0.13 (SD = 0.04) km³ for adult females. Three of the radio-tracked seals and 9 tracked by satellite ranged up to 1,800 km from their winter/spring home ranges in summer but returned to the same small (1–2 km²) sites during the ice-bound months in the following year. The restricted movements of ringed seals during the ice-bound season— including the breeding season—limits their foraging activities for most of the year and may minimize gene flow within the species.