Distribution of sex and age groups of ringed seals Pusa hispida in the fast-ice breeding habitat of Kongsfjorden, Svalbard

• Main Authors: Kovacs, Kit M., Krafft, Bjørn, 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; Jan Mayen; Svalbard; Kongsfjord*; Kongsfjorden; North Atlantic; Pusa hispida; walrus*
• Online Access: http://data.npolar.no/dataset/25641f4d-ce43-5445-a7df-84f05c377895

Spatial distribution of various age- and sex groups of ringed seals (N = 94; 19 adultmales, 33 adult females and 42 subadults) was studied in their fast-ice breeding habitat in Kongsfjorden,Svalbard, during May 2004. Adult females occupied the inner, most stable ice area, whilesubadults were found predominantly in the outer parts of the fast-ice, where the ice conditions aremore unstable. Adult males were scattered across these 2 areas; some were intermingled with breedingfemales while others were found further out towards the ice edge in areas mainly dominated bysubadults. This pattern suggests territorial behaviour with competitive exclusion of the subadults andadult males that cannot compete for territories in the prime breeding areas. The size of adult maleswas correlated with their testosterone levels, but it was not necessarily the largest males that had themost adult female neighbors. The adult males that had the most adult female neighbors were howeversignificantly older than the adult males with fewer female neighbors (18 ± 1 vs. 12 ± 1 yr). Thissuggests that experience (age) likely plays a strong role in achieving reproductive success for maleringed seals. A male:female sex ratio of 1:2.4 was found in the prime breeding area, which suggestsa slightly polygynous mating system.