Seasonal home ranges and fidelity to breeding sites among ringed seals

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.

Adolescents’ Occupational and Educational Aspirations and Expectations: Links to High School Activities and Adult Educational Attainment

This longitudinal study explored adolescents’ future-oriented cognitions, current activities, and later educational attainment using data from 317 adolescents (55% female; mean age = 14.98 years, SD = 0.85) followed into early adulthood. Aspirations and expectations regarding work and education showed modest stability from year to year. Exploration of the reciprocal relations between these cognitions and adolescents’ activities supported both unidirectional and bidirectional effects, with different patterns emerging for aspirations and expectations. In multiple regression analyses, future-oriented cognitions predicted adult educational attainment; follow- up analyses indicated that the effect of adolescents’ expectations was partially mediated by participation in extracurricular activities. These results suggest a potentially important influence of adolescents’ future-oriented cognitions on their current behavior and future attainments.