Length of skull traits and time of attainment of full size of traits in East Greenland and Svalbard polar bears

Two traits were significantly larger in bears from East Greenland compared to Svalbard bears, and trait size was smaller after 1960 in five traits. For both localities and both age groups (sub adult, adult), mean trait size values were higher in males than females (all: P < 0.05).

Gompertz growth models showed trait size increasing with age in seven traits. Depending on the trait, males reached 95% asymptotic trait size at age 3-10, females at age 2-6. The females of both localities matured at approximately the same age, whereas the Svalbard males generally matured years later than their East Greenland peers.