Body growth in Atlantic walruses (Odobenus rosmarus rosmarus) from Greenland

Authors


Abstract

Morphometric data were collected from 105 Atlantic walruses (Odobenus rosmarus rosmarus) in northwestern Greenland in the periods 1977–78 and 1989–91. Of these 21 walruses were subjected to a detailed study on body composition.

The asymptotic maximum standard body length of Atlantic walruses in NW Greenland was 269 cm for females and 314 cm for males. This is similar to Pacific walruses, but significantly longer than Atlantic walruses from Hudson Bay. Despite this, walruses from NW Greenland apparently do not attain the same total body mass as Pacific walruses (O.r.divergens).

The asymptotic maximum body weights for walruses in NW Greenland were estimated to be 720 kg for females and 1114 kg for males.

Total body surface area was proportional to the two-thirds power of total body weight.

The percentage proportion of blubber and viscera were both negatively correlated to body mass, while skin and muscles constituted a nearly fixed proportion. On average, blubber constituted 19% of total body mass of adult females, 15% of adult males and 24% of subadults of both genders. The average walrus consisted of 18% blubber, 12% skin, 12% viscera and 58% blood, muscle and skeleton. Muscles were estimated to constitute 44% of total body weight.

Allometric functions for weight of internal organs relative to body mass are presented.

Ancillary