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Browse the 1966 Encyclopaedia of New Zealand
Graphic: An Encyclopaedia of New Zealand 1966.


This information was published in 1966 in An Encyclopaedia of New Zealand, edited by A. H. McLintock. It has not been corrected and will not be updated.

Up-to-date information can be found elsewhere in Te Ara.



Breeding Habits of New Zealand Seals

The breeding habits of the three New Zealand species of seals are very similar. Early in the breeding season, about October or November, the large bulls haul out of the water and take up territories along beaches and rocky shores. Each defends its area against incursion by neighbours and fights off younger bulls which attempt to carve out territories of their own. Three to five weeks later the cows begin to arrive, forming groups or harems of 10 to 15 within the territories. The old bulls defend their harems against the attentions of the younger bulls, rounding up the straying cows and fighting intruders almost continuously throughout the summer, with considerable expenditure of energy. They live only on their reserves of fat during the breeding season which may extend over three months or more.

The cows give birth to their pups shortly after leaving the water, and usually mate within a few days or weeks of parturition. The fertilised egg of the elephant seal (probably also of the other species) remains unattached in the uterus for several weeks before implanting, so that development begins late in summer, and the foetus, with a true gestation period of nine to 10 months, is ready for birth 11 to 12 months after fertilisation. The pup of the elephant seal weighs about 100 lb at birth and measures slightly over 4 ft from nose to tail. Its birth weight doubles in 11 days (the human infant doubles its birth weight in six months), and the mother ceases to feed the pup after three to four weeks. Its downy birth coat is shed rapidly during the first week of life (or may even be lost before it is born), and the pup is ready for the sea at an age of six to eight weeks. Fur seals and sea lions keep their young by them for several months; the pups apparently grow more slowly and take longer to reach independence.

Other species of seals visit New Zealand from time to time; most frequently reported are young sea leopards (Hydrurga leptonyx) and Weddell seals (Leptonychotes weddelli) from the Antarctic. Sea leopards are also seen often about the sub-Antarctic islands.

Next Part: Sealing