S. Childerhouse et N. Gales, HISTORICAL AND MODERN DISTRIBUTION AND ABUNDANCE OF THE NEW-ZEALAND SEA LION PHOCARCTOS-HOOKERI, New Zealand journal of zoology, 25(1), 1998, pp. 1-16
This paper describes both the modern and the pristine distribution, br
eeding range, and relative abundance of the New Zealand sea lion (Phoc
arctos hookeri). Archaeological data and historical references were us
ed to determine the pristine status of the sea lion, and its present s
tatus was determined from recent scientific studies and observations.
The sea lion had a substantially more widespread distribution before t
he arrival of humans in New Zealand than it does today. The species us
ed to range along the whole length of the coast, from the north of the
North Island through to Stewart Island and the subantarctic islands.
Although we have no direct estimate of pristine abundance, the present
population size is clearly reduced. Subsistence and commercial killin
g of sea lions is the most likely cause of historical changes in distr
ibution and abundance. Their pristine breeding range extended at least
as far north as Nelson and may have extended to the North Island. The
present breeding range is restricted to the Auckland Islands and Camp
bell Island. Within the last 10 years a few individuals have started t
o breed on mainland New Zealand and Stewart Island, which may reflect
a slow recolonisation of earlier breeding grounds. Pup production at S
andy Bay, Enderby Island, has been stable for at least the last three
decades, and no major changes in pup production at Dundas Island and F
igure of Eight Island are apparent.