Southern right whales wintering in the Auckland Islands

Historically, southern right whales were widely distributed in New Zealand waters. This population, was driven to commercial extinction following extensive exploitation during the early 19th century (Dawbin 1986). It was further depleted by illegal Soviet hunting in 1950-1970 (Tormosov et al. 1998). While right whale sightings around mainland New Zealand remain rare, up to 165 whales can be found at the Auckland Is in a single day during winter. Despite what appears to be adequate habitat along the eastern coastline, the whales' distribution is largely limited to Port Ross, Laurie Harbour and waters around Enderby I. The relatively small area where so many whales congregate means that at peak season the density of whales at the Auckland Is is very high (approximately 8 whales/km 2). The residency period extends from at least early May to at least the end of September, with peak numbers in July and August. Cow/calf pairs utilise most areas within Port Ross and Laurie Harbour, and show a preference for shallow waters. The photographic catalogue contains 410 animals (including 76 cows) and capture-recapture analysis suggests that the size of the population is likely to be between 740 and 1140 animals. The low level of gene flow between this population and the southwestern Australia population and other wintering grounds underlines the uniqueness of the Auckland Is population. The Auckland Is are currently the primary calving and breeding ground for southern right whales in New Zealand waters. Long-term monitoring programmes should be directed at the continued annual collection of photographs for individual identification, investigating the location of the feeding grounds and developing a sighting and photo-identification network for southern right whales around mainland New Zealand.