habitat_narrative
Marine
Gaskin (1968) suggested that this species typically prefers cooler temperate waters between the Subtropical and Antarctic Convergences, at water temperatures of 9â 6°C, thus the lack of sightings in the warmer regions off the southern Indian Ocean is not unexpected (Rose & Payne 1991). However, all of Cruickshank and Brownâs (1981) sightings were recorded in waters more than 15.7°C, though subsurface temperatures are likely to have been substantially lower. Thus, it is expected that although this species may be more common in cooler waters (9â16°C), they are certainly not restricted to this temperature range (Rose & Payne 1991). Although generally preferring deep waters, this species does occur in nearshore regions with steep coastal gradients.Although the feeding ecology of the Southern Right Whale Dolphin is poorly documented, they are believed to feed nocturnally (Torres & Aguayo 1979), predominantly on squid and fish (Jefferson et al. 1994). Laternfish (mostly Hygophum hanseni) and squid (primarily Gonatus antarcticus) remains were found in the stomach of an individual captured of Chile (Torres & Aguayo 1979). Additionally, the stomach of two individuals stranded in New Zealand contained the fish species Macruronus novaezelandiae and the squid Nototodarus sloanii (Baker 1981). Rose and Payne (1991) conclude that Southern Right Whale Dolphins are highly gregarious and specialised feeders that, due to their high levels of activity, may be reliant on strong upwelling regions of high productivity in order to meet their energetic demands.
This species has been documented in schools ranging from 4 to 1,000 individuals (Gaskin 1968). Groups of L. peronii have been observed traveling at rapid speeds (estimated at about 20 knots, Rose & Payne 1991) usually just below the surface, surfacing only briefly (Cruickshank & Brown 1981). Southern Right Whale Dolphins occasionally associate with other cetacean species, such as Dusky Dolphins (Lagenorhynchus obscurus) and pilot whales (presumably Long-finned Pilot Whales, Globicephala melas, due to their west coast distribution) (Cruickshank & Brown 1981). Very little information is known about the reproductive ecology of these species, though they have been recorded as sexually mature at length of 2.18 m and 2.51 m for females and males, respectively (Van Waerebeek et al. 1991).
Ecosystem and cultural services: Marine mammals integrate and reflect ecological variation across large spatial and long temporal scales, and therefore they are prime sentinels of marine ecosystem change; polar cetaceans are useful for assessing the effects of rapid changes in sea ice conditions on food webs in these strongly seasonal ecosystems (Moore 2008).
