Antarctic orca in New Zealand waters?

Abstract

I report on a group of orca (Orcinus orca (Linnaeus, 1758)) near the Bay of Islands, New Zealand, which were a lighter coloration than orca usually seen in these waters. Differences in pigmentation included a light grey caudal peduncle area and a dorsal cape, which has previously only been described for Antarctic orca. The size and shape of the eye patches were not consistent with orca photo-identified in New Zealand. I suggest that this group of orca, although observed in New Zealand waters, were of Antarctic origin.

Cookie Cutter Shark (Isistius sp.) Bites on Cetaceans, with Particular Reference to Killer Whales (Orca) (Orcinus orca)

“…Cookie cutter shark bites have been previously reported on orca (Pitman et al, 2001;Baird et al, 2006;Burdin et al, 2006Burdin et al, , 2007Visser et al, 2007;Renner & Bell, 2008), including in New Zealand waters, where the first records of cookie cutters shark bites on orca worldwide were documented (Visser, 1999(Visser, , 2007Visser et al, 2010). We provide further records of orca from various geographic regions with cookie cutter shark bite marks.…”

“…comm., 15 July 2010). Orca ecotypes are italicised and defined as follows: the Austral ecotype is found in southern waters and exhibits a notably smaller eye patch than "typical" orca (Fair, 2010;Visser, 2010a;Young & Egan, 2011); Coastal ecotype refers to the population of orca regularly observed in the inshore waters of New Zealand (e.g., see Visser, 2000); Pelagic ecotype refers to those orca typically found offshore from northern New Zealand but occasionally in coastal waters (e.g., see Visser et al, 2010); Type A, Type B, and Type C ecotypes are typically found in Antarctic waters, but Type B and Type C are known from other waters (Visser, 1999;Pitman & Ensor, 2003;this publication).…”

“…As far as we can ascertain, the first worldwide, peerreviewed publication discussing cookie cutter shark bite marks on orca was by Visser (1999). Although photographed in the Bay of Islands, New Zealand (Record #3.2; location of all New Zealand records is shown in Figure 3), these orca were suspected of originating from Antarctic waters and were subsequently identified as Antarctic Type B ecotype (Visser, unpub.…”

Using platforms of opportunity to determine the occurrence and group characteristics of orca (Orcinus orca) in the Hauraki Gulf, New Zealand

“…Although this is a reflection of high effort in this region, it is also possible that this area is used more frequently by orca, or that a larger subpopulation exists in this region (Visser 2000). Indeed, whilst New Zealand orca have been found to range over large distances (Visser 1999a(Visser , 2000(Visser , 2007, it has also been suggested that some individuals exhibit a smaller home range (Visser 2000(Visser , 2007. Another possible reason for the prevalence of orca records within the HG relates to platform bias, as the PoP may actively search for this species.…”

“…Despite the difficulties of conducting research on highly mobile predators, orca have been studied in New Zealand waters during the past two decades (see Visser 1999aVisser ,b,c, 2000Visser , 2005Visser & Fertl 2000;Visser et al 2010;Dwyer & Visser 2011). Whilst the local population is small (fewer than 200 individuals; Visser 2000), three possible subpopulations have been described (i.e.…”