First report on the stomach contents of long‐finned pilot whales, Globicephala melas, stranded in New Zealand

Abstract

Stomach contents of the long-finned pilot whale, Globicephala melas, are reported for the first time from New Zealand waters. Analyses based on two male and three female whales (2.5-5.3 m in length) that stranded on Farewell Spit, Golden Bay, South Island in December 2005 revealed a diet comprised exclusively of cephalopods (2−33 lower cephalopod beaks per stomach). Two genera of cephalopod from two orders; arrow squid, Nototodarus spp. (Teuthoidea: Ommastrephidae), and common octopus, Pinnoctopus cordiformis (Octopoda: Octopodidae) were represented. A further five pilot whale stomachs were examined and found to be empty.

Stomach contents of long‐finned pilot whales,Globicephala melas, mass‐stranded on Farewell Spit, Golden Bay in 2005 and 2008

“…), and secondarily octopus (Pinnoctopus cordiformis) ( Table 2). These findings are consistent with earlier accounts from this area (Beatson 2007a; Table 2). Based on the known life histories of both Nototodarus spp.…”

“…Based on the known life histories of both Nototodarus spp. and Pinnoctopus cordiformis, Beatson et al (2007a) suggested that long-finned pilot whales stranded in the vicinity of Golden Bay had previously been foraging both near the surface of the water column and on the sea bed, most likely at depths shallower than 150 m. The same would appear true for those whales involved in the 2008 stranding and is relatively consistent with, albeit somewhat shallower than, the foraging behaviour of long-finned pilot whales reported elsewhere. For example, Gannon ( 1995) suggested that long-finned pilot whales off the east coast of the United States foraged at 70-165 m in depth, while Desportes & Mouritsen (1993) suggested that around the Faroe Islands this species feeds at depths between 100 and 500 m. Time-depth recorders deployed on longfinned pilot whales in the Ligurian Sea have recorded foraging dives of between 72 and 648 m (Baird et al 2002).…”

“…additional information on the diet of the long-finned pilot whale, from one site of recurring mass stranding (with more than 20 events recorded from this region since 1978 (NZWSDB)), Golden Bay, is presented here. Earlier reported results and conclusions of Beatson et al 2007a are also re-evaluated in this communication with an investigation of the accuracy of Nototodarus spp. regression equations used to describe the relationships between lower rostral length (LRL) and mantle length (ML) and LRL and biomass of ingested prey.…”

“…Morphometric data and stomach contents were collected from 11 of these whales, following the protocols of Geraci & Lounsbury (1993); three additional whales were unable to be accessed due to the remote location of the carcasses. animals were classified into the age groupings of calf, juvenile, or adult, based on total body length measurements used by Beatson et al (2007a). Gender, body length and maturity classification for each of the animals examined in 2005 and 2008 are provided in Table 1. all stomach chambers were examined for gross pathology in situ.…”

“…Stomach contents recovered from a subset of 124 long-finned pilot whales that stranded on Farewell Spit, Golden Bay in December 2005 provided the first dietary information for this species from New Zealand waters (Beatson et al 2007a;Fig. 1).…”