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

Abstract

New data are reported on the diet of the long-finned pilot whale, Globicephala melas, based on stomach contents recovered from whales involved in a mass stranding on Farewell Spit, Golden Bay, South Island, on 23 January 2008. The stomachs of 11 whales were examined, from which identifiable prey remains were recovered from six, four females and two males (3.1-5.4 m in length). Prey remains comprised exclusively cephalopod beaks (1-46 beaks per whale), attributed to two genera in two orders: arrow squid, Nototodarus spp. (Teuthoidea: Ommastrephidae), and common octopus, Pinnoctopus cordiformis (Octopoda: Octopodidae). The stomachs of eight whales were infested with parasitic nematodes, with two ulcerated; the stomachs of five whales did not contain any prey remains. These data complement and are comparable to the only other information available for this species from this region, reported from whales mass-stranded at this same location in December 2005. Lower beak rostral length versus mantle length and biomass regression equations for Nototodarus spp. are reviewed, highlighting the importance of the use of species-specific regression equations for reconstructing both cephalopod mantle length and biomass from lower beak remains in dietary studies.

Patterns and trends in the diet of long‐finned pilot whales (Globicephala melas) in the northeast Atlantic

“…In Brazil, the stomachs of fives whales stranded from 1985 to 1998 contained remains of squid of the oceanic families Lycoteuthidae, Histioteuthidae, and Cranchiidae (Santos and Haimovici 2001). Cephalopods were also found as the main prey category in pilot whales stranded in France (Pierrepont et al 2005), New Zealand (Beatson et al 2007, Beatson andO'Shea 2009), and the Bay of Biscay (Spitz et al 2011).…”

Ecological tracers and at-sea observations document the foraging ecology of southern long-finned pilot whales (Globicephala melas edwardii) in Kerguelen waters

“…By contrast, the biology, including the food and feeding habits of the southern subspecies, is poorly documented. Dietary investigations on the southern long-finned pilot whale focused primarily on stomach content analysis of a few stranded individuals from Tasmania (Gales et al 1992), New Zealand (Beatson et al 2007a, b;Beatson and O'Shea 2009), Tierra del Fuego (Goodall and Galeazzi 1985;Clarke and Goodall 1994;Mansilla et al 2012) and Brazil (dos Santos and Haimovici 2001), with no available information from the southern Indian Ocean. Cephalopods form the bulk of the food, but stomach content examination of stranded individuals suffers several drawbacks including overestimation of prey with hardly digestible elements that accumulate over time (e.g.…”

Stomach contents of long-finned pilot whales, Globicephala melas mass-stranded in Tasmania

“…Although LFPWs strand in Tasmania throughout the year (except May and June), there is a distinct stranding peak during summer, from September to December (DPIPWE unpublished data). This apparent seasonality is also observed in LFPWs that strand along the New Zealand coastline [2, 3, 19, 20], and be as a result of long-distance migrations of LFPWs past Tasmania during summer, or reflective of seasonal changes in prey distribution from offshore areas onto the continental shelf and near-shore waters.…”

“…Diet studies have analysed the stomach contents obtained from LFPWs in many parts of the world [3, 4, 29–31], where in general, cephalopods are a main component of LFPW diet, although fish may also be important in some areas [32–34]. Previous reports of LFPW food habits have yielded three dietary patterns: (1) diverse diet (≥10 prey species) dominated by cephalopods [4, 29, 30]; (2) restricted diet (≤3 species) dominated by cephalopods [35, 36]; and (3) restricted diet (≤3 species) dominated by fish [34, 37, 38].…”

“…Similar investigations into the diet of 14 LFPWs stranded in two events along the New Zealand coastline found a restricted diet (≤3 species) dominated by Nototodarus spp. and Octopus maorum [3, 20, 39]. The diet of Southern Hemisphere LFPWs has also been investigated in Chile [40], Argentina [41], southern Brazil [42], South Africa [43] and Antarctic/Sub-Antarctic [44].…”