Feeding ecology of Cuvier's beaked whale (Ziphius cavirostris): a review with new information on the diet of this species

Abstract

Published information on the diet of Cuvier's beaked whales Ziphius cavirostris (Odontoceti: Ziphiidae) is reviewed and new information on the stomach contents of three animals: two stranded in Galicia (north-west Spain) in February 1990 at A Lanzada, and in February 1995 at Portonovo; and the third stranded in February 1999 in North Uist (Scotland), is presented. The whale stranded in 1990 was a male; the other two were adult females. All animals were >5 m long. The limited published information on the diet of this species indicates that it feeds primarily on oceanic cephalopods although some authors also found remains of oceanic fish and crustaceans. Food remains from the three new samples consisted entirely of cephalopod beaks. The Scottish sample set is the largest recorded to date for this species. The prey identified consisted of oceanic cephalopods, mainly squid (Cephalopoda: Teuthoidea). The most frequently occurring species were the squid Teuthowenia megalops, Mastigoteuthis schmidti and Taoniuspavo (for the Galician whale stranded in 1990), Teuthowenia megalops and Histioteuthis reversa (for the second Galician whale) and T. megalops, Gonatus sp. and Taoniuspavo (for the Scottish whale). Other prey included the squid Histioteuthis bonnellii, Histioteuthis arcturi and Todarodes sagittatus as well as Vampiroteuthis infernalis (Cephalopoda: Vampyromorpha), Stauroteuthis syrtensis and Japetella diaphana (Cephalopoda: Octopoda). The squid eaten (estimated from the measurement of the lower beaks) included juvenile and mature individuals of the most important species (Teuthowenia megalops, Gonatus sp.). The range of species found in the diet of Z. cavirostris is greater than that reported for sperm whales and bottlenosed whales in the north-east Atlantic.

Diet of Cuvier’s beaked whales Ziphius cavirostris from the North Pacific and a comparison with their diet world-wide

“…Ancistrocheirids have previously been identified from specimens in the North Atlantic and the Mediterranean (Podesta & Meotti 1991, Carlini et al 1992, Santos et al 2007). The family Cycloteuthidae has also been previously reported from the Atlantic (Santos et al 2001, Spitz et al 2011), but was identified for the first time from the North Pacific in negligible amounts (<1%). We also confirmed that Mastigoteuthidae contributes negligibly (<1%) to the North Pacific diet, while it is more important to the diet of whales in the North Atlantic (Table 3; Santos et al 2001).…”

“…They also contributed more to the diet by mass in previously examined specimens from California (83.0%) and Japan (91.8%) (Ohizumi & Kishiro 2003, Adams et al 2015 and contributed 8.1% and 51.8% to the diet by mass from 2 Alaskan whales (Foster & Hare 1990, Fiscus 1997. Gonatid squids are also recognized as being important to Cuvier's beaked whale diet in the North Atlantic (Santos et al 2001, Spitz et al 2011), albeit to a lesser degree than observed in North Pacific whales. Gonatidae contributed less than 2% by number in South Africa (Ross 1984, Sekiguchi 1994).…”

“…Prey identification from stomach content analysis has only been conducted for fewer than 50 individuals world-wide, with a bias of approximately 65% towards males. The majority of Cuvier's beaked whale stomachs examined have come from stranded specimens in the North Atlantic (n = 20) or Mediterranean (n = 12), where findings have been reported in a number of separate studies (Podesta & Meotti 1991, Carlini et al 1992, Blanco & Raga 2000, Lefkaditou & Poulo poulos 1998, Santos et al 2001, Spitz et al 2011. When considering the total number of prey items identified among Cuvier's beaked whales examined world-wide, the data available are heavily weighted towards the North Atlantic.…”

“…When considering the total number of prey items identified among Cuvier's beaked whales examined world-wide, the data available are heavily weighted towards the North Atlantic. Over 8000 prey items were identified from an individual specimen stranded near Scotland (Santos et al 2001), and prey was identified from 10 specimens stranded over a 10 yr period in the Bay of Biscay (Spitz et al 2011) and from 7 specimens stranded in the Canary Islands (Santos et al 2007). In the Southern Hemisphere, Cuvier's beaked whale stomach content remains have been identified from 5 individuals from South Africa (Ross 1984, Sekiguchi 1994) and 1 whale from New Zealand (Fordyce et al 1979).…”

Spatial variability of deep scattering layers shapes the Bahamian mesopelagic ecosystem

“…being the dominant taxonomic groups. These animals feed on phytoplankton, small zooplankton, and detritus (Mauch line 1980b, Karuppasamy & Menon 2004, Bernal et al 2015 and are common prey for the large mesopelagic fishes and cephalopods (Nigma tullin et al 2001, Choy et al 2013) that are primary prey for the Blainville's beaked whales (Santos et al 2001, Hickmott 2005. The constant frequency res ponse throughout the day and coherent movement of these layers support the conclusion that species composition within each layer type remained the same between day and night despite the lack of trawl information at night.…”