Short Note: Foraging Behavior of the Rough-Toothed Dolphin (Steno bredanensis) in Coastal Waters of the Mexican Central Pacific

Diel and lunar variation in diving behavior of rough‐toothed dolphins (Steno bredanensis) off Kauaʻi, Hawaiʻi

“…Combining observational work with tagging efforts provided insight into rough‐toothed dolphin diving behavior over different temporal periods. Our study and others (e.g., Lodi & Hetzel, 1999; Ortega‐Ortiz et al, 2014; Pitman & Stinchcomb, 2002; Ritter, 2002; Wedekin et al, 2004; Weir & Nicolson, 2014) have frequently documented rough‐toothed dolphins feeding on epipelagic prey species during the day. This is also consistent with prey identified from stomach content analyses of stranded animals (e.g., Di Beneditto et al, 2001; Ferrero et al, 1994; Layne, 1965; Ott & Denilewicz, 1996; Perrin & Walker, 1975; Shallenberger, 1981).…”

“…Observational studies have indicated that rough‐toothed dolphins frequently forage during the day, with notes of direct consumption, chasing, or herding epipelagic fish, and depredation of catch from fishing vessels (Baird, Webster, Mahaffy, et al, 2008; Gannier & West, 2005; Lodi & Hetzel, 1999; Ortega‐Ortiz et al, 2014; Pitman & Stinchcomb, 2002; Ritter, 2002; Wedekin et al, 2004; Weir & Nicolson, 2014). The only other foraging information on rough‐toothed dolphins comes from stomach contents from stranded animals, which contain epipelagic and coastal fish and cephalopod species (Clarke, 1986; Di Beneditto et al, 2001; Ferrero et al, 1994; Layne, 1965; Ott & Denilewicz, 1996; Perrin & Walker, 1975; Shallenberger, 1981; West et al, 2011).…”

Food sharing in rough‐toothed dolphins off southwestern Mexico

“…Rough‐toothed dolphins may have evolved cooperative hunting tactics to optimize hunting efficiency in capturing large prey similar to killer whales (Hoelzel, 1991; Pitman & Durban, 2012). Our observations and previous reports of rough‐toothed dolphin foraging also indicate these dolphins regularly target smaller prey fish and cooperatively hunt to herd fish schools and to feed on numerous fish at the same time for individual consumption (Addink & Smeek, 2001; Ortega‐Ortiz et al, 2014). Thus, food sharing in this species may have evolved as a tactic to improve food intake when targeting large and unpredictable prey, and as a means to reinforce social relationships between individuals.…”

“…Despite numerous reports of prey handling and cooperative feeding in rough‐toothed dolphins (Addink & Smeek, 2001; Götz, Verfuß, & Schnitzler, 2006; Ortega‐Ortiz et al, 2014; Pitman & Stinchcomb, 2002), to the best of our knowledge there are only two reported cases of food sharing in this species (Brower & Curtsinger, 1979) and one report of possible food sharing (Lodi & Hetzel, 1999). In the first case, in a group of 10 dolphins swimming slowly and close together, one dolphin deemed the “keeper” carried a large (~9 kg) mahi‐mahi ( Coryphaena hippurus ) crosswise in its mouth and shifting the fish to the corner of its mouth to “chew” it (likely ripping off a piece of flesh; Brower & Curtsinger, 1979).…”

Shallow‐water habitat use and population parameters of rough‐toothed dolphins, Steno bredanensis (G. Cuvier in Lesson, 1828) in southeastern Brazil

“…The rough‐toothed dolphin ( Steno bredanensis ) is a poorly studied delphinid species that occurs in tropical and subtropical oceans between 40°N and 35°S (West et al, 2011). Along this distribution, the species is usually found inhabiting deep waters with surface temperatures above 23°C (Jefferson et al, 2015; Ritter, 2002; Wells et al, 2008), but observations in coastal waters are also common (Addink & Smeenk, 2001; Kuczaj & Yeater, 2007; Lodi et al, 2012; Ortega‐Ortiz et al, 2014; Santos et al, 2019). Despite its wide distribution, most of the information regarding this species over the last decades has come from the Northern Hemisphere (Addink & Smeenk, 2001; Baird et al, 2008; Barlow, 2006; Ferrero & Hodder, 1994; Jefferson et al, 2006; Kuczaj & Yeater, 2007; Ortega‐Ortiz et al, 2014; Rankin et al, 2015; Ritter, 2002, 2007; Struntz et al, 2004; Watkins et al, 1987; Wells et al, 2008).…”