Short Note: First Report of Killer Whales Harassing Sperm Whales in the Gulf of Mexico

Whitt, Amy D.; Baran, Melody A.; Bryson, Maurice C.; Rendell, Luke

doi:10.1578/am.41.3.2015.252

Cited by 5 publications

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Given our observations of interactions with marine mammals, we cannot exclude the possibility that marine mammal specialist killer whales [15] occur in Icelandic waters. Some of the whales observed off Húsavík attacking a minke whale had narrow and fainter coloured saddle patches, which were similar to those described in other regions (Hawaii [82]; Caribbean [83]; Gulf of Mexico [84]) but unlike most saddle patches in an existing photo-identification catalogue [24]. However, this feature was not shared among all individuals involved in the event suggesting they were not of a single morphotype.…”

Section: Discussionmentioning

confidence: 55%

Prey of killer whales (Orcinus orca) in Iceland

Samarra

Bassoi²,

Béesau

et al. 2018

PLoS ONE

View full text Add to dashboard Cite

Killer whales have a cosmopolitan distribution and as a species are generalists, feeding on a variety of prey. However, local populations tend to specialise on specific prey types. In Icelandic waters, killer whales are generally associated with herring and, thus, have been presumed to be herring specialists. However, recent studies suggest a more complex foraging ecology, possibly including a mosaic of strategies. With increased observational effort in recent years due to research and whale-watching activities, there have been several reports of interactions with different prey, including confirmed predation events. In this study we aimed to summarise the range of potential prey of killer whales observed in Icelandic waters. We report on 12 previously unpublished accounts and review 15 accounts published in the scientific literature or local newspapers, making a total of 27 events where killer whales were observed interacting with actual or potential prey. Thirteen different species, including birds (n = 1), cephalopods (n = 1), fish (n = 5) and marine mammals (n = 6), are reported, although herring is by far the species that killer whales are most often observed interacting with. This study provides the first summary of actual and suspected killer whale prey in Icelandic waters, and contributes towards our understanding of this population’s prey preferences. However, describing the diet of individuals/groups was not possible and this study points to a need for continued monitoring to understand the intricacies of killer whale foraging behaviour in this area.

show abstract

Section: Discussionmentioning

confidence: 55%

Prey of killer whales (Orcinus orca) in Iceland

Samarra

Bassoi²,

Béesau

et al. 2018

PLoS ONE

View full text Add to dashboard Cite

show abstract

“…Predation: While the threat of predation from orcas ( Orcinus orca ) is thought to be higher in the Pacific [ 42 ], recent observations suggest predation occurs in the Gulf of Mexico [ 43 ], around the Caribbean [ 44 ], and off Dominica (S.Gero, unpublished data).…”

Section: Discussionmentioning

confidence: 99%

Critical Decline of the Eastern Caribbean Sperm Whale Population

Gero

Whitehead

2016

PLoS ONE

View full text Add to dashboard Cite

Sperm whale (Physeter macrocephalus) populations were expected to rebuild following the end of commercial whaling. We document the decline of the population in the eastern Caribbean by tracing demographic changes of well-studied social units. We address hypotheses that, over a ten-year period of dedicated effort (2005–2015), unit size, numbers of calves and/or calving rates have each declined. Across 16 units, the number of adults decreased in 12 units, increased in two, and showed no change in two. The number of adults per unit decreased at -0.195 individuals/yr (95% CI: -0.080 to -0.310; P = 0.001). The number of calves also declined, but the decline was not significant. This negative trend of -4.5% per year in unit size started in about 2010, with numbers being fairly stable until then. There are several natural and anthropogenic threats, but no well-substantiated cause for the decline.

show abstract

“…Particularly in the Eastern North Pacific (ENP, a region encompassing from the Gulf of Alaska to the Baja California Peninsula, Mexico), three KW ecotypes have been described based on distribution patterns, behavior, morphology, acoustics, and feeding preferences: fish‐eating “residents,” mammal‐eating “transients,” and mammal large/fish‐eating “offshore” (Baird, 2000; Baird & Stacey, 1988; Dahlheim et al, 2008; Foote & Nystuen, 2008; Ford et al, 1998). Although there has been an increase in published reports on KW from tropical/subtropical regions in recent years (e.g., Bolaños‐Jiménez et al, 2014; Pitman et al, 2015; Rankin, Archer, & Barlow, 2013; Testino et al, 2019; Weir, Collins, Carvalho, & Rosenbaum, 2010; Whitt, Baran, Bryson, & Rendell, 2015), information on individuals distributed in the Eastern Tropical Pacific (ETP, from the southern Baja California Peninsula, Mexico, to northern Peru, including offshore waters towards Hawaii), is still scarce (Dahlheim, Leatherwood, & Perrin, 1982; García‐Godos, 2004; Guerrero‐Ruiz, Gendron, & Urbán, 1998; Hamilton et al, 2009), and none of the ecotypes have been recognized in this area (Olson & Gerrodette, 2008). Through data interpretation of surveys conducted during 1986–2005 from National Oceanic and Atmospheric Administration (NOAA), it seems that KW do not separate into distinct populations in the ETP; instead, they seem to be broadly and thinly distributed over the entire area (Hamilton et al, 2009).…”

Section: Figurementioning

confidence: 99%

Ecological aspects of killer whales from the Mexican Central Pacific coast: Revealing a new ecotype in the Eastern Tropical Pacific

Vargas-Bravo

Elorriaga‐Verplancken

Olivos-Ortíz

et al. 2020

Marine Mammal Science

View full text Add to dashboard Cite

The killer whale (KW, Orcinus orca) is the most cosmopolitan species among cetaceans (Bryun, Tosh, & Terauds, 2012;Heyning & Dahlheim, 1988), showing a unique global population genetic structure among nonhuman species (Foote et al., 2019). Its widespread distribution, along with its top predator status (Mehta et al., 2007), make it a good indicator of alterations in the marine trophic structure (Moore, 2008). Although the KW has been extensively studied over the past several decades, it is still classified as "Data deficient" in the Red List of the International Union for Conservation of Nature, as many populations are still scarcely known (Reeves, Pitman, & Ford, 2017).

show abstract

Short Note: First Report of Killer Whales Harassing Sperm Whales in the Gulf of Mexico

Cited by 5 publications

References 0 publications

Prey of killer whales (Orcinus orca) in Iceland

Prey of killer whales (Orcinus orca) in Iceland

Critical Decline of the Eastern Caribbean Sperm Whale Population

Ecological aspects of killer whales from the Mexican Central Pacific coast: Revealing a new ecotype in the Eastern Tropical Pacific

Contact Info

Product

Resources

About