First Record of Pygmy Killer Whales (Feresa attenuata) in the Gulf of California, Mexico: Diet Inferences and Probable Relation with Warm Conditions During 2014

Elorriaga‐Verplancken, Fernando R.; Rosales‐Nanduca, Hiram; Paniagua-Mendoza, Aurora; Martínez‐Aguilar, Sergio; Nader-Valencia, Ana K.; Robles-Hernández, Roberto; Gómez-Díaz, Francisco; Urbán, R Jorge

doi:10.1578/am.42.1.2016.20

Cited by 11 publications

(5 citation statements)

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“…However, stomach contents revealed few prey remains. In contrast, stomach contents have commonly been reported at previous strandings involving this species and suggest a diet of cephalopods and fish (Elorriaga‐Verplancken et al, 2016; Leatherwood & Reeves, 1989; Mignucci‐Giannoni et al, 2000; O'Dwyer et al, 2015; Zerbini & de Oliveira Santos, 1997). Similarly, previous studies of other blackfish delphinids (long‐finned pilot whales, Globicephala melas edwardii ) in New Zealand have also commonly found recently ingested prey (Beatson & O'Shea 2009; Beatson et al, 2007, 2010; Hinton, 2023).…”

Section: Discussionmentioning

confidence: 81%

Assessing animal welfare during a stranding of pygmy killer whales (Feresa attenuata)

Boys

Beausoleil

Hunter

et al. 2023

Marine Mammal Science

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Empirical assessment of cetacean welfare to inform stranding interventions is lacking. Here, potential welfare indicators are described for two stranded pygmy killer whales (Feresa attenuata), along with euthanasia procedures and pathology of potential relevance. The animals were filmed for 3.5 and 1.5 hr, respectively, allowing assessment of 19 indicators, including animal behaviors and human interventions. Eight interventions and 19 animal behaviors were identified; 17 and 11 behaviors were displayed by animal 1 and 2, respectively. Examination of ballistics euthanasia revealed atypical projectile placement and characterized animal behavioral responses, but welfare implications could not be assessed as insensibility was not verified in‐field. Pulmonary edema and renal degeneration were documented in both animals; differential etiologies include ischemia–reperfusion, shock, and/or myopathy. Potential relationships among histopathology and welfare indicators are explored to infer affective experiences. For example, simultaneous head‐lifting with respiration increased over time which, alongside pulmonary edema, suggests these animals experienced breathlessness. Other likely affective states include fatigue and discomfort; there are insufficient data to estimate the intensity or duration of these experiences or to provide an overall welfare grade/score. Further data are required to validate the proposed welfare indicators and to progress development of holistic approaches to welfare assessment at cetacean strandings.

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Section: Discussionmentioning

confidence: 81%

Assessing animal welfare during a stranding of pygmy killer whales (Feresa attenuata)

Boys

Beausoleil

Hunter

et al. 2023

Marine Mammal Science

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show abstract

“…Once deceased, individuals PKW2 and PKW3 were recovered by NOAA Fisheries and post-mortem examinations were conducted at the University of Hawaii Health and Stranding Laboratory. Stomach content analyses suggested abnormal foraging efforts that are outside of the expected diet of pygmy killer whales, which is thought to be primarily cephalopods 44 . Individual PKW2 had remains of small unidentifiable fish and both marine and terrestrial plant material.…”

Section: Resultsmentioning

confidence: 99%

“…Here, we show that free-ranging pygmy killer whales lost ~ 2% of their body mass per day when they ceased normal foraging. The diet of pygmy killer whales in Hawaiian waters is unknown but cephalopods have been described as the dominant dietary item from stranded pygmy killer whales off of the Gulf of California, Mexico 44 and were absent among the stomach contents of PKW2 and PKW3. The rate of weight loss as a result of feeding disruption has previously been studied for captive harbor porpoises ( Phocoena phocoena ) where animals lost 1.3–2.4 kg/day or approximately 4% of their total body mass 17 .…”

Section: Discussionmentioning

confidence: 99%

Rapid weight loss in free ranging pygmy killer whales (Feresa attenuata) and the implications for anthropogenic disturbance of odontocetes

Currie¹,

Aswegen

Stack³

et al. 2021

Sci Rep

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Understanding the impacts of foraging disruptions to odontocete body condition is fundamental to quantifying biological effects of human disturbance and environmental changes on cetacean populations. Here, reductions in body volume of free-ranging pygmy killer whales (Feresa attenuata) were calculated using repeated measurements of the same individuals obtained through Unoccupied Aerial System (UAS)-photogrammetry during a prolonged disruption in foraging activity arising from a 21-day stranding event. Stranded individuals were used to verify UAS-derived volume and length estimates through 3D-imaging, water displacement, and post-mortem measurements. We show that (a) UAS estimates of length were within 1.5% of actual body length and UAS volume estimates were within 10–13% of actual volume, (b) foraging disruption resulted in a daily decrease of 2% of total body mass/day, and (c) pygmy killer whales can lose up to 27% of their total body weight within 17 days. These findings highlight the use of UAS as a promising new method to remotely monitor changes in body condition and animal health, which can be used to determine the potential effects of anthropogenic disturbance and environmental change on free-ranging odontocetes.

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“…These same authors suggested that changes in distribution and abundance of pantropical spotted dolphins would be associated with habitat changes during 2014 and 2016 related to extratropical (The Blob) and tropical (ENSO) oceanographic phenomena respectively, which could have modulated their foraging activities. Other anomalous events occurred during 2014, including the observation of pygmy killer whale ( Feresa attenuata ) for the first time in the Gulf of California, and a stranding event (Elorriaga‐Verplancken et al, 2016).…”

Section: Figurementioning

confidence: 99%

Ecological aspects of false killer whales (Pseudorca crassidens) from Mexican Pacific and Southern California waters

Lazcano‐Pacheco,

Castillo‐Sánchez,

Ortega‐Ortiz

et al. 2023

Marine Mammal Science

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First Record of Pygmy Killer Whales (Feresa attenuata) in the Gulf of California, Mexico: Diet Inferences and Probable Relation with Warm Conditions During 2014

Cited by 11 publications

References 0 publications

Assessing animal welfare during a stranding of pygmy killer whales (Feresa attenuata)

Assessing animal welfare during a stranding of pygmy killer whales (Feresa attenuata)

Rapid weight loss in free ranging pygmy killer whales (Feresa attenuata) and the implications for anthropogenic disturbance of odontocetes

Ecological aspects of false killer whales (Pseudorca crassidens) from Mexican Pacific and Southern California waters

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