Basal metabolism of an adult male killer whale (Orcinus orca)

Abstract

Knowing how much energy an individual requires is fundamental to resolving a number of questions about the role an animal plays in its ecosystem. Various authors have used different approaches to assess energy needs of in situ (free-ranging) killer whales (Orcinus orca), including estimates based on observations of prey capture and consumption rates (e.g., Williams et al. 2004, Maniscalco et al. 2007 or extrapolations from bioenergetic models using data derived from ex situ (managed in zoological parks) individuals (e.g., Kastelein and Vaughan 1989, Kasting et al. 1989, Kriete 1995, Kastelein et al. 2003. The few measurements that have been made on ex situ killer whales include assessments of respiratory capabilities (e.g., Spencer et al. 1967, Kriete 1995, quantification of food/energy intake rates (e.g., Vaughan 1989, Kastelein et al. 2000a), or measures of metabolic rate (e.g., Kasting et al. 1989, Kriete 1995. These latter measurements have frequently not met the criteria of Kleiber (1975) due to whales being immature, pregnant, and/or active. The goals of the present study were to develop a functional methodology that could be employed to measure resting oxygen consumption rates of ex situ killer whales and obtain basal metabolic rate (BMR) measurements.The foundation of any bioenergetic model is an accurate assessment of BMR. They are not only used to estimate "resting" costs, but multiples of BMR are often used to estimate total field metabolic rates. Such models are important for estimating energy expenditures since it is difficult or impossible to acquire direct measures, especially for in situ whales, due to their large size and limited accessibility. Mass-balance simulation models have been used to estimate feeding requirements for some marine mammal species (e.g., Winship et al. 2002, Williams andNoren 2009), but because actual energetic measurements (including critical estimates of BMR) are impossible 1

Swimming and diving energetics in dolphins: a stroke-by-stroke analysis for predicting the cost of flight responses in wild odontocetes

“…This value was 2.7 times the predicted value based on Kleiber (1975), and follows trends for smaller odontocetes and other marine mammals (Williams et al, 2001;McNab, 2008). This differs from the results of Worthy et al (2014), who reported no difference between predicted values and measured basal metabolic rate for a 5318 kg male killer whale.…”

The significance of respiration timing in the energetics estimates of free-ranging killer whales (Orcinus orca)

“…Guinet et al (2007) estimated BMR using the equation provided by Motani (2002), taking into account an elevated BMR according to body mass, and obtained values similar to those used in the present study for both sexes. Extrapolated killer whale BMR measured by Worthy et al (2014) yielded values considerably lower than those used here for both sexes. Nevertheless, the sensitivity analyses indicated that this uncertainty did not change the main conclusions of our study.…”

“…Upper limits for the sensitivity analysis of this parameter (Table 1) were derived from the equation by Kasting et al (1989), which yielded relatively high BMR values compared with other studies on cetacean BMR. The lower limits were set according to recently found BMR values by Worthy et al (2014), which are relatively low compared with other cetacean BMR study outcomes.…”

“…Still, there exists a lack of solid values on energetic requirements of killer whales. The few studies that have been conducted on this species involving direct measurements of MR are based on a small number of animals and datasets (Kasting et al, 1989;Kriete, 1995;Worthy et al, 2014). Studies on the FMR of free-ranging animals have relied on respiration rates, assuming a constant E O2 .…”

Heart rates, heart rate profiles, and electrocardiograms in three killer whales, a beluga, and a pilot whale: An exploratory investigation

“…; Worthy et al . ). Indeed, measurements of metabolic rates of killer whales at rest were 1.1–2.7× the predicted Kleiber basal metabolic rate (Williams et al .…”