Leaner leviathans: body condition variation in a critically endangered whale population

Bradford, Amanda L.; Weller, David W.; Punt, André E.; Ivashchenko, Yulia V.; Burdin, Alexander M.; VanBlaricom, Glenn R.; Brownell, Robert L.

doi:10.1644/11-mamm-a-091.1

Cited by 80 publications

(113 citation statements)

References 59 publications

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“…Mobilization of blubber lipids in right whales has been documented both quantitatively and qualitatively, and manifests visually by marked changes in the lateral and dorsal back profile (Pettis et al 2004, Rolland et al 2007b, Miller et al 2011. Bradford et al (2012) described similar changes in visual body condition in western gray whales Eschrichtius robustus, with lactating females in relatively worse body condition than other whales and most often observed with compromised condition. Here we have shown that the energetic drain associated with lactation in right whales is significant enough to be detected visually, and that it can be detected quite rapidly.…”

Section: Reproductive Statementioning

confidence: 94%

“…Body condition, a metric used to estimate relative energetic reserves, has been correlated with survival and reproductive success of both terrestrial (Young 1976, Schulte-Hostedde et al 2001) and marine mam -mals (Lockyer 1986, 1993, Pitcher et al 1998, Hall et al 2001, Pettis et al 2004, Rolland et al 2007b, Miller et al 2011 and is often used to assess and monitor the overall health of animal populations (Beck et al 1993, Gerhart et al 1996, Pitcher et al 1998, Bradford et al 2012, Williams et al 2013. In large whale species, energetic reserves are stored in, and mobilized from, the blubber layer, visceral tissues, and muscles (Lockyer et al 1985, Aguilar & Borrell 1990, Niaess et al 1998, and thus characteristics of these tissues, including thickness and chemical composition, are considered to be primary indicators of overall body condition (Lockyer et al 1985, Miller et al 2011.…”

Section: Introductionmentioning

confidence: 99%

“…Standard means of assessing the body condition of marine mammals, including live capture or direct post mortem measurements (Lockyer et al 1985, Beck et al 1993, Nilssen et al 2001, Koopman et al 2002, Wells et al 2004) are inappropriate for tracking individual and population-wide health in rare, free-ranging large whale species. The development and application of several new methods, such as ultrasonic measurement of blubber thickness (Moore et al 2001, Angell 2005, Miller et al 2011, vertical aerial photogrammetric measurements of length and width (Perryman & Lynn 2002) and visual assessments of body contours (Pettis et al 2004, Bradford et al 2012) have allowed researchers to document correlations between changes in body condition and periods of known energetic stress and recovery in large whale species, including right whales (Perryman & Lynn 2002, Pettis et al 2004, Rolland et al 2007b, Miller et al 2011, Bradford et al 2012.…”

Section: Introductionmentioning

confidence: 99%

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Body condition changes arising from natural factors and fishing gear entanglements in North Atlantic right whales Eubalaena glacialis

Pettis¹,

Rolland²,

Hamilton³

et al. 2017

Endang. Species. Res.

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Body condition has been correlated with survival and reproductive success in both terrestrial and marine mammals, including North Atlantic right whales Eubalaena glacialis. We used photographs of individually identified right whales to assess visual changes in body condition in reproductive females, adult males, juveniles, and entangled whales. Images from sightings of individual whales were grouped sequentially by habitat region, and each group of images was assigned a body condition score of good, fair, or poor based on the dorsal profile posterior to the blowholes. Temporally consecutive groups of images (n = 1496) of 340 individual whales were compared to investigate the frequency, direction, and minimum timeframe between changes in body condition. Changes in body condition scores of right whales were significantly influenced by group category. Lactating females and severely entangled right whales were more likely to exhibit declining body condition than other groups. Resting females were significantly more likely to improve in condition than other groups but exhibited the longest timeframe for improving condition. Young juveniles were less likely to improve in condition compared to adult males, but remained in compromised condition less frequently than older juveniles and adult males. The shortest timeframes between changing body condition scores were 11 d for declining condition and 12 d for improving condition. This study demonstrates that photographic analysis can detect rapid body condition changes and identifies groups of right whales that are particularly vulnerable to declining condition and delayed recovery from energetically taxing events.

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Section: Reproductive Statementioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Body condition changes arising from natural factors and fishing gear entanglements in North Atlantic right whales Eubalaena glacialis

Pettis¹,

Rolland²,

Hamilton³

et al. 2017

Endang. Species. Res.

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show abstract

“…While these model analyses are focussed on right whales, photographic observations of condition have been used to evaluate health in other cetaceans (see, for example, Bradford et al 2012). It is feasible to extend this model to other well studied species, where photographic data may provide indicators of underlying health.…”

Section: Impact/applicationsmentioning

confidence: 99%

The Population Consequences of Disturbance Model Application to North Atlantic Right Whales (Eubalaena glacialis)

Kraus¹,

Rolland²,

Knowlton³

et al. 2014

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Award Number: N000141210389 http://tinyurl.com/RightWhaleResearch http://tinyurl.com/RightWhaleConservationMedicine LONG-TERM GOALSThe Population Consequences of Acoustic Disurbance (PCAD) model (NRC 2005) provided a framework to trace the effects of acoustic disturbance through the life history of a marine mammal to its population status. Developments in the model have been designed to determine if the effects of any disturbance can be traced from individuals to the population by way of changes in either behavior or physiology, and the revised approach is called PCOD (Population Consequences Of Disturbance). In North Atlantic right whales (Eubalaena glacialis), extensive data on health and body condition, anthropogenic impacts, and individual life history exists. The primary goal of this study is to model visual observations of health, human impacts (including entanglements and ship strikes), and whale locations to provide estimates of true underlying condition and individual level survival for right whales. Secondary goals include modeling fecundity, and exploring the feasibility of incorporating acoustic disturbance and prey variability into the PCOD model. OBJECTIVESThe objectives for this study are to: 1) develop a Hierarchical Bayesian Model to assess right whale biology, 2) assess the relationship between health indicators and reproduction and mortality in right whales, and 3) assess the effects of fishing gear entanglements and sub-lethal vessel strikes on reproduction and mortality in right whales. The objective for FY 2014 was to refine the model, compare model output with known right whale biology, and incorporate the model output on health and entanglements into publications for submission in the fall. APPROACHThe modeling approach is to link visual observations of health, human impacts, and whale locations to estimates of true underlying health and individual level survival (see Thomas et al. abstract). Visual

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“…gray whales - (Bradford et al 2012), the right whale analysis provides a framework for analyzing many different mammalian species -including humans. By using sporadic observations together with an underlying process model, we can infer how individuals are interacting with their environment, and how their health and condition is changing as a result.…”

Section: Impact/applicationsmentioning

confidence: 99%

Statistical Tools for Fitting Models of the Population Consequences of Acoustic Disturbance to Data from Marine Mammal Populations (PCAD Tools II)

Thomas

Harwood²,

Harris³

et al. 2012

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To build an ecological modeling framework that facilitates understanding of the at-sea condition and health of various species of marine mammals. This project will develop statistical tools to allow mathematical models of the population consequences of acoustic disturbance to be fitted to data from marine mammal populations. We will work closely with Phase II of the ONR PCAD Working Group, and will provide statistical support to that group. OBJECTIVESOur scientific objectives are to build a statistical framework for understanding the at-sea health of (initially) three species of marine mammals: southern and northern elephant seals, and northern right whales. Should the Working Group decide that we should address additional species, e.g. bottlenose dolphins, we will take those up in turn.For elephant seals our objective is to build a hierarchical Bayesian model that provides daily estimates of lipid status, as lipid status of the mother is directly linked to pup survival (McMahon et al. 2000). This model will use the drift dive behavior of elephant seals (Crocker et al. 1997) as the link to the underlying true, yet immeasurable, lipid state.For right whales, our objective is to build a model that provides spatially and temporally explicit estimates of individual health, movement, and survival. The model builds upon some of the ideas from the elephant seal project, but as the photo-identification of individual right whales is the core of the data, the model also includes many ideas concerning mark/recapture from .

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Leaner leviathans: body condition variation in a critically endangered whale population

Cited by 80 publications

References 59 publications

Body condition changes arising from natural factors and fishing gear entanglements in North Atlantic right whales Eubalaena glacialis

Body condition changes arising from natural factors and fishing gear entanglements in North Atlantic right whales Eubalaena glacialis

The Population Consequences of Disturbance Model Application to North Atlantic Right Whales (Eubalaena glacialis)

Statistical Tools for Fitting Models of the Population Consequences of Acoustic Disturbance to Data from Marine Mammal Populations (PCAD Tools II)

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