A Theoretical Approach To Assessing Annual Energy Balance In Gray Whales (eschrichtius Robustus)
While direct measurements of energetic demands are nearly impossible to collect on large cetaceans, comprehensive bioenergetic models can give insights on such parameters by combining physiological and ecological knowledge. This model was developed to estimate necessary food intake of gray whales, E...
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ftunicentralflor:oai:stars.library.ucf.edu:etd-1328 2023-05-15T15:43:58+02:00 A Theoretical Approach To Assessing Annual Energy Balance In Gray Whales (eschrichtius Robustus) Greenwald, Nathalie Lucie Elizabeth 2005-01-01T08:00:00Z application/pdf https://stars.library.ucf.edu/etd/329 https://stars.library.ucf.edu/cgi/viewcontent.cgi?article=1328&context=etd English eng STARS https://stars.library.ucf.edu/etd/329 https://stars.library.ucf.edu/cgi/viewcontent.cgi?article=1328&context=etd Electronic Theses and Dissertations energetic costs BMR gray whale Eschrichtius robustus model simulations Biology text 2005 ftunicentralflor 2021-12-21T11:24:16Z While direct measurements of energetic demands are nearly impossible to collect on large cetaceans, comprehensive bioenergetic models can give insights on such parameters by combining physiological and ecological knowledge. This model was developed to estimate necessary food intake of gray whales, Eschrichtius robustus, of the Eastern North Pacific stock. Field Metabolic Rates (FMR) for gray whales were first estimated based on various assumptions (e.g. volumetric representation of gray whales, extent of their feeding season, and blubber depth distribution) using morphometric data, energetic costs, and food assimilation according to age and gender specific requirements. Food intake rates for gray whales of varying maturity and gender were then estimated based on FMR and caloric value of prey and compared to food intake rates of previous studies. Monte Carlo simulations and sensitivity analysis were performed to assess the model's predictions compared to observed field data from previous studies. Predicted average food intakes for adult male, pregnant/ lactating female, and immature whales were 475 ± 300, 525 ± 300 and 600 ± 300 kg d-1, respectively. Estimated blubber depths resulting from these food intakes were comparable to field data obtained from whaling data. Sensitivity analysis indicated food intake, from all parameters, as having the highest impact on the percent change in ending mass from a simulation. These food intake estimates are similar to those found in a previous study and fall within the range of food intake per body mass observed in other species of cetaceans. Though thermoregulation can be a factor in some cetaceans, it appears not to be an additional cost for gray whales as the present model's predicted lower critical temperatures for the whales (TLC) were below ambient temperatures. With temperatures increasing in the Bering Sea, the main prey of gray whales, ampeliscid amphipods, could be adversely affected, possibly resulting in increased food shortages leading to a surge in gray whale strandings. Text Bering Sea University of Central Florida (UCF): STARS (Showcase of Text, Archives, Research & Scholarship) Bering Sea Pacific |
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University of Central Florida (UCF): STARS (Showcase of Text, Archives, Research & Scholarship) |
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ftunicentralflor |
language |
English |
topic |
energetic costs BMR gray whale Eschrichtius robustus model simulations Biology |
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energetic costs BMR gray whale Eschrichtius robustus model simulations Biology Greenwald, Nathalie Lucie Elizabeth A Theoretical Approach To Assessing Annual Energy Balance In Gray Whales (eschrichtius Robustus) |
topic_facet |
energetic costs BMR gray whale Eschrichtius robustus model simulations Biology |
description |
While direct measurements of energetic demands are nearly impossible to collect on large cetaceans, comprehensive bioenergetic models can give insights on such parameters by combining physiological and ecological knowledge. This model was developed to estimate necessary food intake of gray whales, Eschrichtius robustus, of the Eastern North Pacific stock. Field Metabolic Rates (FMR) for gray whales were first estimated based on various assumptions (e.g. volumetric representation of gray whales, extent of their feeding season, and blubber depth distribution) using morphometric data, energetic costs, and food assimilation according to age and gender specific requirements. Food intake rates for gray whales of varying maturity and gender were then estimated based on FMR and caloric value of prey and compared to food intake rates of previous studies. Monte Carlo simulations and sensitivity analysis were performed to assess the model's predictions compared to observed field data from previous studies. Predicted average food intakes for adult male, pregnant/ lactating female, and immature whales were 475 ± 300, 525 ± 300 and 600 ± 300 kg d-1, respectively. Estimated blubber depths resulting from these food intakes were comparable to field data obtained from whaling data. Sensitivity analysis indicated food intake, from all parameters, as having the highest impact on the percent change in ending mass from a simulation. These food intake estimates are similar to those found in a previous study and fall within the range of food intake per body mass observed in other species of cetaceans. Though thermoregulation can be a factor in some cetaceans, it appears not to be an additional cost for gray whales as the present model's predicted lower critical temperatures for the whales (TLC) were below ambient temperatures. With temperatures increasing in the Bering Sea, the main prey of gray whales, ampeliscid amphipods, could be adversely affected, possibly resulting in increased food shortages leading to a surge in gray whale strandings. |
format |
Text |
author |
Greenwald, Nathalie Lucie Elizabeth |
author_facet |
Greenwald, Nathalie Lucie Elizabeth |
author_sort |
Greenwald, Nathalie Lucie Elizabeth |
title |
A Theoretical Approach To Assessing Annual Energy Balance In Gray Whales (eschrichtius Robustus) |
title_short |
A Theoretical Approach To Assessing Annual Energy Balance In Gray Whales (eschrichtius Robustus) |
title_full |
A Theoretical Approach To Assessing Annual Energy Balance In Gray Whales (eschrichtius Robustus) |
title_fullStr |
A Theoretical Approach To Assessing Annual Energy Balance In Gray Whales (eschrichtius Robustus) |
title_full_unstemmed |
A Theoretical Approach To Assessing Annual Energy Balance In Gray Whales (eschrichtius Robustus) |
title_sort |
theoretical approach to assessing annual energy balance in gray whales (eschrichtius robustus) |
publisher |
STARS |
publishDate |
2005 |
url |
https://stars.library.ucf.edu/etd/329 https://stars.library.ucf.edu/cgi/viewcontent.cgi?article=1328&context=etd |
geographic |
Bering Sea Pacific |
geographic_facet |
Bering Sea Pacific |
genre |
Bering Sea |
genre_facet |
Bering Sea |
op_source |
Electronic Theses and Dissertations |
op_relation |
https://stars.library.ucf.edu/etd/329 https://stars.library.ucf.edu/cgi/viewcontent.cgi?article=1328&context=etd |
_version_ |
1766378186666409984 |