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Quantifying the energy stores of capital breeding humpback whales and income breeding sperm whales using historical whaling records

View Article: PubMed Central - PubMed

ABSTRACT

Cetacean energy stores are known to vary according to life history, reproductive status and time of year; however, the opportunity to quantify these relationships is rare. Using a unique set of historical whaling records from Western Australia (1952–1963), we investigated energy stores of large cetaceans with differing life histories, and quantified the relationship between total body lipid and length for humpback whales (Megaptera novaeangliae) (n = 905) and sperm whales (Physeter macrocephalus) (n = 1961). We found that total body lipid increased with body length in both humpback and sperm whales, consistent with size-related energy stores. Male humpback whales stored 2.49 kl (15.6 barrels) (31.9–74.9%) more lipid than male sperm whales of equivalent length, to fuel their annual migration. Relative lipid stores of sperm whales (males) were constant throughout the year, while those of humpback whales varied with reproductive class and sampling date. Pregnant female humpback whales had higher relative energy stores than non-pregnant females and males (26.2% and 37.4%, respectively), to fuel the energy demands of gestation and lactation. Those that reached the sampling site later (en route to their breeding grounds) carried higher lipid stores than those that arrived earlier, possibly reflecting individual variation in residency times in the Antarctic feeding grounds. Importantly, longer pregnant females had relatively larger energy stores than the shorter pregnant females, indicating that the smaller individuals may experience higher levels of energetic stress during the migration fast. The relationships we developed between body lipid and length can be used to inform bioenergetics and ecosystem models when such detailed information is not available.

No MeSH data available.


Related in: MedlinePlus

Relationship between humpback whale total body lipid and the predictors in the top-ranked model (length and reproductive class) from the suite of models tested to explain total body lipid. Shown are the raw values, fitted lines and regression equations for each reproductive class. Immature whales are colour-coded with non-filled centres: immature females with a red outline and immature males with a black outline.
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RSOS160290F4: Relationship between humpback whale total body lipid and the predictors in the top-ranked model (length and reproductive class) from the suite of models tested to explain total body lipid. Shown are the raw values, fitted lines and regression equations for each reproductive class. Immature whales are colour-coded with non-filled centres: immature females with a red outline and immature males with a black outline.

Mentions: The highest ranked model included length and reproductive class and the interaction between them (wAICc = 1) (table 3), demonstrating that there was a positive relationship between total body lipid and length in all reproductive classes. The slope differed according to reproductive class, with that of the pregnant females being the steepest (y = 2.30x – 18.8), followed by non-pregnant females (y = 1.31x – 7.9) and then males (y = 1.19x – 6.8) (figure 4).Figure 4.


Quantifying the energy stores of capital breeding humpback whales and income breeding sperm whales using historical whaling records
Relationship between humpback whale total body lipid and the predictors in the top-ranked model (length and reproductive class) from the suite of models tested to explain total body lipid. Shown are the raw values, fitted lines and regression equations for each reproductive class. Immature whales are colour-coded with non-filled centres: immature females with a red outline and immature males with a black outline.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5383807&req=5

RSOS160290F4: Relationship between humpback whale total body lipid and the predictors in the top-ranked model (length and reproductive class) from the suite of models tested to explain total body lipid. Shown are the raw values, fitted lines and regression equations for each reproductive class. Immature whales are colour-coded with non-filled centres: immature females with a red outline and immature males with a black outline.
Mentions: The highest ranked model included length and reproductive class and the interaction between them (wAICc = 1) (table 3), demonstrating that there was a positive relationship between total body lipid and length in all reproductive classes. The slope differed according to reproductive class, with that of the pregnant females being the steepest (y = 2.30x – 18.8), followed by non-pregnant females (y = 1.31x – 7.9) and then males (y = 1.19x – 6.8) (figure 4).Figure 4.

View Article: PubMed Central - PubMed

ABSTRACT

Cetacean energy stores are known to vary according to life history, reproductive status and time of year; however, the opportunity to quantify these relationships is rare. Using a unique set of historical whaling records from Western Australia (1952–1963), we investigated energy stores of large cetaceans with differing life histories, and quantified the relationship between total body lipid and length for humpback whales (Megaptera novaeangliae) (n = 905) and sperm whales (Physeter macrocephalus) (n = 1961). We found that total body lipid increased with body length in both humpback and sperm whales, consistent with size-related energy stores. Male humpback whales stored 2.49 kl (15.6 barrels) (31.9–74.9%) more lipid than male sperm whales of equivalent length, to fuel their annual migration. Relative lipid stores of sperm whales (males) were constant throughout the year, while those of humpback whales varied with reproductive class and sampling date. Pregnant female humpback whales had higher relative energy stores than non-pregnant females and males (26.2% and 37.4%, respectively), to fuel the energy demands of gestation and lactation. Those that reached the sampling site later (en route to their breeding grounds) carried higher lipid stores than those that arrived earlier, possibly reflecting individual variation in residency times in the Antarctic feeding grounds. Importantly, longer pregnant females had relatively larger energy stores than the shorter pregnant females, indicating that the smaller individuals may experience higher levels of energetic stress during the migration fast. The relationships we developed between body lipid and length can be used to inform bioenergetics and ecosystem models when such detailed information is not available.

No MeSH data available.


Related in: MedlinePlus