Gizzard and other lean mass components increase, yet Basal Metabolic Rates decrease, when red knots Calidris canutus are shifted from soft to hard‐shelled food

We measured basal metabolic rate (BMR), body mass, lean mass, and gizzard mass of captive red knots Calidris canutus islandica maintained on a trout chow diet (soft‐texture, low ash and water content) for several years and then shifted to small mussels Mytilus edulis (hard‐texture, high ash and wate...

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Bibliographic Details
Published in:Journal of Avian Biology
Main Authors: Piersma, Theunis, Gessaman, James A., Dekinga, Anne, Visser, G. Henk
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2004
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Online Access:http://dx.doi.org/10.1111/j.0908-8857.2004.03259.x
https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.0908-8857.2004.03259.x
https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.0908-8857.2004.03259.x
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Summary:We measured basal metabolic rate (BMR), body mass, lean mass, and gizzard mass of captive red knots Calidris canutus islandica maintained on a trout chow diet (soft‐texture, low ash and water content) for several years and then shifted to small mussels Mytilus edulis (hard‐texture, high ash and water content). During a 3‐week period of feeding on mussels, body mass, lean mass, and gizzard mass increased 7.3 g (+7%), 10.5 g (+12%), and 4.9 g (+213%), respectively, yet BMR decreased from 0.96 to 0.89 W (−8%). Under the new mussel regime, red knots must have reduced the metabolic intensity of some of the tissues. This suggests that the experimental red knots experienced the transition to a mussel diet as stressful and energy limiting, resulting in an energy‐saving strategy by reducing BMR in spite of hypertrophy of the gizzard and other organs.