Publications by authors named "Jessica E Deakin"

Bird flight muscle can lose as much as 20% of its mass during a migratory flight due to protein catabolism, and catabolism can be further exacerbated under dehydrating conditions. However, the functional consequences of exercise and environment induced protein catabolism on muscle has not been examined. We hypothesized that prolonged flight would cause a decline in muscle mass, aerobic capacity, and contractile performance.

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Fat is the major fuel for migratory flight of birds, but protein is also catabolized. Flight range could be reduced if protein is used too quickly from muscles and organs, and it is important to understand factors that influence protein catabolism. Previous correlative studies suggested high protein diets may increase protein use in flight, although a wind tunnel study with yellow-rumped warblers (Setophaga coronata) did not support this relationship.

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Cost of flight at various speeds is a crucial determinant of flight behaviour in birds. Aerodynamic models, predicting that mechanical power () varies with flight speed in a U-shaped manner, have been used together with an energy conversion factor (efficiency) to estimate metabolic power () Despite few empirical studies, efficiency has been assumed constant across flight speeds at 23%. Ideally, efficiency should be estimated from measurements of both and in un-instrumented flight Until recently, progress has been hampered by methodological constraints.

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Migratory birds use protein as a fuel source during flight, but the mechanisms and benefits of protein catabolism during migration are poorly understood. The tissue-specific turnover rate hypothesis proposes that lean mass loss depends solely on the constitutive rate of protein degradation for a given tissue, and is therefore independent of metabolic rate or environmental stimuli. However, it has been demonstrated that environmental stressors such as humidity affect the rate of lean mass catabolism during flight, a finding that seemingly contradicts the tissue-specific turnover rate hypothesis.

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