Influence of body composition on the metabolic rate of nestling European shags ( Phalacrocorax aristotelis )

Developmental plasticity of physiology and morphology in diet-restricted European shag nestlings (Phalacrocorax aristotelis)

“…Mass-specific RMR is very high during this age period (Bech and Østnes, 1999;Østnes et al, 2001). We reveal whether nestling European shags exhibit any energy saving that can lessen the detrimental effects of reduced food intake during early development, and reveal how the nestlings allocated the energy between maintenance and growth.…”

“…In our study, the mass of the liver, the pectoral muscles and the lipid mass were positively correlated to RMR. Liver tissue has a high intrinsic MR (Scott and Evans, 1992), and Bech and Østnes (1999) suggested the liver to have a great influence on RMR of nestling European shags. In a study on metabolic responses to food-shortage, the liver size was a significant predictor of the differences in RMR between dietrestricted and ad libitum fed ducklings (Moe et al, in press).…”

“…Visceral organs (especially the heart, liver, kidneys and intestine) are believed to consume much of the energy used in basal metabolism (Daan et al, 1990), but the specific organs and tissues that predict RMR differ among studies (e.g. Burness et al, 1998;Bech and Østnes, 1999;Chappell et al, 1999;Moe et al, in press). Hence, it is not fully understood how body composition functionally relates to RMR.…”

“…As individual nestlings exhibit high growth rates (Østnes et al, 2001) and compete with siblings for food Velando et al, 1999Velando et al, , 2000, they depend on successful food provisioning rates to follow their normal developmental trajectory. Owing to a very low deposition of lipids (Bech and Østnes, 1999), the nestlings have a limited capacity for buffering temporal food shortages. In the study area, the European shag is an inshore and offshore benthic feeder, and relies on gadoids (Barrett et al, 1990).…”

Acclimation to different thermal conditions in a northerly wintering shorebird is driven by body mass-related changes in organ size

“…Indeed, BMR variability is frequently found to reflect the size of other metabolically active organs [see table 1 (Piersma, 2002)], with specific organs that relate to BMR differing through time or physiological state (Vézina and Williams, 2005). Several studies on birds showed positive correlations between BMR and the mass of organs involved in digestive function, notably the liver, intestine, stomach, gizzard and kidney (Bech and Ostnes, 1999;Chappell et al, 1999;Burness et al, 1998;Hammond et al, 2000;Williams and Tieleman, 2000;Vézina and Williams, 2003). The masses of the heart and, in some cases, pectoral muscles and lungs, have also been related to variations in BMR (Daan et al, 1990;Weber and Piersma, 1996;Chappell et al, 1999;Hammond et al, 2000;Vézina and Williams, 2003).…”