Fasting in Birds: General Patterns and the Special Case of Endurance Flight

摘要: Birds undergo among the most extraordinary fasting events which may last up to several months as in breeding or moulting penguins during subantarctic winter more than 100 h migratory flight of bar-tailed godwits (Limosa lapponica) from Alaska New Zealand across Pacific ocean. In this review we demonstrate that it is ability birds extensively store and use lipids main energy source allows them fast for long periods breeding, moulting, despite their high metabolic rates. Long-term derive largest part required (up about 95%) fat only a minimum amount protein. contrast mammalian running, maintain such proportion derived also endurance flight. This achieved by physiological adaptations preparation, well catabolism fatty acids flight, extensive lipid storage specific upgrading transport system muscles oxidative capacity. Only little known hormonal regulation metabolism related possible actions glucocorticoid hormone corticosterone. There are number trade-offs between competing processes (e.g. maximum oxygen fuel transport) likely linked migration strategy bird.