Energetic limits: Defining the bounds and trade-offs of successful energy management in a capital breeder

摘要: Judicious management of energy can be invaluable for animal survival and reproductive success. Capital breeding mammals typically transfer to their young at extremely high rates while undergoing prolonged fasting, making lactation a tremendously demanding period. Effective the competing demands mother's needs those her offspring is presumably fundamental maximizing lifetime success. How does mother maximize chances successfully rearing pup, by ensuring that both pup herself have sufficient during this ‘energetic fast’? While models were first discussed in 1990s, application analytical technique still very much its infancy. Recent work suggests broad range species exhibits ‘energy compensation’; periods when they expend more on activity, bodies partially compensate reducing background (basal) metabolic rate as an adaptation limit overall expenditure. However, value understanding ecology presently unclear. We investigate whether provide insights into strategy phocid seals. Not only do we expect lactating seals display compensation because but anticipate mothers exhibiting lack are less likely rear successfully. On Isle May Scotland, collected heart data proxy expenditure 52 known individual grey seal (Halichoerus grypus) mothers, repeatedly across 3 years breeding. We evidence exhibit downregulating daily other costs relatively high. individuals fail period end earlier than expected. Our study demonstrate importance animal's Moreover, our multi‐seasonal indicate environmental stressors may reduce capacity some follow strategy.