| Abstract: | While accelerated growth can be advantageous to nestling birds, there may be a tradeoff between rapid growth and resistance to food shortages. Common murres Uria aalg e are colonial seabirds that benefit from reproductive synchrony. Individuals that lay eggs late should benefit if they produce chicks capable of growing quickly and fledging synchronously with their neighbors. In this study, we controlled food provisioning of captive-hatched common murre chicks from a single subcolony and examined differences in growth between early-hatched individuals and their later-hatched neighbors. We assessed potential costs of rapid growth by comparing growth of chicks fed ad libitum with their growth under food restricted conditions. Chicks that hatched later were heavier, ate more and gained body mass more quickly than chicks that hatched earlier. Late-hatched chicks grew quickly enough to reach the same mass as their early-hatched neighbors in five days. However, chicks that grew more quickly under ad libitum food conditions grew more slowly when food was restricted. We conclude that murres that lay eggs late may synchronize their reproduction with early-laying neighbors by producing rapidly growing chicks. However, the ability to compensate for late hatching by growing quickly can be costly when food becomes limited. |
