Allocation of growth in food-stressed Atlantic Puffin chicks

Abstract

In long-lived seabirds that lay a single-egg clutch, allocation of growth to certain body parts may be advantageous for the chick if food is limited. To investigate this, 40 Atlantic Puffin (Fratercula arctica) hatchlings were distributed in seven groups that were raised on different amounts of food to 38 days of age. When food intake was reduced, growth rates were depressed for all characters measured (i.e. body mass and length of the wing, 2nd primary, forearm, head + bill, culmen, skull, tarsus, and middle toe). Head and wing parts grew preferentially relative to the other characters, and onset of growth was delayed in the primaries. All chicks accumulated significant amounts of subcutaneous fat, whereas internal fat deposits were present only in the chicks that received the most food.