Signals of need and quality: Atlantic puffin chicks can beg and boast

Need and hunger models of honest begging predict that lower-quality offspring should call more, or beg, to signal their poor body condition or hunger. In contrast, quality models of begging predict that offspring of higher fitness should call more, or boast, to signal their viability to parents. We observed 2 types of calls in Atlantic puffin (Fratercula arctica) chicks: a shorter peep call and a longer screech call. Poorly fed chicks screeched during a higher proportion of parental visits than well-fed chicks. Food-supplemented chicks showed a decrease in the proportion of food visits with screech calls, whereas control chicks did not. Chicks in good body condition peeped more than chicks in poor body condition and these chicks showed a greater increase in the peep call rate after supplemental feeding than chicks that started off in poorer condition. Screech calls may signal need and/or hunger to parents, whereas peep calls may signal chick quality. This combination of signals should allow parents to make strategic resource-based decisions, allocating more food to hungry or lower-quality chicks when resources are abundant and preferentially feeding high-quality chicks when resources are scarce.