Developmental tradeoffs during poor rearing conditions in a seabird


Meeting Abstract

90-6  Saturday, Jan. 7 11:30 – 11:45  Developmental tradeoffs during poor rearing conditions in a seabird MANESS, TJ*; ANDERSON, DJ; Louisiana Tech University; Wake Forest University tmaness@latech.edu

Some species reach a smaller size under poor food conditions during early development, whereas in other species final size is not affected. This discrepancy may reflect variation in the importance of structural size in obtaining resources later in life. An offspring with limited energetic resources may face developmental tradeoffs, and rather than reducing overall growth uniformly, resources could be directed toward growth of vital systems or structures or growth could be slowed or reduced in some areas and not others. Seabirds may be expected to prioritize growth of flight feathers since newly independent seabirds must learn to locate temporally and spatially variable food sources over vast areas, often using difficult and complex foraging methods. We examined growth of 2631 offspring that reached the fledgling stage from seven annual cohorts of a seabird, the Nazca booby (Sula granti). We found that nestling growth was compromised under poor rearing conditions: growth rate was slower, overall body mass fell, and growth of some, but not all, structures was reduced. In particular, culmen length was reduced, while wing length was not. This result is supported by the fact that wing length, but not culmen length, is positively associated with juvenile survival in this species.

the Society for
Integrative &
Comparative
Biology