Meeting Abstract
114.3 Monday, Jan. 7 Wings versus legs: mechanistic underpinnings of variation in locomotor strategies among birds HEERS, A M*; DIAL, K P; University of Montana; University of Montana ashmheers@gmail.com
Among the 10,000 species of living birds and their extinct dinosaurian ancestors, relative musculoskeletal investment in wings versus legs is highly diverse, varying both across species and throughout ontogeny. Such variation likely has profound effects on locomotor performance and many related aspects of bird ecology, including habitat preferences, foraging strategies, migration patterns, and parental care. During aerial locomotion, high leg investment may hinder wing performance. Likewise, high wing investment may hinder leg performance during terrestrial locomotion. Given these potential relationships between body modules, do tradeoffs between wings and legs influence locomotor ontogeny and evolution? To explore this question and better understand the ecological ramifications of how wings and legs function both independently and cooperatively during ontogeny and evolution, we used published and new data to compare wing and leg morphology and locomotor performance (i) across adult birds of different species and (ii) during ontogeny, in three precocial anseriform-galliform species with distinctly different sequences of locomotor development. Our findings suggest that birds with high wing investment may have reduced mass-specific leg performance and rely on wing-dominated locomotor behaviors, while birds with high leg investment may have reduced wing performance and rely on leg-dominated locomotor behaviors. For example, among adults, wing and leg investment are negatively correlated. Similarly, ontogenetic increases in wing investment and performance can compromise leg investment and performance, and vice versa. Collectively, these results provide new insight into the mechanistic underpinnings of variation in locomotor strategies among birds, and suggest that performance tradeoffs between different body modules may be important during ontogeny and evolution.
