Ontogeny of sex differences in the energetics and kinematics of terrestrial locomotion in leghorn chickens (Gallus gallus domesticus)

• DOI: 10.1038/srep24292
• Publication Date: 2016-04-12T10:08:44Z
• Authors: K. A. Rose; K. T. Bates; R. L. Nudds; J. R. Codd
• Keywords: Sexual maturity; Terrestrial locomotion

Abstract Sex differences in locomotor performance may precede the onset of sexual maturity and/or arise concomitantly with secondary sex characteristics. Here, we present first study to quantify terrestrial morphology, energetics and kinematics a species, either side maturation. In domestic leghorn chickens ( Gallus gallus domesticus ) maturation brings about permanent female gravidity increased male hind limb muscle mass. We found that sexes juvenile cohort leghorns shared similar maximum sustainable speeds, while sexually mature speeds were greater by 67% (males) 34% (females). Furthermore, relative juveniles same sex, absolute duration leg swing was longer males shorter females. Consequently, proportion stride each contact ground (duty factor) higher females compared males. Modulation duty factor development characteristics act minimize mechanical work males; minimise power peak force A incremental response mass-specific metabolic speed common both age cohorts and, therefore, likely results from physiological dimorphisms