Rates of Primary-Feather Growth in Nestling Birds

Rates of primary-feather growth with respect to increase in length and increase in feather mass were estimated for nestlings of a range of bird species. The relationships between primary feather growth-rate constants and adult primary-feather length, primary-feather mass and adult body mass for these species are described. As adult body size increases, flight-feather growth is completed in a shorter proportion of the post-hatching growth period. The rate of deposition of primary-feather mass scales to final (asymptotic) primary-feather mass with a similar scaling exponent as that relating rates of overall growth in body mass to adult weight.