Data from: Postnatal growth rates covary weakly with embryonic development rates and do not explain adult mortality probability among songbirds on four continents

Growth and development rates may result from genetic programming of
intrinsic processes that yield correlated rates between life stages. These
intrinsic rates are thought to affect adult mortality probability and
longevity. However, if proximate extrinsic factors (e.g., temperature,
food) influence development rates differently between stages and yield low
covariance between stages, then development rates may not explain adult
mortality probability. We examined these issues based on study of 90
songbird species on four continents to capture the diverse life-history
strategies observed across geographic space. The length of the embryonic
period explained little variation (ca. 13%) in nestling periods and growth
rates among species. This low covariance suggests that the relative
importance of intrinsic and extrinsic influences on growth and development
rates differs between stages. Consequently, nestling period durations and
nestling growth rates were not related to annual adult mortality
probability among diverse songbird species within or among sites. The
absence of a clear effect of faster growth on adult mortality when
examined in an evolutionary framework across species may indicate that
species that evolve faster growth also evolve physiological mechanisms for
ameliorating costs on adult mortality. Instead, adult mortality rates of
species in the wild may be determined more strongly by extrinsic
environmental causes.