The importance of changing climatic variability for tropical wildlife population growth rates

Abstract

Much interest in the population impact of climate change has focused on the widespread increases in mean temperature, but little attention has been paid to the less homogeneous and less predictable changes in temperature variability. Well-established demographic theories have long pointed to a potential impact of environmental variability on population growth rates, but these have rarely been tested in practice, and the limited evidence available has suggested only minor effects. Using long-term data on tropical bird populations, we demonstrate that the prevailing levels of temperature variability are large enough to have a major impact; reducing population growth rates by up to half ...