#local adaptations

North American song sparrows may be more resilient to climate change thanks to a remarkable adaptation: a stunning range of body sizes found throughout the bird's westernmost range. Cornell researchers and their colleagues have done whole genome sequencing of North American song sparrows that has revealed the genetic underpinnings for the range of body sizes. This work is the first result from a larger research effort to sequence song sparrow genomes from across North America, spanning nearly all of the 25 recognized subspecies. The current research published in Nature Communications by scientists from the University of British Columbia, the Cornell Lab of Ornithology, Ouachita Baptist University and the University of Alaska, Fairbanks. The study offers support for what is known as Bergmann's Rule, which states that broadly speaking, among organisms that regulate their own heat, natural selection in colder climates leads to larger-bodied organisms while warmer climates lead to smaller bodies. Larger bodies are more efficient at retaining heat. Smaller bodies allow an organism to stay cooler. Song sparrows that live year-round on Alaska's Aleutian Islands can be up to three times larger than their cousins near San Francisco Bay.