Savannah Sparrow (1 of 2) (IMAGE) Smithsonian Caption The savannah sparrow is one of the several sparrow species that showed a difference in bill size depending on the daily high summer temperatures of their salt marsh breeding habitats. Credit Cephas Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.