Wood Thrush (IMAGE) University of Massachusetts Amherst Caption The wood thrush is a declining species that some conservation biologists are concerned about. While one analysis shows a 2 percent per year decline in their numbers, a new model from UMass Amherst suggests this species had about a 7.5 percent decrease in its climate niche breadth over the study period. Credit UMass Amherst/David King 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.