Bulletin #7152, Understanding Ruby-Throated Hummingbirds and Enhancing Their Habitat in Maine (PDF) Developed by Nancy Coverstone, Extension educator, Lois Berg Stack, Extension ornamental horticulture specialist, and Jack Witham, associate scientist, University of Maine Holt Research Forest. Special thanks to Mahmoud El-Begearmi, Extension professor, nutrition and food safety, for his assistance on maintenance and sanitation of