Developed by ornithologists using only high-quality ingredients, this Songbird Selections Colorful Bird seed blend from Scotts has been field-tested and proven to attract up to 2 times more colorful birds. As an added bonus, it attracts up to 70 percent fewer aggressive Blackbirds, Cowbirds, and Grackles, known to take over feeders and intimidate other birds . It's based on the applied science of feeding behavior and bird vision (birds actually find and choose food based on sight rather than taste ), and tested with over 30,000 feeder observations. Surefresh resealable package with Easy Pour Spout is convenient and easy to use. Rich in highest quality ingredients that birds love.