Mysterious Grosbeaks

(Delmar, NY)

We have had rose breasted grosbeaks in past years but not this year. After I researched their feeding preferences my husband put out a platform feeder and used black oil sunflower seeds to attract them. Bingo! Within three hours we had at least three males and two females. They continued to return to our feeder all of June until early July and then suddenly they all left. We did not change anything and are wondering what prompted their sudden departure. Any ideas about how to get them back would be most appreciated.

Comment
I suspect they were migrating and have headed further north, where they have nested in previous years. Lucky Canada!
Susan