Peter et al~
Yup, those Brant are right on schedule. They are the last waterfowl to leave Long Island - because they are headed way up north.
Brant are Arctic breeders and nest as far north as any species of bird. As a result, they cannot arrive on their nesting grounds until last winter's ice and snow are gone. They nest in early June on numerous large islands in the eastern Arctic.
All the best,
SJS