A hummingbird instinctively knows when to migrate. Fewer hours of daylight trigger hormonal changes that cause the urge to fuel up and fly south. Your backyard hummers will leave their breeding grounds, even though nectar-rich flowers are still in bloom and sugar-water feeders are full.
"Males are feeding almost exclusively on nectar feeders. Females are mostly feeding on Black & Blue salvias, Wendy's Wish salvias, red and purple flox, and bee balm. Lots more activity at feeders at this point. Am refreshing nectar more often than past years. Evening roosting time is already noticeably shorter, around 8:35 versus around 9:20 in early July."
Mike Oakdale, MN 08/11/15
Amy Evoniuk
