When do the hummingbirds leave to go south?
At the start of fall migration, it is generally thought that hummingbirds sense changes in daylight duration, and declining numbers of flowers, nectar and insects. Instinct, their internal biological calendar, and cooling weather conditions also play a role in making the decision to migrate.
Join Alexa Answers
Help make Alexa smarter and share your knowledge with the worldLEARN MORE