Hummingbirds will tipically follow the same migratoy route year after year. How does a young hummingbird that has just hatched learn the migratory route to take? The answer will probably surprise you.
The newly hatched young have no memory of past migrations on which to rely. They do have the urge to put on a great deal of weight, to fly in a particular direction for a certain amout of time and the urge to look for a place to spend the winter. Once the hummingbird has learned the route the hummingbird will likely trace that same route each year of its life.
What triggers the urge to migrate in these birds? The urrge to migrate is triggered by a change in the length of the day or photoperiod. It has nothing to do with what the temperature is or the amount of food that is available. It may surprise you to discover that hummingbirds will migrate south when the amount of food available is at its greatest abundance.