Young hummingbirds don't take long before they develop the courage to fiercely interact with the adults. They need to learn quickly, and develop skills necessary to fight and defend territory. Since hummingbirds typically only have 2 young at a time, their population doesn't multiply as quickly as other birds, but since they also develop skills much quicker than other birds, they have a bit less to worry about in being captured by predators.
Within one week of leaving the nest, juvenile hummingbirds develop unbelievable speed and agility, being able to compete with the best of them. They are picked on by the adults soon after leaving the nest, and what seems like cruel behavior, soon reveals the real intentions as the young quickly learn to defend themselves. Tough love couldn't be displayed in any species better than in hummingbirds.
This young Ruby-throat was part of a joint effort with another young Ruby. One juvie showed up and was immediately chased into the sky, through the trees, and around the county. While this was happening, this youngster showed up at the feeder directly above where it's perched. It guzzled up as much nectar as possible and then perched below in a well camouflaged spot, under a canopy of leaves on a very unsuspecting perch. The dominant male of this particular feeder returned, but had no idea of the trouble maker only five feet below him.
Juvenile Ruby-throat hummingbird. August 9, 2019. N.E. of Edmonton, Alberta, Canada.