Instead you can enjoy hosting your young hummingbird family. If you are fortunate to see this, there is no need for any rescue. Sometimes, she watches them from a nearby branch. After three weeks, the young birds are ready to leave the nest forever.Have grown real feathers and their beaks (depending on the species) are They start to look more like small adult hummingbirds. Even so, it takes at least 9 daysīefore they can regulate their own body heat. In about a week or so the growing chicks willīe covered with fuzzy new feathers.