does this only mean that the Hummingbird is perfect in creation and needs no change to survive?
Hummingbirds were not created, they evolved.
Ancestors of a modern species need not be that morphologically different from their progeny, even over a time span of millions of years. And organism will fill a niche based on its fitness to survive in the niche.
If there are strong selective pressures in the environment to maintain the traits that we see today, even over a 20 million year time horizon, those traits will be preserved. That means that any variation that may have occurred, that does not confer a survival or a reproductive advantage, will be lost to the traits that are selected for.
You then also have the idea of coevolution. If a particular flower that produces nectar that the hummingbirds relied on as their only source of food, could only be pollenated by the hummingbirds, then they would also rely on the hummingbirds. The success of each organism relied upon the success of the other. So the adaptation that made the hummingbird successful at feeding from that plant also made the plant a better breeder, so as both succeeded, but both relied on specific traits of the other, then they both put pressure on each other to stay relatively the same.
Add to that, if the niche was such that the hummingbirds didn't have a significant threat from predators and the plant didn't have parasites or other invasive species that would kill it off, and no other plants in that niche evolved as a food source for the hummingbirds, then there really is very little selective pressure for change, and the traits of both can be maintained for long periods of time.