are Big Babies
A baby robin
leaves the nest when it’s only 13 days old, a hummingbird at 21
days, and an eagle at 70-84 days. Why do you suppose young eagles take
so long to grow up compared to hummingbirds and robins?
1) Robins and hummingbirds are much smaller, with a much shorter life-span,
than eagles. Smaller birds start nesting when they are one or at most two years
old, so many more of their behaviors must be "innate"-that is, instinctive.
That means they don't have to spend as much time learning new things as eagles
2) Hummingbirds take nectar from flowers. Robins search for worms on the ground
and berries in trees and shrubs. Their techniques for slurping up nectar, pulling
out worms or plucking berries are fairly simple and straightforward. Hunting
for live and wary creatures is much trickier--a trout can wiggle away a lot
easier than a berry can! So hunting birds must be very adaptable and intelligent,
and they need time to develop their skills.