That day I saw an American robin flew to sit on a branch. I realized this was a baby robin when I saw its parent was feeding it. I took out my camera and was quietly filming about an hour. The baby saw me but it had to stay there to wait for its parent. This gave me the golden opportunity to film the amazing scene. And I googled robin and learned a lot of this bird. This baby must be two weeks old and is a fledgling just left the nest.
Baby robins are ready to leave the nest when they are about 13 days old. Leaving the nest is called fledging. This is a dangerous time for baby robins. Once babies fledge, both parents still feed them for a few days. Baby robins can't fly well when they leave the nest. They must build up muscles and grow adult feathers to be strong fliers. The babies are capable fliers just 10-15 days after fledging. Mom soon leaves to lay a new clutch of eggs. The fledglings will need to learn from other robins when Dad leaves to help with new nestlings. So I could not tell whether it was the mother or father feeding this baby.
After Mon laid the eggs, the first baby hatches 12-14 days. Hatching can take all day. Each chick must fight its way out of the egg. First it breaks a hole in the shell with its egg tooth, a hook on its beak. Then the baby pokes, stretches, and struggles inside the egg, with many stops to rest. Finally it breaks free.
A newly-hatched robins weigh about 5.5 grams, a little less than a quarter. Baby robin skin is clear enough to allow us to see some of the internal organs. Three things a baby robin know as soon as it hatches；to sit very still when its parents are away, to pop up and open its mouth to beg for food the moment its parents return, and to poop as soon as it swallows some food. Baby robins produce their poop in fecal sacs, encased in strong membranes. They don't leak, so the nest is clean. Baby robins are helpless at birth but grow fast! They reach the size of their parents after just two weeks!
When they first hatch, they probably don't recognize their parents! They know the parents have arrived with food by the "bounce" they feel on the nest, and on a sunny day by their parents' shadow. Little by little, they start learning the sounds of their parents. By the time their eyes open, they already know their parents' voices.
Robins identify their babies by sight and sound, not by smell.
For the first four days of a nestling's life, the parent birds regurgitate partly digested food into each baby's mouth . By five days of age, the nestlings get earthworms that parents break into small mouthfuls. Soon parents give them whole worms and large insects, and worms are not even their main food! Both parents have full-time jobs. They protect the nest, find food, and feed hungry babies. A robin might make 100 feeding visits to its nest each day. So you can see robins are very responsible and busy birds.
It started raining. It rained hard on me and the bird. I had to say goodbye to the baby.
