I decided to set up a bird feeder a few years back because there was just so much snow that year that I felt bad for the little creatures.
Although I originally thought I’d just feed the birds until the snow melted, I ended up feeding the birds all year. One of the rewards of feeding the birds in the summer is getting to watch the parent birds feed their young at the bird feeder. By the time that the young birds can fly around after their parents they are just about the same size as mom or dad. But the juvenile birds engage in the same begging behavior that they did in the nest. To let mom or dad know that they are hungry, the youngsters chirp and flutter their wings. When the parent shows up with food, the youngster typically scoots down low to be in a better position to receive the food.
In the case of seed-eating birds like the goldfinches in the video, the parent cracks the hull of each seed, spits the hull out, and stores the hulled seed in its crop. The crop is a sack-like structure at the end of the esophagus that is designed for storing (not digesting) food. The crop is located at the base of the throat, before the stomach. Toward the end of the video you can see the mother pushing the hulled seeds up from her crop into her mouth so she can deliver them into the mouth of her baby.
I can tell that the parent in the video is a female, not a male, because the males have cute, little black caps as seen below.
You might have noticed that the male bird above seems a much brighter yellow than the female in the video. The female is a brighter yellow in the summer. During their breeding season the bright yellow helps to communicate their good health to a prospective mate. However once their breeding season is over, the feathers of both genders turn a dull brown to help hide them from predators.