The American Robin (知更鸟)
The American robin is 8 to 11 inches in length and 12 to 16 inches in width when its wings are spread. The male American robins have dark gray or brown back and wing feathers and reddish－orange chest feathers. The females have the same pattern, but they are a little duller in color.
The American robins can be found in all of the United States and Canada except for Hawaii and the northernmost parts of Alaska and Canada. They can also be found in parts of Mexico and Central America. The American robins are migratory and populations move south in winter, although some populations stay in place.
Robins mate (交配) in the spring from April through to July. A female robin may breed two or three times a season. A female robin builds a cup－shaped nest with soft tree branches, grass and feathers. She spreads mud on the inside of the nest with her breast. After she lines the nest with the mud, she will add grass and other soft materials. Sometimes a male robin helps to collect materials for the nest. The nest is built five to fifteen feet above the ground in a tree or bush. Sometimes a robin builds its nest on a window ledge. A female robin will lay three to five eggs at a time and it will take about two weeks before the baby robins are born