The years it takes for birds to mature from young bird to adult bird vary from species, and generally the larger the body, the longer it takes.
In the case of a small seagull species, the theory is two years.
The chicks born in the breeding ground in summer are wrapped in cotton wool, but it is said that they will soon have the same shape as adult bird, a brownish young feather.
Young feathers, 1st winter feathers, 1st summer feathers, and 2nd winter feathers gradually shift from brownish young feathers to gray adult bird feathers, but the progression varies between individuals. Seems to be seen.
adult bird also repeats summer feathers and winter feathers.
In young bird, the beak and legs are yellowish, but the yellow gradually becomes darker and orange, and in adult bird it becomes red.
The difference between young bird and adult bird is well understood.
According to the calendar, although it is approaching spring, the cold weather is still severe, and the lovely expression of the Japanese gull who relax in the sun pool along the banks of the Sumida River feels warm.
