Why do blackbirds often close their feathers tightly in hot summers, but loosen them in cold weather?

The feathers of the thrush, like the feathers of other birds, can not only protect against rain, wind, dust and sand, help fly and keep warm, but also play a role in regulating body temperature.

Because thrushes do not have sweat glands, they always open their mouths and breathe harder in hot weather. At the same time, the feathers are tightly closed, which can reduce the gaps between the feathers and allow body heat to be easily discharged. In severe cold weather, the puffiness of feathers causes more gaps between feathers, which act like soft cotton batting to insulate.

However, whether the weather is too hot or too cold, it is not good for the thrush. Measures should be taken to keep the bird at normal temperatures.