First, What Are These Crusts And How Are they Formed In The Feet Of The Bird?
![the feet of the bird](https://i0.wp.com/ipetbird.com/wp-content/uploads/2023/08/the-feet-of-the-bird.jpg?fit=370%2C370&ssl=1)
The crusts are a decomposition of the outer layer of the skin of the goldfinch’s foot . The reason for this decomposition is due to the fungus that grows on its foot. This impedes the access of blood circulation to the…