What's wrong with the gray bird's buttocks sticky shit

The gray bird's butt shit is because it is thin.It mainly eats grass, fruits, etc., but it will eat crops such as rice, corn, etc. in the maturity of the grain, and the breeding period will prey in insects and small vertebrates.This bird is usually kept in the breeding box. The food must be mixed with mules, millet and mule, and adds a little hibiscus powder, and regularly supplements green vegetables and minerals, so as to ensure the balance of nutrition.