Do u know that the birds don’t urine ? Yeah, its a real fact about all mammals. The birds excrete that white pasty stuff instead of separately urinating. So  the bird’s don’t exactly urine but they do something like it. The bird have a chamber, where digestive wastes, uric acid, and sperm go before leaving the body. When this uric acid is in that chamber, the birds can absorb some of the water back. It helps them to preserve water.At last the bird’s all waste leaves via the anus.

The bird's don't urine