What is smallest bird of prey?

The smallest bird of prey is the elf owl (Micrathene whitneyi), which is found in the southwestern United States and Mexico. This tiny owl measures only about 5 inches long and weighs between 1 and 2 ounces. Despite its small size, the elf owl is a skilled predator, preying on insects, small rodents, and even other birds. The elf owl is also known for its distinctive call, which sounds like a series of high-pitched squeaks.