Predators also feed on young birds, another sector of the bird population with a high mortality rate. A single pair of American Robins, raising only two broods of four young each year along with their reproducing descendants over 10 years can produce about 19 million robins. The enormous overpopulation of the species as a whole from such an increase would prove detrimental to the both the environment and crop development. We can suggest a few preventive measures. Eliminate any possible hiding places around feeders so that birds can easily see cats in the area.
Place birdbaths off the ground and away from shrubbery where cats can hide.
There are several species of hawks that have evolved to prey on small birds. The most common species are the Sharp-shinned Hawk and the Cooper's Hawk. Hawks are protected by state and federal law. The best thing you can do is provide your backyard birds with a lot of places to seek safety if a hawk appears. Dense shrubbery with weak limbs, that cats and squirrels are unable to climb, is another haven.