According to a study conducted at the Powdermill Nature Reserve in Pennsylvania, female hummingbirds survive at a higher rate then male hummingbirds. The male hummingbirds had an average annual survivorship of 31 percent fcompared to 42 percent for females. The study didn’t offer an explanation as to why the female hummingbirds had the higher rate of survival.
It is difficult for the young fledglings to survive. In fact, up to three-quarters of a given year’s fledglings are likely to die due to numerous causes. These include the following: predators, disease, accident, problems which occur during migration, or other problems.