The Sibley-Munroe checklist was a landmark document in the study of birds. It drew on extensive DNA-DNA hybridisation studies to reassess the relationships between modern birds.
... to 44, 21.9% from 45 to 64, and 16.9% who are 65 years of age or older. The median age is 39 years. For every 100 females there are 113.3 males. For every 100 females ...