The Cooper's hawk breeds mainly in the United States, southern Canada and northern Mexico. This species was named in 1828 by Charles Bonaparte in honor of his friend and colleague William C. Cooper. They are migratory birds that focus heavily on thermal air for direction. The female Cooper's hawk is a third larger than the males and this species is a great example of dimorphism. They are among the most inversely size dimorphic of any falcon in the world. They breed in forests and dense woods. They are also noted to live in suburban and urban habitats. They consume prey of different sizes, including birds and mammals such as doves, robins, chipmunks, chipmunks and various rodents. In the mid-1990s, the eastern population of the birds declined significantly. Some of the main causes of this population decline include trapping, pesticide contamination, pollution, and shootings. Therefore, the species is marked as a threatened or endangered species in some eastern states. Even though their populations were low, recovery is slowing in many areas. Over the years, this species has been studied intensively by ornithologists and they have collaborated to document the species' habitat and other characteristics. The Cooper's hawk is medium sized and has rounded wings with a long, rounded tail. Males measure approximately 39 cm and females approximately 45 cm. Younger birds have yellow legs and adult birds have orange or red legs. Males have brighter colors than females. Adult birds have a dark blue-grey crown that contrasts with the lighter colored nape. The tails have four alternating straight bands, dark brown and light brown in adults. The tip of the tail may sometimes appear white. Some of the areas where the population of Cooper......middle of paper......voice itching changes with the age of the bird. The best known and most identified call is the cak-cak-cak or “alarm call”. The kik is the most common call of the male, which communicates his presence in the area. The females whaaa and the young birds chirp. Cooper's hawk occasionally runs or walks on the ground, most of the time it rests in trees or flies. The bird sleeps standing on one leg, with its head tucked between its back feathers. Birds maintain their health and feathers by preening, stretching, bathing in water, and scratching their heads with their toes. They lay eggs after breeding, take care of them and protect their chicks. Overall, the birds are adaptable to the human lifestyle and the population is starting to grow slowly. They are very interesting birds and maintain high adaptive characteristics to survive in today's changing global conditions.