|Accipiter badius, India|
A hawk is a common term for a medium to large-sized birds of prey. Its usage varies in different places.
- The subfamily Accipitrinae, the subfamily of the Accipitridae often called the "true" hawks. It includes all members of Accipiter and the closely related genera. Goshawks and sparrowhawks are examples. They are mainly woodland birds with long tails and good sight, hunting by sudden dashes from a concealed perch.
- More generally, the term may be used for eagles, kites, and buzzards.
Accipitrine hawks generally take birds as their primary prey. They have also been called "hen-hawks", or "wood-hawks" because of their woodland habitat. Within the hawk species, the female is generally larger than the male. Like most birds, the hawk migrates in the autumn and the spring.
Eyesight[change | change source]
Hawks, like most vertebrates, have four types of colour receptors in the eye. They can see not only the visible range, but also the ultraviolet part of the spectrum. Other adaptations let them detect polarised light and magnetic fields.
They have many photoreceptors in their retina, and an exceptional number of nerves connecting the receptors to the brain. There is an indented fovea, which magnifies the central portion of the visual field. Hawks have always been known to have sharp vision and to be very able hunters.
References[change | change source]
- ↑ "Hawks". beautyofbirds.com. Retrieved 2010-01-30.
- ↑ Kirschbaum, Kari. "Family Accipitridae". AnimalDiversity Web. University of Michigan Museum of Zoology. Retrieved 2010-01-30.
- ↑ "Red-Tailed Hawk". National Geographic. 11 November 2010. Retrieved 18 October 2012.