Why are hawks eyes glowing

The latest installment of The Outside Story, sponsored by the Wellborn Ecology Fund of the New Hampshire Charitable Foundation, explores local data showing ice-out coming earlier, lilacs blooming sooner and predictions of shorter sugaring seasons. A blue supermoon will rise on January 31 — a rare occurrence indeed. The Outside Story, sponsored by the Wellborn Ecology Fund, explains how black bears 'go to bed fat and strong and wake up skinny and strong'. The Outside Story: Common nighthawks are neither common, nor nocturnal, nor hawks.

But they are really cool. A partial social eclipse will be visible in New England on Monday. The Outside Story explores the mythology and science of these dazzling astronomical events. Phoebes take up residence every summer under awnings and atop porch lights, seemingly unperturbed by our presence. The Outside Story, sponsored by the Wellborn Ecology Fund, offers a primer on the most beautiful song in our northern New England woods.

What kind of woodpecker am I hearing? Turns out, you can tell them apart by the style of their drumming. Load More Stories. Enable Accessibility. Eyeshine in animals. Illustration by Adelaide Tyrol. Related Stories. Chipmunk Game Theory The latest installment of "The Outside Story," sponsored by the Wellborn Ecology Fund of the New Hampshire Charitable Foundation, explains how eastern chipmunks have evolved to be energy maximizers, seeking to strike the optimal balance between energy gain per cheek-pouch load of food and number of trips back to the burrow.

The retina receives the image passed through the eyeball, and reports its stimuli to the brain, by way of the optic nerve No. The human retina has two kinds of receptor cells: cone cells used for daylight vision and; rod cells used for low light levels. And here's the thing with regard to what's seen in daylight:.

The denser the retina's cone cells, the sharper is the perceived image. The human eye has at most , cones per square millimeter, while House Sparrows have approximately twice that number. Hawks, who must spot small prey from the sky, possess about five times as many as humans! Songbirds and predators such as hawks are believed to have the sharpest vision among birds. They can see details at distances two to three times farther away than humans.

So, retinas in human eyes have two types of photoreceptors that "translate" light into nervous impulses to be sent to the brain, rods and cones. Birds have three types of photoreceptor:. This enables birds to see more colors than humans. In fact they may be able to perceive ultraviolet or near-ultraviolet light, which humans cannot.

Unlike many birds with eyes that sit at an angle, owl eyes face directly forward, giving them incredible binocular vision. Their large, tube-shaped eyes contain many more rods than human eyes, which allow them to be more sensitive to light.

Their irises widen to allow more light to reach their retina at night. Because the iris adjusts, owls can also see during the day unlike other nocturnal animals that can only see well at night , but their vision is slightly blurry and they cannot see colors well. Owls and other animals with excellent night vision have a reflective surface behind their retina known as the tapetum lucidum.

Eagles may be able to spot a rabbit from the sky, but mantis shrimp might have the most complex eyes in the entire animal kingdom. For example, humans have three types of cones in our eyes, allowing us to see the colors red through violet. Mantis shrimp, on the other hand, have 16 types of cones. The set-up of their eyes allows the shrimp to move the eyes independent of each other without compromising vision much like a chameleon. They therefore have a wide field of vision, and their color receptors allow them to pick up on small changes in color almost instantaneously.

This can help them find prey and mates, and avoid predators.