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Tags: flight. All are classified as birds of prey, or raptors. Sixteen species that regularly occur in New Jersey are described on this website. Although all hawks have certain basic similarities such as keen eyesight, hooked beaks and taloned feet, a wide diversity of forms and sizes exists among them.
For instance, an American Kestrel weighs only 4 ounces, while a Bald Eagle can weigh 13 pounds — 52 times as much.
Hawks are efficient predators. They catch, kill, and eat a wide variety of other animals in order to survive. This predation is not mean or cruel. Hawks are strong, powerful birds. Their feet are equipped with sharp, curved talons for capturing prey, and their strong beaks are hooked for biting and tearing flesh.
Swift fliers, some hawks can attain speeds of over mph when diving. Some species undertake long migrational journeys, traveling thousands of miles each year — a testimony to their strength and stamina. Their sense of hearing is excellent, and their eyesight the best in the entire animal world.
Not only can hawks see greater distances than humans, but their visual acuity the ability to see clearly is eight times that of ours. Hawks also see in color. In many animal species the males are larger and stronger, but in hawks the difference in size between the sexes is reversed, and females are larger. This sexual size difference is often appreciable. In some species, such as Sharp-shinned Hawks, females can weigh twice as much as males.
Here in the northeast, hawks typically breed in the late spring or early summer. Most hawks pair for life, but if one partner dies, the other will quickly find a new mate. Some pairs remain together year round; others may separate after the breeding season. The allegiance to the breeding site is strong, however, and even those that migrate or disperse will usually return to the same nesting territory and the same mate each year.
Large hawks lay only one or two eggs each year, small hawks from three to five. Incubation takes three to six weeks, depending on the species.
Small hawks, like Kestrels and Sharp-shinned, grow to full size in one month; large species, like eagles, are full grown in only 11 weeks. The young leave the nest fledge at this time, but often remain with their parents for several more weeks before attaining total independence. All hawks are protected by state and federal laws. It is illegal to capture or kill a hawk, or to possess a hawk, alive or dead, without the proper permits from both the State of New Jersey and the U.
Fish and Wildlife Service. Because they are predators, hawks have historically been regarded by many people as vermin. In the past, they were seen as wanton killers — cruel and harmful creatures. Fortunately, with our increased ecological knowledge we now realize that hawks are neither harmful nor cruel.
They are, like all living things, important parts of a diverse and intricate natural world. The protection of that natural world is of paramount importance to their well-being, and to ours. Accipiters are hawks that inhabit deeply wooded areas. They have short rounded wings and long rudder-like tails which allow them to maneuver among the trees.
Their recognizable flight pattern consists of several rapid flaps and then a glide. As a group accipiters are secretive and are observed less frequently than most other hawks. Sharp-shinned Hawks are the smallest of the three North American accipiters. They measure 10 to 14 inches long and have wingspans of about 2 feet, yet weigh only 2 to 7 ounces.
Young Sharp-shins are brown backed and have brown streaks on their white breasts. As they mature, the colors change: their backs become slate-gray, and their breasts become barred with reddish-brown. Even their eye color changes with age — from yellow to deep red. The small head is round, and the long, square-tipped tail has narrow black and gray bands.
They are swift, agile hawks well adapted to flying in heavily forested areas. Their prey, predominantly small birds, is captured in dashing, headlong pursuits. In addition to birds, it also captures mammals, including squirrels and rabbits, and occasionally takes lizards and amphibians. The reasons for its decline are not positively known, but habitat loss, nesting failures from the effects of pesticides, and direct persecution by man could be contributing factors.
It is presently classified as a species of special concern in New Jersey. During disputes, the males dive steeply, talons extended, and swoop up and down repeatedly. Red-tailed hawks spend much time hunting, and do so in two different ways: by soaring on thermal updrafts with eyes on the ground and by sitting on tall trees, waiting for prey to come by. They are often seen perching in trees or atop telephone poles, staring at the ground watching for prey.
Sometimes mated pairs of red-tailed hawks attack as a team, cornering their victim. Red-tails eat fish, mice, rats, squirrels, rabbits, large insects and carrion stolen from other raptors. Sometimes they even eat other raptors. These hawks attack and eat smaller birds caught unaware while building nests or hunting for food. When it's cold, red-tailed hawks eat more than they do in warm weather, helping conserve body heat.
Question 4 : What are some kinds of birds that don't tuck their legs in as they fly? They fly with their legs stretched out behind and their neck stretched out ahead, balancing each other so their center of gravity is between their wings where it needs to be for long flights. Their long, wide wings allow them to fly using different kinds of flight techniques. When cranes are flying just a few miles or less, they use typical flapping flight. They usually flap with steady beats until they come in for a landing.
Then they use their legs and wings to slow down and ease their way to the ground. Cranes can bend their legs and draw their feet in to their bodies when it's severely cold during migration, but that's exceptional. See if you can design a crane that can really fly, or at least glide. Use cardboard, paper, paste or glue, paper clips, and any other materials you want to try.
If you want a pattern designed from a real crane silhouette, click on the small pattern to see a larger sized one. Or try to develop your own pattern, from paper airplane designs or anything else that might work.
Test your birds to see which stay aloft the longest, and which fly the farthest. National Science Education Standards. Life Science Each plant or animal has different structures that serve different functions in growth, survival, reproduction. Living systems at all levels of organization demonstrate the complementary nature of structure and function.
Physical Science. The Gravity of the Situation Isaac Newton is the scientist who first realized that gravity is a force between two objects that draws them toward each other. The more mass an object has, the more it pulls other things toward it. The largest object anywhere on earth is the planet itself, so gravity pulls everything down toward the center of the earth. Question 1 : If gravity pulls everything down, why do helium balloons go up?
Bird skeleton: designed for flight Gravity pulls on birds, too. In order to minimize the effects of gravity, birds are adapted to be as light as possible. These are some adaptations that help make birds light: Hollow bones Feathers Babies don't grow and develop inside the mothers' bodies.
They develop in eggs outside their mothers' bodies. Birds eat foods that are very high in usable calories so they get as many calories as possible from from a small amount of food. Seeds, fruits, and meat from prey are the main food items for birds. Virtually no birds except the Hoatzin, which lives in South America eat leaves, which take a long time to digest. Their efficient digestion allows birds to get rid of useless weight very quickly.
Birds don't have bladders. A bird urinates as soon as it has to, getting rid of the useless weight. Heron Flight. An Aerodynamics Primer In order to fly, birds must do four things:. Whooping cranes taking off. Staying up there Once birds get up in the air, they use two main flying techniques to stay up there. Thermal air currents develop in places where the air is warmer in one spot than an adjoining area, such as a paved road alongside a snowy field. Even on a very cold day, the sun will heat the pavement at least a few degrees more than the snow.
This slightly warmer air is slightly lighter than the colder air, and rises.
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