Bird Of Prey
Read more: Why Are Birds of Prey Important to Ecology? | eHow.com http://www.ehow.com/info_8164858_birds-prey-important-ecology.html#ixzz24qA6nAID
Read more: Why Are Birds of Prey Important to Ecology? | eHow.com http://www.ehow.com/info_8164858_birds-prey-important-ecology.html#ixzz24qAHrfbW
Birds of Prey are Birds that Haunt food primarily via flight,using Keen senses,especially vision.They are defined as birds that primarily haunt vertebrates,including other birds.their talons and beaks tend to be relatively large,powerful and adaptable for tearing flesh.In most cases,the females are considerably larger than the males.
The term "Raptors"is derived from the Latin word rapere ( Meaning to seize or take by force) and may refer informally to all birds of prey,or specifically to the diurnal group.beacuse of their predatory lifestyle,often at the top of the food chain,they face distinct conservation Concerns.
The term " Bird of Prey " has wide meaning that includes many birds that haunt and feed on animals and also birds that eat very small insects.In Ornithology,and the defination used here,the term has a narrower meaning for birds that have very Good Eyesight for Finding food,Strong feet for holding food , and a strong curved beak for tearing flesh.Most birds of prey also have Strong curved talons ( Claws) for catching or killing Prey.
Why Are Birds of Prey Important to Ecology?
The word "raptor" is a Latin word, meaning "to carry away." This is precisely what birds of prey do; they carry away their prey. People watch in awe as an eagle soars across the sky or a hawk swoops down to catch a field mouse. This group of aerial warriors is made up of owls, hawks, eagles and osprey. Not only are these birds astonishing to watch, they also perform important tasks for our world. Ecology benefits from raptors in more than one way.
Read more: Why Are Birds of Prey Important to Ecology? | eHow.com http://www.ehow.com/info_8164858_birds-prey-important-ecology.html#ixzz24qA6nAID
Balancing Act
Raptors feed at the top of many food chains. Mice, field rats, rabbits, squirrels and other rodents, as well as fish, insects, amphibians and reptiles may have years when their population explodes due to good weather and a surplus of food. This is a common experience with fish, amphibian and even snake populations. Birds of prey help to balance the size of these populations. Scientists monitor raptor populations carefully. An increase in the number of raptors within an ecosystem is an indicator that a species population is too high. High populations of any one species can destroy the delicate balance in an ecosystem.
Ecological Gauge
- Raptors have been called "ecological barometers," which simply means they help us gauge how healthy a habitat is. Birds of prey are extremely sensitive to many environmental changes in an ecosystem. They can even sense chemical and pollutant levels that can give people an early warning of any impending airborne threats. Pesticides and other chemicals can build up in our environment and are passed on to animals. This can lower raptor populations due to birds ingesting prey riddled with toxins, which in turn signals scientists that a possible problem exists.
Farmers' Friends
Since many of the smaller raptors feed on insects and larger ones prey on rodents, many farmers truly appreciate them. The American kestrel, a smaller falcon, and the Eastern screech owl feed on insects. The great horned owl and the red-tailed hawk feed on rodents. Grasshoppers, cutworms, as well as rabbits and field mice are capable of destroying entire fields of crops if left to reproduce freely without any birds of prey to feed on them. Controlling pests through this method is called biological control. If a farmer can control pests by natural predation, he has no need to use pesticides or insecticides, which helps protect the environment.
Disease Management
Some of the larger birds of prey like the turkey vulture feed primarily on carcasses of dead animals. Occasionally, they will prey on weak or sick animals. This feeding habit actually helps the environment by getting rid of diseased animals or their carcasses to prevent further spread of any disease the animal was carrying. The stomach acids of the turkey vulture are so powerful that it is resistant to most bacteria and germs. This is probably why the turkey vulture has been around 40 to 50 million years. Several species of vultures and condors besides the turkey vulture practice feeding on dead animals and making the environment safe for other animals.
Read more: Why Are Birds of Prey Important to Ecology? | eHow.com http://www.ehow.com/info_8164858_birds-prey-important-ecology.html#ixzz24qAHrfbW
| What Makes a Bird a Raptor? HOOKED BEAK
A raptor's beak is one feature used to set them apart from other birds (see Curvy Beaks Activity Sheet). All raptors have the same beak design, curved at the tip with sharp cutting edges to tear apart prey that will easily fit into the mouth.
The beaks have evolved over time based on the type of prey eaten. For example, the American kestrel has a small beak for eating small prey, like mice and insects. Eagles have powerful, heavy beaks for tearing large pieces of meat, but snail kites have a highly specialized long, curved beak for probing inside snail shells.
SHARP TALONS/LEGS AND FEET |
Birds of prey have powerful leg and toe muscles that, when combined with their sharp talons, make their feet lethal weapons (see Sharp Feet Activity Sheet), perfectly designed to catch, hold, and carry prey. The length and size of a raptors toes, and the curvature and thickness of its talons are related to the type of prey it pursues.
 Most birds of prey will have three toes pointing forward and one pointing backward. These toes can apply an extremely powerful grip on their prey, literally crushing it to death. The talons may also be used to pierce a vulnerable spot, such as the back of the neck, to quickly kill the prey. Eagles and hawks kill their prey by dislocating the neck.
Osprey have two toes facing forward and two facing backward. This allows them to hold the fish they catch with four claws, two on each side for a secure grip. Ospreys also have spiny scales on their feet that help them hold the slippery fish more securely.
Owls also have four toes. However, one of the toes is very flexible, and can be rotated forward or backward for a two plus two or a three plus one toe arrangement.
|
EXCELLENT EYESIGHT
Raptor's are believed to have the keenest eyesight in nature because of the size of the eyeball and the eye muscles designed for rapid focus. Diurnal raptors have full color vision and two concentrations of cones (one directed to the side and one directed forward) in each eye, which control color perception.
The sharpest point of vision at these concentrations is called the fovea. When the fovea work in unison, they give raptors accurate depth perception, which is very important for birds of prey that must focus quickly when chasing moving objects.
The keenness of vision is related to the agility, size, and color of prey a raptor hunts. When a bird bobs its head, it is using its eyes like a range finder and focusing in on a specific area.
Nocturnal raptors, the owls, have an added advantage over other raptors with their remarkable sharp night vision. Owls have a concentration of more rods in their eyes that are essential for seeing under low light conditions. An owl's eyes are also located in the front of their heads, much like humans. By contrast, the night vision of diurnal raptors is no better than a humans vision at night. Another thing that sets raptors apart from other birds is a special eyelid or nictitating membrane.
 * NICTITATING MEMBRANE Illustration © Zoobooks Birds of Prey by J. B. Wexo, 1996. Wildlife Education, Ltd., San Diego, CA. Reproduced with permission.
This special transparent eyelid closes laterally across the eye and is used to
When humans close their eyes to blink and sleep the upper eyelid closes. Depending on the species, raptors have eyelids that close from either the bottom or top, for blinking and sleeping. WOW!
An additional form of eye protection in most raptors is a bony shield that projects above the eye. The bony shield adds protection when raptors pursue prey into brush, protects the eyes from injury while hunting, and also gives raptors a menacing appearance.
|
Raptor Nesting Habits
A female raptor is often larger than the male. The reason for this size difference is really unknown, but scientists think that it is because the female lays the eggs and spends a lot of time incubating and protecting the nest.
Nesting habitats of raptors vary. A few examples of what raptors may do to help rear their young include:
For those raptor species that build nests, typically the female constructs while the male provides the material. Many raptors build a new nest each year, while others, particularly large raptors, reuse old nests or alternate between a number of nests.
 EggsRaptor eggs are typically large, rounded or oblong ovals, and vary in color. The number of eggs laid depends on their size. Large raptors lay fewer eggs than smaller raptors. It is believed that larger raptors live longer and need fewer eggs or young to sustain the viability of the species, while the opposite is true for smaller raptors.Raptors have a two to three day lapse between laying each egg, and generally begin incubation after all of the eggs are laid for that nesting season (owls begin incubation immediately after the first egg is laid). The female does the incubating while the male provides food. The period of incubation also varies with the size of a bird. For owls, hawks, and falcons there is usually a 26 to 35 day incubation period, while for eagles and vultures it is 36 to 50 days.
Raptors of temperate climates breed in spring and summer when warmer weather ensures rapid growth and survival of young. Other natural resources also aid in the success of a nesting season . . .
 After an eggshell is first cracked, it usually takes one to two days before hatching is complete. Raptor chicks grow quickly, doubling their birth weight in only a few days. The length of time a raptor spends from hatching until it is ready to fledge depends on size. Larger raptors stay in the nest from two to three months, while smaller raptors stay until they are three to four weeks old.
In temperate areas, like Idaho, raptors must grow rapidly in order to be ready to migrate when the seasons change and become too warm.
|
