Sharp shinned Hawk in my backyard

One winter day, I watched a Sharp-Shinned Hawk unsuccessfully try to catch one of the sparrows and house finches at my bird feeders. I was fascinated by how the birds quieted down and flew off in many directions before the hawk even reached the feeder. That  is how I could tell a predator was around, by the reaction of the birds.

If you think about it, raptors aren’t the only “birds of prey”.  Swallows, warblers and chimney swifts are among other birds that catch, eat or feed insects to their young. But a few characteristics make birds of prey different.

The common name “raptor” comes from the Latin words “robber” and “seize”. Raptors bodies are adapted for seizing prey.

These swift fliers eat and hunt animals such as small birds, mice, rats, snakes, lizards, frogs and fish.

Peregrine Falcon (Falco peregrinus)

All raptors have a strong, compact body, heads that are generally round, a short sharp-hooked beak, strong feet with sharp talons, keen eyesight, and a carnivorous diet.

There are two kinds of raptors diurnal or day-fliers which include hawks, falcons, vultures, ospreys and eagles. Nocturnal raptors include the owls.

Red-tailed Hawk (Buteo jamaicensis)

Raptors have forward directed eyes and sharp vision to spot prey from a distance.

Raptors have three eyelids! They have a top and bottom eyelid plus a third, transparent eyelid which closes laterally across the eye. This special eyelid is called a nictitating membrane and is used to:

• keep the eyes moist,
• protect the eyes during flight, and
• protect the eyes when feeding themselves or their young.

When humans close their eyes to blink or sleep the upper eyelid closes. Depending on the species, raptors may close the top eyelid, the bottom eyelid, or both. 

An additional form of eye protection in many raptors is a bony shield, called the superciliary ridge, that projects above the eye. This ridge acts like a visor for protection from the sun and also protects the eyes from injury while hunting. It also gives raptors a menacing appearance. 

Broad-wing hawk foot (deceased, window collision)

Raptors have short legs and long toes with bent sharp claws.The feet and beaks are designed for catching and ripping open the skin of prey.

Raptors range in size from the Elf Owl which is smaller than a Robin, to the largest bird in North American, the California Condor. In almost all raptor species, females are larger than males.

Northern Harrier (Circus cyaneus)

Raptors colors are subdued with plummages of tans, grays, and browns. None of the raptors are brightly colored. In most species adult and immature juvenile plumages are very difficult to tell apart. This can make identification a real challenge.

Raptors make simple calls. Usually the calls consist of high pitched and harsh repeated notes. They don’t sing. Kites and buzzards tend to be the most vocal.

In one of the bird watching workshops I attended, I learned that the high-pitched call of eagles in television commercials are not actually eagles but the Red-tailed hawk. The squeaky calls of eagles aren’t dramatic enough.

Raptors can live a long time. Bald Eagles can live over twenty years. Smaller raptors like kestrels can live up to ten years. Once a bird reaches adulthood, it will probably live a long time as long as habitats and food supplies are relatively healthy and abundant.

Raptors are found on every continent except Antarctica. The greatest number of species is found in the tropical rainforests of Central and South America.  Raptors live in urban, suburban and rural areas. The Sharp-shinned Hawk, I wrote about earlier, lives in my neighborhood on the edge of large, very urban, Philadelphia. It flew right into my small backyard.

Bald Eagle (Haliaeetus leucocephalus)

It just proves you don’t have to go to distance lands to see something magnificent.

Information in italics from, ” General Raptor Facts”, Bureau of Land Management, http://www.blm.gov/id/st/en/prog/blm_special_areas/birds_of_prey_nca/links/general_raptor_facts.html, accessed 22 November 2011.

Red-tailed Hawk (Buteo jamaicensis)

Last weekend I watched two young Red-tailed Hawks flying in circles above a dense suburban neighborhood.

I could tell they were Red-tails by the relative large size, white belly with streaked belly band ( a juvenile trait), the sound of the distinct call and the position of the wings in flight.

I was very proud my skills had grown so much. I watch these birds all time, they are so common in the Philadelphia area. I can tell a Turkey Vulture and a Red-tailed Hawk at a glance, now. I couldn’t before.

I never tire of seeing a Turkey vulture or a Red-tailed Hawk soar for a long time. The birds are usually a speck in the sky before I stopping watching. The gracefulness and elegance of seeing them ride the thermals fascinates me. Thermals are rising columns of sun-heated air that rise from the ground.

Birds of prey are hunters of the sky. They are commonly known as, raptors. Their powerful sharp beaks and claws, seize prey. One of many nice things about these fliers is that they hunt by day and are easily seen.

As a general rule birds of prey  are more active in the early morning and early evening. Soaring eagles and hawks need the rising warm air currents (thermals) to soar and will be more active after the sun is up a few hours and the sun has warmed the ground.

Spring and fall are great times to see raptors. At these times many raptors are migrating to more abundant food sources. Many raptors use well-defined flyways to get from place to place. These are hotspots along mountains and coastlines where migrating raptors and other birds converge or fly over. Stationing yourself at one of these locations often means you can see hundreds of migrating birds of many different species in one day.

Although you can see raptors year around, another good time to see raptors is during the nesting season. The nesting season runs from mid-March through June, depending on location. From mid-May through June young birds are fledgling and learning to fly.

Bald Eagle (Haliaeetus leucocephalus)

When you are outdoors, keep your eyes open. Many people will miss many birds simply because they are not looking for them.  A motionless Red-tailed Hawk sitting on the cross arm of a power pole is easy to miss. I often see hawks as I drive along the turnpike in the countryside of Pennsylvania.  They perch in roadside trees, searching for prey in the grass and highway median.  By looking up you might see a small dark objects in the sky which might be an eagle or hawk soaring above you.

Some things that might actually be a raptor include:

• a fence post that is extra tall
• and extra insulator a power or phone pole
• a rock outcrop with a prominent “point” at the top
• a bird sitting on the wire between poles (possible an American Kestrel)
• in winter, a dark object in a leafless tree

Many people can watch soaring birds for hours on end and marvel at the beauty and elegance of their abilities without ever worrying about exactly what type of raptor they have been admiring. Then there are those who like the challenge of identifying the birds they are seeing. The plumages of raptors differ within a species according to age. Juveniles can look very different from adults. And adults of the same species might have slightly or very different coloration depending on what area they are from.

There are many field guides to Hawks and other birds of prey. I would suggest spending time looking at field guides in your local library or bookstore.

Northern Harrier (Circus cyaneus)

When you are using your field guide remember this important quote from Roger Tory Peterson: “Birds have wings and like to use them”. This means you should watch the bird for as long as possible, taking note of different features before you consult your field guide. If you instantly start looking through your guide when your first see a bird, you may narrow your choices down to three or five birds, and then when you look back through your binoculars to check specific features, the bird is gone.

So, when you are looking at an unknown bird start at the head and work your way to the tail, making note of specific features that you see. Once the bird is gone then consult your field guide.

This week, In Season, will focus on observing birds of prey with several informative posts.