Bird of Prey Facts – What Makes a Raptor, a Raptor?

Sharp shinned Hawk in my backyard
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)
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)
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)
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)
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.

Bald Eagle

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)
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.

7 comments

  1. Some pretty good info although not completely accurate, one thing I will point out is the plumage. There are numbers of brightly colored raptors, namely Aplomado falcon, Tiercel Kestrral falcon, Orange brested falcon and bat falcon to name a few and many more.

    • Hi, Tim
      Are you referring to raptors that live on the east coast of North America? Because those are the birds I am focusing on. I don’t know the Orange brested falcon or bat falcon. Are those real birds? Or are you pulling my leg? 🙂

  2. This is very interesting, Donna, especially the information about raptor eyelids. You know, that old movie & TV trick of using a red-tailed hawk call with footage of eagles used to confuse me. I’m glad you mentioned it. Finally, I’m happy to have had a bald eagle pointed out to me at the Rose Tree Park hawk watch in Media, Pa a few weeks ago. Apparently they’re common over the nearby reservoir, but I hadn’t noticed them before. You’re right, lots of magnificence around us!

    • Hi, Scott

      I never did get to see the nesting Eagle pair at Tinicum but I did see several last winter.

      Have you ever been to Conwingo Dam on the Pennsylvania-Maryland? The place is crawling with Bald Eagles in December. They fish on the Susquehanna river.

      Here is a link to some photos I took in December 2010.

      Conwingo Dam info

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