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Our present-day raptors, and all birds, actually share a direct link to those ferocious velociraptors. Scientists believe that birds most likely evolved from the family of dinosaurs known as the Dromaeosaurs around 150 million years ago, the same family that later gave rise to a number of velociraptor species.
These days,
"raptor" is more likely to conjure up an image of a Toronto
basketball player or one of those lithe, cunning dinosaurs of
Jurassic Park fame, than the birds of prey to which this term
more correctly refers. But the real raptors, which collectively
include eagles, hawks, kites, harriers, falcons, the osprey,
owls and, depending on your source of reference, vultures are
every bit as fascinating and worthy of our attention. In fact, a
number of raptors have been grabbing local and national
headlines of late. The now famous red-tailed hawk, Pale Male,
who was evicted from his nest site high atop an upscale New York
City apartment, but then allowed to return, now has
his own web site and is
the subject of an award-winning documentary. The Virginian-Pilot
recently featured a story about the red-tailed hawks that still
call the Virginia Beach Town Center area home, despite all of
its recent development. For the last several springs, many
Richmonders have been thrilled to watch the progress of a pair
of peregrine falcons caring for their offspring via a video
camera installed on the McGuire Woods building and eagerly
anticipate their return in the coming weeks.
Raptor
Identification and Conservation
 With the
exception of vultures, which will be covered separately, raptors
share the following features: powerful feet with sharp, curved
talons used to capture their prey, a sharp, hooked beak for
cutting and tearing meat, and keen eyesight. While owls
predominantly hunt at night, all other raptors are diurnal or
daytime predators.
While
people today enjoy watching hawks and eagles soaring
majestically high overhead, it wasn't all that long ago when
raptors were wrongly persecuted as "varmints". Widespread use of
DDT following World War II further decimated populations of many
of these top predators. The bald eagle, peregrine falcon and
osprey were especially hard-hit. Native to Virginia's Allegheny
and Blue Ridge mountains, the peregrine was extirpated as a
state nesting species by the 60s and all were placed on both the
federal and Virginia state endangered species list. Following
the ban of DDT in 1974, raptor populations began to slowly
recover. Osprey have now been de-listed and the bald eagle
numbers have increased to the point where it is currently under
consideration for federal de-listing from its current threatened
status.
As the
Commonweath's wildlife agency, the Virginia Department of Game
and Inland Fisheries played a lead role in the restoration and
management of peregrines in the state. Beginning in 1978 on the
Eastern Shore, state biologists used a method known as "hacking"
to re-introduce peregrines. This process involves placing 3-6
month-old chicks into a protective box at a release site. Food
is provided daily, but interactions with humans are kept to an
absolute minimum. Ten to 15 days later, when the young falcons
are able to fly, the box is opened and the birds released. Food
is provided until the birds are able to hunt successfully. There
are now 17 known breeding pairs in the Hampton Roads and Eastern
Shore and another pair has successfully nested in downtown
Richmond. Visit the Falcon section of
our Web site for more information about peregrines and our
FalconTrak program, which
allows biologists to track peregrine movement and migration
through satellite technology. Peregrines were taken off the
federal endangered species list in 1999, but are still protected
as a State Threatened species in Virginia.
 Falcons
The
peregrine is one of two species of falcons that nest in
Virginia. The other, the American kestrel, is North America's
smallest raptor. The s lightly larger merlin is common winter
visitor, especially to the tidewater region. Falcons belong to a
different family than that to which most hawks and eagles
belong. Their long, pointed wings and long compressed tails are
adapted for the high-speed predatory dives. Considered the
world's fastest bird, peregrines can achieve speeds up to 200
mph during a dive. Kestrels can be seen "kiting" or hovering in
the air over potential prey.
Hawks
Six species
of hawks nest in Virginia: red-tailed, red-shouldered,
broad-winged, Cooper's, sharp-shinned, and the Northern harrier.
The red-tailed hawk is perhaps the one with which most people
are familiar, as it is commonly seen perched along roads and
interstate highways, especially during the winter months.
Red-tailed along with red-shouldered and broad-winged, are known
as buteo hawks. Buteos typically soar in high circles and have
long, broad wings and rounded, fan-like tails. Broad-winged
hawks, more commonly seen in the western Piedmont and mountains,
are famous and unique among raptors for migrating in large
groups known as kettles, with numbers often recorded in the
thousands.
 Cooper's and
sharp-shinned hawks belong to the group known as accipiter
hawks. Similar in overall appearance (Cooper's are the larger of
the two species), they both have short, wide, rounded wings and
long, narrow tails. These features allow them to make the quick
maneuvers necessary to capture songbirds, their favored prey. If
you have spotted a hawk hanging out by your backyard feeder, it
was most likely one of these two.
An interesting feature common to most raptors is the fact that females are most often larger and heavier than males. Known as reverse sexual dimorphism, the disparity between the sexes increases as a species’ prey size and speed increases. A harpy eagle female may be twice as large and heavy as its mate! Biologists believe this allows for a greater variety of prey to be captured by mated pairs.
Harrier
The Northern
harrier, formerly known as the marsh hawk, is a low-gliding hawk
most easily distinguished by its white rump patch just above the
tail. As its former name would imply, it is most commonly seen
flying low over our coastal marshes. Continued loss of this
habitat, however, has led to declining numbers of this species
and it is now on the state's "species of special concern" list.
Owls
Owls are
supremely adapted as nocturnal raptors. Their exceptionally
large eyes maximize their ability to see in dim light. To match
an owl proportionately, our eyes would have to be as big as
basketballs! Their soft feathers allow for virtually silent
flight. Many species have facial discs that help capture sound
and off-center ear openings that allow them to triangulate prey
location. Virginia has four species of owls that regularly nest
in the state: the great horned, barred, barn, and Eastern
screech-owl. In addition, both the short-eared and northern
saw-whet owls, common winter residents, have also been known to
breed here. Both the barn owl and the northern saw-whet are on
the species of special concern list.
Vultures
Vultures have
historically been grouped with other raptors on the basis of
their overall appearance. Often seen soaring high in the sky,
they are often mistaken for hawks or eagles.
One of Virginia's two vultures, the turkey vulture, unlike most all other birds, has a keen sense of smell, which it uses to locate its food. The other, the black vulture, is not so well endowed, but takes advantage of the turkey vulture's sharper senses by frequently following it to its next meal.
However, it has
recently been determined that the seven species of New World
vultures are more closely related to storks than to the hawks
and eagles with which they were originally grouped. Unlike all
other raptors, vultures are not birds of prey. They feed solely
on carrion, preferring animals that have been dead for two to
four days. This certainly explains why they, unlike all other
raptors, lack strong, grasping feet and talons. Feeding on
carrion has led to a number of other vulture adaptations. Long,
broad wings allow for many hours of effortless soaring. The
elevated hind toe and blunt talons allow for easier walking.
Their bare heads keep otherwise-present feathers from getting
dirty and specialized enzymes and bacteria allow them to eat
contaminated meat.
Watching
for Raptors
Late winter
and early spring is an excellent time to be on the look out for
raptors in your area. Nesting activities have already begun for
the bald eagle and many buteos and owls; falcons, vultures and
the osprey will begin in March, and accipiters in April. While
some North American raptors over-winter, others, including
falcons and accipters, migrate to warmer climates. Many people
enjoy heading to Virginia's well known viewing sites to observe
fall migration, especially witnessing the kettles of broad-wing
hawks that may number in the thousands. Included among the most
popular sites are Snicker's Gap, west of Leesburg, Rockfish Gap,
north of Charlottesville, off of I-64, Harvey's Knob overlook
along the Blue Ridge Parkway north of Roanoke, and
Kiptopeke
State Park on the Eastern Shore. Raptor migration begins in late
August, peaks in late September and continues through mid to
late October.
For More
Information
If you're
interested in learning more about raptors, the
Raptor
Conservancy of Virginia and the
Peregrine
Fund will provide you with additional
information and pictures of both Virginia species as well as
raptors from around the world. You can also follow hawk
sightings at the Virginia Society of Ornithology by subscribing to the VA-Birds listserve
or contacting your local bird club. |
