Crows
are members of the Corvidae, which also includes ravens, jays and magpies.
In the northeast the predominant crow species is the American or common
crow, Corvas brachyrhynchus, a stocky, all-black bird with a large heavy
bill and a body length of 17 to 21 inches. The common crow has a fan-shaped
tail, glossed with purple in strong sunlight. The fish crow may also
occur in this area, particularly in spring, along large rivers and tidewaters.
This crow is slightly smaller (16 to 20 inches) than the common crow
but is glossier in appearance. Less common is the northern raven, which
is hawk-like and much larger (up to 25 inches) than the common crow.
It has a characteristic large, wedge-shaped tail. It has been reported
to occur in Litchfield and Tolland counties in Connecticut.
The American Crow
The prevalent species of this area, the American crow is easily recognized
due to its large size coal-black plumage and distinct caw-caw voice. In
flight, it is distinguished from other blackbirds by its frequent, steady
wing beat with little or no gliding. Crows are one of the most intelligent
and wary birds, have good memories, are good at solving puzzles and are
quick to learn to associate various noises and symbols with food. They
eat almost anything. About one-third of their diet consists of small animals,
including insects, spiders, frogs, snakes and carrion such as traffic-killed
animals. The remainder of the crow's diet consists of vegetable and plant
matter, and even garbage.
Patterns of Behavior
Crows have two broad patterns of behavior. In the fall and winter months,
they roam widely in large flocks; but in the breeding and summer seasons,
they occur in specific areas in small bands.
Crows pair off in early spring, building a nest of twigs, sticks and stems.
The nest may be built on the ground, in areas where there are few trees,
or as high as 60 feet above ground in oaks or pines. Each nest has four
to six eggs that hatch in 18 days; and there is usually one brood each
year. Young leave the nest in about five weeks, forage with their parents
throughout summer and join larger and larger groups as fall approaches.
Huge groups often migrate in late fall or winter, roosting together at
night and flying as far as 50 miles each day to feed.
Feeding Damage
Crows consume various amounts of grains, seeds, corn, wild and cultivated
fruits, watermelons,: tomatoes and potatoes. Small potato plants are pulled
up, and angled holes are eaten out of attached seed pieces. Crows damage
seedling corn plants by pulling the sprouts and consuming the kernels.
Ripening corn is also attacked during the milk and dough stages of development
Ripe tomatoes and watermelons may be eaten, leaving large angled holes
in the fruit.
Nonchemical Control
Several methods of nonchemical crow control are useful.
- Plastic or nylon netting can be placed over tomatoes and watermelons
to keep crows out. Make sure the edges are firmly secured by stakes
or anchored with soil.
- Potato seed pieces or young plants can be protected by maintaining
high ridges early in the season.
- Several reports show that scattering whole corn (presoaked in
water) through a field where crows are damaging newly-planted corn
seedlings
acts as a decoy food source.
- Frightening devices are effective in dispersing crows. Lights,
bright objects and noisemakers work well in scaring birds. Bright
colored aluminum
strips for frightening birds are commercially available. Aluminum
or cloth strips or aluminum pie pans tied to wires stretched
over the planting
also
work.
- Cord, monofilament fishing line or fine wire, stretched at
regular intervals across a planting six to eight feet high,
successfully keeps crows out.
The system works particularly well with staked tomatoes where
the
stakes can be used to support the wire, but is also adaptable
to most other
planting situations. NOTE: The wires can pose a hazard to people
on tractors or
other equipment and should be clearly marked with reflective
tape in areas where equipment will be used.
- Crows can be captured uninjured in commercially produced
steel crow traps.
Chemical Control
Seed treatments may also be used in crow control.
-
Treat seed to prevent damage by crows and other birds.
Two seed-treatment repellents are federally registered
for preventing
crow damage.
One is refined coal tar (Stanley's Crow Repellent)
and the other is copper
oxalate
(CrowChex). When using repellents, follow the label
and all instructions and restrictions.
-
There are no toxic materials currently registered for
control of crows.
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