Corvus brachyrhynchos

American Crows are a familiar sight in almost any environment in North America. Their large, all- black bodies and recognizable “caw- caw“ voice makes them easy to identify. They are very intelligent and savvy birds, having remarkable memories and the ability the solve problems and puzzles. Because of this, they can be formidable pests of certain crops such as corn, potatoes, tomatoes and melons, in damaging lawns where insects are present and they are also notorious robbers of bird’s eggs and nestlings. They may also get a bad rap because of their obnoxious harassment of roosting owls and hawks. On the plus side, they are natural garbage disposals, consuming road kill and edible trash. They may rip up lawns, but that is usually because a population of grubs or earthworms exists. Eating almost anything, a major part of their diet consists of small animals, insects, snakes and frogs, plant matter and carrion.

Behavior

Seldom seen alone, crows are very social birds and often form sizeable flocks. They will form large communal groups and roost in the evening, sometimes travelling thirty or more miles to the site as dusk approaches. During the breeding season, these roosting habits change. Crows can be seen in or along roads picking at carrion. They will harass hawks and sometimes are successful in stealing their catch.

Crows nest in early spring, constructing large nests of stems and sticks. Nests may be anywhere in trees or even on the ground. Preferred trees for nesting are pines and oaks. Juvenile crows forage with their parents, so preferences in foods are passed along to the young by example, as is the case with most birds. Crows can become problems when preferences are established for corn and other vegetables or fruits.

Feeding Damage

Crows will pull up new corn seedlings to get at the kernels, attack ears during the milk and dough stages of seed development of the corn kernels, and can pull up small potato plants. Large angled holes are made in ripe tomatoes and watermelons, rendering fruit useless for marketing. Other fruits, especially apples, can be similarly damaged or eaten outright. Look for large, triangular peck holes in apples, a typical sign of crow feeding. If taller corn plants are damaged, raccoons or sometimes deer may be the culprits, and not crows, even though crows may be feeding on the ears of damaged plants. Mice can also nibble kernels and eat fruits and even tomatoes. Other birds such as grackles and starlings will also eat corn, so crows may be innocent bystanders foraging nearby on non- crop plants or even small animals.

Damage to sweet corn is worse during dry years. Small apple orchards may suffer more damage than larger ones, especially if the larger orchards are near or abut another one. Apples that mature earlier are more damaged than apples that mature later in the year.

Control

The American Crow is classified by the U.S. Fish and Wildlife Service as a migratory game bird and state hunting regulations must comply with federal guidelines. There is a hunting season, but federal guidelines will allow crows to be killed if they are "committing or about to commit depredations upon ornamental or shade trees, agricultural crops, livestock or wildlife, or when concentrated in such numbers and manner to constitute a health hazard or other nuisance." No limit exists at the present time on the number of crows that can be taken during the regulated hunting season. Check the CT. DEEP Upland Bird Hunting Season Calendar for up- to-date information on hunting crows in Connecticut.

Varying tactics usually work best with crows, as they readily get used to visual and sound methods of control. Use different methods and switch around devices to reduce the likelihood of crows becoming familiar with any one control approach, as crows are particularly quick to perceive threats and will work around them.

Plastic or nylon netting can be placed over tomato, potato, and watermelon plants. Secure firmly to the ground to ensure crows cannot pull netting away. Protect potato seedlings and small plants by maintaining high ridges of soil early in the season. Mixed results have been obtained by using a wire grid system several feet above the crop, and this method may have disadvantages when spraying and using machinery are necessary.

Newly planted corn can be protected somewhat by scattering pre-soaked corn seeds between rows as a source of food that is readily obtainable. Some people have reported some success in planting an alternative food crop nearby the crop needing protection, but this may also attract more birds to the area. Seed-treatment repellents such as refined coal tar (Stanley’s Coal Repellant) and copper oxalate are available in some states.

Sound devices may work in some instances. Tapes featuring the distress call of crows trying to escape predators with screaming hawk sounds included at intervals have been effective in dispersing crows from roosting spots and in rural settings. Shell crackers and bird bombs can be effective, but you must be present to set them off when crows are there. Some can be set on timers. Electronic sound devices such as Av-Alarm may also repel birds to some extent. The greater the variation of sounds and loudness or disruptiveness the more effective sound alarms will be.

Combinations of scare tactics work better than just using one method. Owl effigies, especially if a crow likeness is attached to appear as the owl’s victim may offer some protection to crops, and are more effective if the wings and/or head can be made to move. Again, crows will become accustomed to this object if kept in the same place day after day.

Poisons are not recommended for control of crows as non-target birds and animals may also be killed, but there are poisons registered for use in CT for certain sites. There are also repellents that are registered for use in Connecticut with the active ingredients Polybutene or Methyl Anthranilate.

Shooting may work best, if guidelines as to legal permits and federal law are followed. Usually, though, crows are very aware of threats during the day and shooting may provide control more in a dispersal effect than as a population control.

Control efforts should begin as soon as crows show up in crop areas. The more time they spend in a food source area, the more determined they will be to return. Less effort will be needed to remove them when initial attempts to get food are thwarted immediately.

Revised by UConn Home and Garden Education Center 2016.