Cormorants are fish-eating birds that prey on abundant or easy-to-catch species.
Ontario's double-crested cormorant population has increased dramatically over the past 30 years. This rapid population growth has resulted in cormorants now being found throughout the Great Lakes and up to James Bay.
On the Great Lakes, cormorants typically nest on islands or peninsulas to avoid predators. Both male and female birds share in building the nest, incubating eggs and feeding the chicks. Cormorants lay an average of three or four eggs each year.
In all seasons, cormorants need suitable places for night roosting and daytime resting. These sites are often exposed places such as rocks, sandbars or trees near preferred fishing sites.
Where cormorant colonies can be reached by land, young cormorants may be preyed upon by raccoons, coyotes and foxes.
Conflicts happen
Cormorants prefer island and peninsula properties and may come into conflict with landowners when nesting or roosting.
Please keep in mind…
Wild animals have the same basic needs as humans – food, water and shelter. Sometimes, humans and wild creatures come into conflict when animals are trying to meet their basic needs. Often, conflicts can be prevented if we're willing to make small changes to how we think and act.
People and wild animals live side by side in Ontario. We all share responsibility for preventing and handling human-wildlife conflicts. If you must take action against wildlife, please consider all your options and follow all relevant laws and regulations.
Conflicts with Cormorants
How Can I Prevent Conflicts?
Make your property unwelcoming
- Portable propane-fired exploders, sirens, or air horns will scare cormorants off your property but equipment must be moved regularly because they become accustomed to it.
- Bright flashing strobes can disturb cormorants after dark or just before dawn.
- Sound-recorded distress calls of cormorants or other bird species may persuade flocks of them to move from your property
- Sound recordings of eagles or falcons as well as eagle and falcon models or kites may also scare geese away.
- Lengths of shiny or bright materials, flags, or balloons strung between stakes or attached to trees and allowed to move in the wind create a visual distraction that geese may avoid.
How Can I Handle a Conflict?
If cormorants are nesting around your property
- Early and frequent use of deterrents is the best way to prevent cormorants from getting settled around your property.
- Combine motion sensors with a sprinkler that attaches to a spray hose to startle birds.
- Installing a 360-degree sprinkler up in a roosting site or putting bright fluorescent lights up on the roost can also deter birds.
- If you modify the place where the birds roost at night, it will discourage them from settling in.
Lethal action is a last resort
- If a cormorant is damaging your property, you may take lethal action to protect your property but you must not cause unnecessary suffering to the bird. You must follow firearm regulations and bylaws.
- You may also hire a wildlife control agent to act on your behalf.
For more information and assistance…
To locate a local wildlife control agent…
• Speak with your neighbours, family, and friends.
• Look for "animal control" in your phone book or online.
For information on cormorants…
• Call your local Ministry of Natural Resources office or the Natural Resources Information Centre at 1-800-667-1940.
• Check out Project WILDSPACE
• Canadian Wildlife Service Fact Sheet on Cormorants
• Ministry of Natural Resources - Review of the Status and Management of Double-Crested Cormorants in Ontario
Return to Living with Wildlife - Species Fact Sheets list
