Cormorant Control


The Double-crested Cormorant is the most numerous and widespread North American cormorant. It's also the only one that occurs in large numbers inland as well as coastal regions. In Southern Ontario, especially near Lake Ontario, the Cormorant is one of the only fish-eating species seen. The Double-crested Cormorant is quite a large bird with a greenish-black colour.


The Cormorant is often responsible for declines in sport fisheries and for devastating local fish farms. In addition, accumulated fecal matter below nests can kill the nesting trees. When this happens, the cormorants may move to a new area or they may simply shift to nesting on the ground. In their wake the Cormorants have left numerous areas (islands and inlets) that were once vibrant with greenery, completely barren.

In the Great Lakes region of Ontario the Cormorant is also causing havoc for fisherman as they find Cormorants entangled in their nets. In addition, fish populations are declining rapidly as they are consumed by these birds.

Cormorant Control

At Nimby Pest Management we will use a variety of control methods including falconry using eagles, falcons and hawks to chase and re-locate birds. We may also utilize pyrotechnics to scare them off as well as exclusion netting to keep them from settling in ponds on neighbouring properties. Nest removal plays a part in re-locating the birds.

Please be aware: *These birds are protected so a special permit is required.



The Double-crested Cormorant makes a bulky nest of sticks and other materials. It frequently picks up junk, such as rope, deflated balloons, fishnet, and plastic debris to incorporate into the nest. Parts of dead birds are commonly used too. Large pebbles are occasionally found in these nests, and

the cormorants treat them as eggs.


Growing in numbers throughout its range, the double-crested Cormorant poses a problem to fish farms. Their nests often are exposed to direct sun. Adults shade the chicks and also bring them water, pouring it from their mouths into those of the chicks. In breeding colonies where the nests are placed on the ground, young cormorants leave their nests and congregate into groups with other youngsters. They return to their own nests to be fed.


Cormorants are widely distributed across North America. They breed locally along all coasts and along the Great Lakes and the St. Lawrence Seaway. They are also found in Mexico, Belize, the Bahamas, and Cuba. Wintering is seen along Pacific Coast from Alaska to Mexico; along the Atlantic and Gulf coasts from North Carolina to Belize, with smaller numbers northward to New Hampshire; and at inland sites along large rivers and lakes northward to Indiana.