Double-crested cormorants are large, dark-colored birds that make their living diving beneath the surface of the water and pursuing fish, their favorite quarry. While clumsy-looking on land or when on favorite perches, cormorants are both agile and swift in the water.
While feathers are waterproof simply due to their physical structure, the cormorant’s feathers are “wettable,” and quickly become water-logged, reducing the bird’s buoyancy and increasing its swimming efficiency. In addition, the bones of cormorants, unlike most other birds, are dense and heavy.
While both adaptations help the bird pursue its swift underwater prey, heavy bones and water-logged feathers makes flight more difficult. Cormorants are often seen holding their wings spread to facilitate drying (not warming as in other birds) and when taking off must often “patter” across the surface of the water to build up sufficient flying speed before taking to the air.
- Flocks often fly in long lines or in loose “V” shaped flocks.
- The feathered tufts on its head for which it is named are difficult to discern, although it is the only cormorant found in the Midwest.
- A flock of cormorants is called a "gulp."
- Key ID Features: Large, black bird often perched in dead trees or on riverside driftwood. May fly in loose “V” shaped flocks.
- Present in Park: Late March through October. Look for these birds in the Pigs Eye Lake area near Grey Cloud Island or near the Stone Arch Bridge in Minneapolis.
- Habitat: Large rivers, wetlands, and lakes. Nests are clumsy, stick affairs located in trees. Nests in colonies, often with other species.
- Voice: Guttural croaks. Listen