Back to Nature (Published on - May 18, 2005)
The tenacious double-crested cormorant
Double-crested cormorants are one of 38 age old species of cormorants worldwide, and one of six species in North America.

Historically, cormorants have lived with humankind for thousands of years. Florida’s most common cormorant is the double-crested cormorant. It is named for the two small tufts of feathers on either side of its head, which appear on the adults in spring plumage, although the crests are rarely seen. The word cormorant is derived from the Latin name corvus marinus, meaning “sea crow.”

Cormorants are often mistaken for the anhinga but the more common cormorant has a slender hooked-tip bill and orange facial skin. Both birds can be observed perched while drying their wings outspread in the sun. Each species lacks waterproofing agents on their plumage, which increases the bird’s efficiency to remain underwater, but eventually leads to waterlog and the need to dry their plumage.

The tenacious cormorant has made a successful recovery after its drastic decline in the ’70s which was attributed to the wide-spread use of the pesticide DDT. Once a ban was placed on the use of DDT, a persistent toxic chemical, hundreds of species of birds, including the cormorant began a slow recovery. The double-crested cormorant is widespread throughout North America and Mexico and in some areas it is considered a nuisance by fishermen.

Cormorants are often referred to as “skags or shags” by the fishermen. In many cases the cormorant is falsely believed to be the enemy of fishermen. In recent years thousands of cormorants have been legally killed and thousands of nest eggs oiled in the U.S., Canada and Britain in a misguided attempt to balance nature with commercial ventures and welfare.

Groups such as the Humane Society of the United States, Defenders of Wildlife, Fund for Animals, and the Animal Rights Foundation of Florida, challenged the U.S. Fish and Wildlife Service’s decision to authorize the wide-scale killing of double-crested cormorants throughout the country.

The U.S. Fish and Wildlife Service has been undertaking a national, two-year Environmental Impact Study to thoroughly examine available information, and the responsibility for cormorants rests with the federal government through the U.S. Fish and Wildlife Service. The impact study will be a basis for development of a National Cormorant Management Strategy.

The Canadian Ministry of Natural Resources is undertaking a five-year cormorant program to monitor the potential negative impact of the growing population of double-crested cormorants on local fish stocks, wildlife populations, habitat and vegetation, under Ontario’s Fish and Wildlife Conservation Act.

In some parts of our world the fishing skills of cormorants are utilized by humans. In Southern China the cormorant is harnessed by the Yangshuo fishermen by attaching a ring or a loop of twine around its neck that prevents it from swallowing as it dives to catch fish for its owner. Cormorant fishing is an honored tradition and profession handed down from generation to generation among families.

Cormorants hunt food primarily by swimming and frequently peering underwater. When prey is spotted, they dive after it. Cormorants have the ability to dive to a depth of 100 to 200 feet but its diet consists mostly of small, largely noncommercial, shallow-water fish, as well includes: squid, crustaceans, frogs, tadpoles and insect larvae. The majority of the cormorant’s diet is invasive, nonnative species such as alewives and round gobies, which are destructive to the ecosystem, noncommercial species such as sticklebacks and extremely abundant species such as yellow perch.

Research indicates that no state or federal agency in the U.S. has found definitive evidence that cormorants are causing significant negative impacts on fisheries, except on the aquaculture industry: Such as farm raised catfish.

The feathers of the cormorant are solid, glossy, greenish-black except in the immature stages when the bird has a slightly tan appearance. The cormorant has a gular area (throat pouch) squared off and yellow-orange, extending straight down across the throat. Length: 27 inches. Wingspan: 50 inches.

Cormorants nest in colonies. The platform nest is built near water or high ground for example: High atop a large bromeliad. There are between three -to four eggs, bluish white, incubated by both male and female within 25 to 30 days.

The age-old, globally adaptable cormorant continues to combat against human encroachment, human misunderstanding, misguided lawmakers, environmental disasters and commercial eco-destruction. Cormorants have managed to survive our intrusions upon their way of life year after year as committed mates together against adversity.

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