IDENTIFICATION stay under water up to 70 sec- Cormorant is the common onds. They eat mostly fish and name for 30 of sometimes small inverte- that occur world-wide. Six are brates such as crayfish. Cor- found in North America. The morants use their webbed feet most common North Ameri- to propel them underwater. can cormorant is the double- Cormorants run along the sur- Cormorants are found through- crested cormorant. Adults are face of the water to gain out the northern United States mostly black with slender enough speed for flight. and Canada. In the winter , long snake-like necks they are found along the and short stiff tails. They often Cormorants have no oil glands and along rivers and use their tail as a prop when to grease their and lakes in the they perch. They have a repel water. Therefore they central northern states and in hooked bill and some birds sometimes perch with their east Texas and Louisiana. have a yellow-orange throat wings spread out in the sun patch. Cormorants have short and breeze to dry their feath- legs and webbed feet for ers after fishing underwater. swimming. Both the legs and feet are black. Cormorants are sociable birds and almost always nest HABITS in colonies. Their nests Cormorants are aquatic birds consist of sticks and other drift found on inland material and are built on the lakes, rivers and ground or in trees near water. swamps as well They usually lay three to four as on the . . Both male and female Double-crested birds share nest-building, incu- cormorants are bation and feeding of the daytime feeders chicks. The birds have the un- that hunt alone usual habit of incubating their or in flocks that eggs by wrapping the webs of may number their feet around them. The 600 birds. young become fully independ- Cormorants feed ent after about ten weeks. by diving and swimming un- derwater. They can dive to depths of 5 to 60 Phalocrocorax auritus feet below the surface and Double-Crested Cormorant

Improving water quality by preventing pollution has resulted in a thriving cormorant population.

Living in harmony . . . Living in conflict . . . Most of the time, cormorants and humans live · Cormorants consume commercially in harmony. reared fish · People enjoy watching these diving birds · Cormorants destroy trees and natural in their natural environment vegetation · Cormorants are an important regulator of · Cormorants can displace desired nesting nature’s complex food web, helping to keep birds and fish from overpopulating streams and · Cormorants pose hazards to aircraft lakes · Cormorants can carry diseases that are · Cormorants are an important environ- infectious to humans mental indicator species —-when · Cormorants may eat the same fish that rec- cormorants are healthy and thriving then reational and subsistence fishermen catch the environment is healthy and thriving

Many control methods are used exploders, scarecrows, flash Some lethal control methods that to prevent damage caused by tape, distress call units, might be used after obtaining cormorants. Both lethal and sirens/horns and vehicles. permission from both state and non-lethal methods are used. · relocating winter roosts away federal agencies include: Often a combination of methods from aquaculture sites · shooting cormorants works the best. Using a combina- · providing alternate food · oiling or removing eggs tion of management methods is sources · nest removal called integrated pest manage- · modifying aquaculture ment (IPM). The purpose of IPM practices is to reduce damage done by the birds rather than eliminate cor- morants.

Some non-lethal methods include: · completely or partially enclosing small ponds with screen, netting or overhead wire · using frightening devices such as pyrotechnics (projectile firecrackers), eyespot balloons, automatic

For over 2,000 years the Chinese and Japanese have been using cormorants to help them fish.

Aquaculture, fish farming, is the raising and selling loses millions of dollars worth of fish to cormorants. of fish for profit. Aquaculture is one of the fastest In Mississippi, cormorants have been reported to growing industries in the U.S. Catfish, trout, eat more than $3 million dollars worth of catfish salmon, striped bass and ornamental fish are the each year. Producers spend more than $2 million most common fish raised. Cormorants hunt where trying to prevent damage. there are a lot of fish. This is exactly what the cor- morants find at fish farms. The aquaculture industry

The word “cormorant” comes from the Latin name der the Migratory Treaty Act. By the 1980s corvus marinus which means “sea crow.” Other most cormorant populations began to increase. names used for the double-crested cormorant are This increase was due to reducing human perse- water turkey, water buzzard, crow-duck, Farallon cution, reducing levels of environmental contami- cormorant, Florida cormorant, shag, Taunton nants, especially DDT, an abundant supply of fish turkey and white-crested cormorant. (in part from the expanding aquaculture industry), and development of good colony sites on man- In Asian countries, the cormorant is used to made lakes. Today, cormorant populations are at harvest fish. A ring is placed around the bird’s neck an all-time high. so it cannot swallow the fish. The cormorant dives into the water, catches the fish and brings it back to the boat where the handler grabs the fish.

Double-crested cormorants were abundant during the 1940s. However, the numbers of cormorants declined in the 1960s and 1970s. This decline was due to humans collecting eggs for food and de- stroying the birds’ nests. Contaminants in the water and food supply are also believed to have lowered their numbers. In 1972 the double-crested cormo- rant was added to the list of species protected un-

Calculating the cost . . .

The cost of frightening programs varies depending on the What would the costs be for the following farm? types of techniques used, the species of birds involved, Labor (15 hours @ $9/hr) ______the size of the farm and road conditions. Following is an Vehicle Expense (250 miles @ $.25/mile) ______example of daily cost for a typical scaring program on a Pyrotechnics farm of 500 acres of ponds. (200 rounds @ $36.50/100 rounds) ______Labor (10 hours @ $8.00/hour) $ 80.00 Ammunition for harassment Vehicle expense (100 miles @ $.30/mi) $ 30.00 (25 rounds @$5.24/25 rounds ______Pyrotechnics & Ammunition $ 16.30 (used to scare birds) What is the daily total? ______Total Costs: $126.30 How much would a frightening program cost at a farm for How much would it cost for 90 days? ______150 days?

ACROSS: 2 – catfish, 3 – aquaculture, 4 cormorant, 5 – environmental indicator, 7 – integrated pest management, 8 – invertebrate DOWN: 1 – pyrotechnics, 2. colonies, 3. aquatic, 6. webbed

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ACROSS 7. What IPM stands for 2. A type of fish raised in farms 8. Crayfish is an example of this type of 3. Another word for fish farming DOWN 4. Common name for several web-footed black 1. Firecrackers are an example of this birds with slender beaks 2. Groups of birds nesting together are called… 5. When the decline in the number of a species of 3. Having to do with water animals indicates pollution or other problems in 6. This type of foot makes it easier for birds to the environment swim

Wildlife Activity Book and Jack H. Berryman Institute Websites: 1998 Wildlife Issue of the for Wildlife Damage Cc.usu.edu/~rschmidt/welcom. Colorado Reader Management html Colorado Foundation for Utah State University Agriculture Logan, Utah 83431-5210 USGS Patuxent Wildlife Re- P.O. Box 10 search Center Bird Identifica- Livermore, CO 80536 tion: www.mbr-pwrc.usgs.gov

This activity sheet has been developed by USDA Wildlife Services. For more information about cormorants contact your state’s Wildlife Services office or USDA Wildlife Services at 301 734-7921.