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To Cut Losses of Sheep, Scientists Hope to Pull Wool Over Coyotes' Eyes

December 06, 1987|MATT MYGATT | Associated Press

Moo moo black sheep have you any wool? No sir, no sir, because I'm a cow.

Or at least I think I am.

Blame the confusion on scientists. Dean Anderson and Clarence Hulet are trying to make lambs think cows are their parents.

They have a good reason for trying to behaviorally bond lambs to cattle. They are hoping the hefty elders will guard their foster children against attacks from coyotes.

"The bumper sticker that says, 'Eat lamb, 10,000 coyotes can't be wrong,' is not a figment of the imagination, as we found out," Anderson says.

On the other hand, coyotes usually steer clear of cows.

"In my opinion, cattle have an innate dislike for canines, whether it's a coyote or a dog that's working them," Anderson says. "They will lower their heads and snort and kick at them.

"We saw this type of behavior and thought that if a sheep would stick next to a cow, then a coyote would not do its damage."

193,000-Acre Laboratory

Anderson and Hulet are conducting research on bonding lambs to cattle at the U.S. Department of Agriculture's 193,000-acre Jornada Experimental Range 23 miles north of Las Cruces, N.M.

Anderson is a research animal scientist with the USDA's agriculture research service in Las Cruces and Hulet is a reproductive animal physiologist with the service.

Their experiments are based on research by Konrad Lorenz, an Austrian naturalist and one of the founders of ethology, the study of animal behavior.

Lorenz and two other ethologists received the 1973 Nobel Prize for physiology for their work on animal behavior.

Lorenz described the instinctive process of imprinting by which an animal may learn to identify its owner as its parent.

"We came up with the idea that if it were possible to bond sheep to cattle, we might not have the predation loss," Anderson says.

"In the 10 years we've been on the Jornada, we've had no known loss of any healthy calves to coyote predation."

Heavy Loss of Sheep

Sheep were introduced on the ranch in 1983 and within one year the researchers lost more than 60% of the 102 animals, primarily due to coyotes, he says.

An initial 223-day study on bonding began in December, 1985.

A group of nine lambs and seven amicable yearling heifers were placed in pens for 60 days simply so they could learn to stick close to each other. Cattle and sheep normally do not associate when they are in the same pasture at the same time, Anderson explains.

The study involved lambs 45 to 90 days old because it was impractical to start with day-old lambs.

"At the end of 60 days, the animals were taken to pasture and released, and they stayed together," Anderson says. "They're still together. There was no loss of lambs that were bonded."

Meanwhile, two control groups of sheep, without cattle, were tested in fields during the same period the bonded sheep and cattle were in another field. The two control groups suffered more than 50% losses.

"Evidence indicated all the lambs that were lost were lost due to coyotes," Hulet says.

Wants to Do More Study

Anderson says that while the initial results look very promising, more study is needed.

"We have simply opened the door," he says.

Hulet says the researchers want to find out what happens with larger flocks and larger numbers of cattle.

"There are a lot of other questions," he adds. "We want to make bonding as efficient as we possibly can. We need to know what the critical time is to get a good, enduring bond. How many cattle can we have in relation to the number of sheep?"

Anderson says most rangeland can endure grazing from two or more species.

"Cattle eat grass and sheep will eat weeds," he says. "Most rangeland has a combination of grasses, weeds and shrubby plants."

If bonding could be made to work, Anderson says: "It would be very ecologically and biologically sound. And we hope that it would make more sense economically."

Other Problems Remain

Bonding is not a panacea that is going to solve all the sheep ranchers' problems, which include foreign competition and production costs such as labor, lease fees, feed and taxes.

The number of sheep in the United States has been dwindling. USDA statistics show there were 19.73 million sheep and lambs in the United States in 1971, compared to 9.93 million in 1986.

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