The Why and How of Satellite Collaring Caribou
From way up there in space the satellite can "see" a patch of the Earth about 3,000 miles (5,000 km) wide. At the speed that they travel, they have about10 to 14 minutes to register thecollar's signal before they go too far and lose it.
The collars on the Porcupine Caribou are programed to transmit a signal for 8 hours one day a week. At this rate, the collars should have battery power for 18 months. This seems to be a good program because collars are really expensive. One collar costs about $2700!
Do collars get in the way of the caribou? As a general rule, the collar total weight should be no more than 4% of the caribou's weight. What is the weight limit on a 200 pound caribou?
Do the Math!
How Do You Collar a Caribou?
A second method involves a helicopter and a special tool called a net gun.Once the pilot locates the animal targeted for collaring, the shooter uses the net gun to propel a large net over the front half of the cow. The caribou is strong and requires a couple of people to get her under control. Her legs are tied to prevent because a caribou can kick really hard. Once they are tied the animal calms down and the collar can be put on. Scientists can also take measurements and blood samples.