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as access to water. At the start of the twentieth century, popula-
tions of the greater sage grouse topped 20 million. Today, says
the US Fish and Wildlife Service, only an estimated 200,000 to
500,000 of the iconic birds remain in the western United States.
This decline has occurred largely because oil, gas, and other
A monarch caterpillar feeds on milkweed. Farmers
who have taken part in habitat exchange programs
have planted milkweed and other native plants
along farm roads to provide badly needed habitat for
endangered wildlife such as the monarch butter y.
