TScientists have placed the monarch butterfly on the endangered-list due to their declining numbers.
“It’s just a devastating decline,” said Stuart Pimm, an ecologist at Duke University who was not involved in the new listing. “This is one of the most recognizable butterflies in the world.”
The International Union for the Conservation of Nature added the migrating monarch butterfly for the first time to its “red list” of threatened species and categorized it as “endangered” — two steps from extinct.
According to their estimates, North America’s monarch butterfly population fell between 22% and 72% in 10 years. This is based on different measurement methods.
“What we’re worried about is the rate of decline,” said Nick Haddad, a conservation biologist at Michigan State University. “It’s very easy to imagine how very quickly this butterfly could become even more imperiled.”
Haddad, who wasn’t directly involved with the listing, estimated that the monarch butterfly population he studied in the east United States had declined between 85 and 95% over the past 20 years.
Millions of monarch butterflies migrate the most distance of all insects known.
After spending the winter in the central Mexican mountains, butterflies fly to Canada, where they breed multiple generations and travel thousands of kilometers. Once the butterflies have reached southern Canada, their offspring will make the return trip to Mexico.
“It’s a true spectacle and incites such awe,” said Anna Walker, a conservation biologist at New Mexico BioPark Society, who was involved in determining the new listing.
One smaller group lives in California’s coast winters, and then moves to other states west of Rocky Mountains in the spring and summer. This population is experiencing a much more dramatic decline than that of eastern monarchs. There was however a slight rebound in the last winter.
Emma Pelton from the nonprofit Xerces Society monitors western butterfly populations and said that they are threatened by habitat loss and an increased use of pesticides and herbicides in agriculture as well as climate changes.
“There are things people can do to help,” she said, including planting milkweed, a plant that the caterpillars depend upon.
The endangered status of nonmigratory monarch butterflies from Central and South America was not given.
Although the United States has yet to list monarch butterflies as endangered species under its Endangered Species Act (ESA), several environmental groups feel it should.
International Union also released new estimates of the worldwide population of tigers. These estimates are 40 percent higher than 2015’s.
The new figures, of between 3,726 and 5,578 wild tigers worldwide, reflect better methods for counting tigers and, potentially, an increase in their overall numbers, said Dale Miquelle, coordinator for the nonprofit Wildlife Conservation Society’s tiger program.
Miquelle stated that tigers in Nepal, India and northern China have grown in the last decade. However, they have gone extinct in Vietnam, Laos, Cambodia and Laos. They are still considered endangered.
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