x
Breaking News
More () »

Beloved monarch butterflies now listed as endangered

Environmentalists say the population of monarch butterflies in North America has declined between 22% and 72% over 10 years, depending on the measurement method.

WASHINGTON — The monarch butterfly took a step closer to extinction Thursday, as scientists put the iconic orange-and-black insect on the endangered list because of its fast dwindling 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.

The group estimates that the population of monarch butterflies in North America has declined between 22% and 72% over 10 years, depending on the measurement method.

According to Monarch Joint Venture, a national partnership of 120 public, private and governmental organizations, measuring the population has proven very difficult because of the massive migration patterns of such a small insect.

"It's challenging to really truly measure this insect that spans North America because there are two, distinct populations," said Wendy Caldwell, Executive Director of Monarch Joint Venture. "There's a population west of the Rocky Mountains and a population east of the Rocky Mountains. These two populations have both experienced dramatic declines, but the eastern population, that we see here in Minnesota, is much larger."

Though population counts are often done while the butterflies are more condensed in the south, Caldwell says national efforts to track and expand milkweed habitats across migration routes will be critical to protect the dwindling population.

"We have dedicated volunteers all across the US who are out there counting and trying to help us assess when and where Monarchs are across the US and Canada," Caldwell said. "We're also beginning to use remote sensing and artificial intelligence. We're flying drones over these vast grassland habitats to see if we can detect and count stems of common milkweed."

For information on how to volunteer or plant Monarch and other pollinator habitat, visit the Monarch Joint Venture website.

“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 was not directly involved in the listing, estimates that the population of monarch butterflies he studies in the eastern United States has declined between 85% and 95% since the 1990s.

In North America, millions of monarch butterflies undertake the longest migration of any insect species known to science.

After wintering in the mountains of central Mexico, the butterflies migrate to the north, breeding multiple generations along the way for thousands of miles. The offspring that reach southern Canada then begin the trip back to Mexico at the end of summer.

“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.

A smaller group spends winters in coastal California, then disperses in spring and summer across several states west of the Rocky Mountains. This population has seen an even more precipitous decline than the eastern monarchs, although there was a small bounce back last winter.

Emma Pelton of the nonprofit Xerces Society, which monitors the western butterflies, said the butterflies are imperiled by loss of habitat and increased use of herbicides and pesticides for agriculture, as well as climate change.

“There are things people can do to help,” she said, including planting milkweed, a plant that the caterpillars depend upon.

Nonmigratory monarch butterflies in Central and South America were not designated as endangered.

The United States has not listed monarch butterflies under the Endangered Species Act, but several environmental groups believe it should be listed.

The international union also announced new estimates for the global population of tigers, which are 40% higher than the most recent estimates from 2015.

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.

In the past decade, tiger populations have increased in Nepal, northern China and perhaps in India, while tigers have disappeared entirely from Cambodia, Laos and Vietnam, said Miquelle. They remain designated as endangered.

Watch more Breaking The News:

Watch all of the latest stories from Breaking The News in our YouTube playlist:

Paid Advertisement

Before You Leave, Check This Out