Linking the continental migratory cycle of the monarch butterfly to understand its population decline
Threats to several of the world’s great animal migrations necessitate a research agenda focused on identifying drivers of their population dynamics. The monarch butterfly is an iconic species whose continental migratory population in eastern North America has been declining precipitously.
Recent analyses have linked the monarch decline to reduced abundance of milkweed host plants in the USA caused by increased use of genetically modified herbicide-resistant crops.
Mexico’s monarch butterflies are suffering from an usual cold weather system that began two days ago with severe rain, wind, and cold temperatures battering butterflies to the ground.
As snow falls in the Monarch Biosphere, conservation of the other end of the monarchs’ life is criticized as inadequate. U.S. conservation groups today issued a suit against the government for failing to protect the monarchs under the Endangered Species Act.
A major global assessment of pollinators is raising concerns about the future of the planet’s food supply.
A U.N.-sponsored report drawing on about 3,000 scientific papers concludes that about 40 percent of invertebrate pollinator species (such as bees and butterflies) are facing extinction. Vertebrate pollinators (such as bats and birds) are somewhat better off by comparison — 16 percent are threatened with extinction, “with a trend towards more extinctions,” the researchers say.
Monarch butterflies have made a big comeback in their wintering grounds in Mexico, after suffering serious declines, experts said Friday.
The area covered by the orange-and-black insects in the mountains west of Mexico City this season was more than three and a half times greater than last winter. The butterflies clump so densely in the pine and fir forests they are counted by the area they cover rather than by individual insects.
Once the passenger pigeon was the most abundant bird in North America, numbering in the hundreds of millions, if not billions. It would take several hours for flocks to pass a single spot, their wing beats so loud it was hard to carry on a conversation.
But by the late 1890s, they were gone from the wild and less than 20 years later, totally extinct. Could monarch butterflies see the same fate?
Forty years ago, amid a forest swirling with millions of monarchs, an aging scientist found a thumbnail-sized sticker placed by two Minnesota schoolboys and solved a decades-old mystery.
Dr. Fred Urquhart, a Canadian zoologist, had searched for the wintering grounds of the monarch since 1937. At the time, no one knew where the monarchs came from each spring. In pursuit of an answer, Urquhart and his wife, Norah, created thousands of monarch tags — tiny stickers that adhered to wings — and distributed them to butterfly enthusiasts throughout North America.
Two environmental groups filed a notice of intent to sue the U.S. Fish and Wildlife Service today over its failure to protect the monarch butterfly under the Endangered Species Act.
The Center for Biological Diversity and Center for Food Safety petitioned for the monarch’s protection in August 2014, following a more than 80 percent decline in the butterfly’s population over the past two decades. In December 2014 the agency issued an initial positive decision on the petition and launched an official review of the butterfly’s status.
They fly through the Louisville area each year on their way from Canada to Mexico — an iconic flutter of orange and black that has taught generations of Americans about the biology of life cycles and metamorphosis, but now may be at risk of vanishing.
Monarch butterfly populations have plummeted so much that the U.S. Fish and Wildlife Service now believes there might be reason to protect them under the Endangered Species Act.