Is there good news for monarch butterflies? Researchers disagree | MarketingwithAnoy

Last month, the government officials met in Washington, DC, for the first time Monarch Butterfly Summitlike the dairy plant in “Monarch Waystations”, Now ubiquitous across American lawns, began to flourish. Like everyone else, they were concerned about the fate of the iconic insect after decades of remarkable population decline in the butterfly’s winter colonies.

There are two different (but genetically identical) populations of monarchs in the United States, and both are migrating. Monarchs west of the Rocky Mountains spend their winters in Southern California, while east of the area they fly thousands of miles from as far north as Ontario to central Mexico, where they wait the cold months out in the stands of oyam fir trees. Since the mid-90s, researchers have found that the number of butterflies coming to Mexico has dropped by about 70 percent. They blame bad weather, deforestation and car collisions for the decline.

Alone in 2020 26 percent fewer Eastern monarchs it reached Mexico than the year before, after being overcome by storm and drought. Those who survived the journey found their already small wintering grounds reduced by illegal logging. In 2019, concluded researchers that the Western monarch “hovered at its quasi-extinction threshold” after a 97 percent reduction in that subpopulation since the 1980s.

So it may be surprising – and perhaps controversial – that one recent study published in the journal Global change biology suggests that some populations of monarch butterflies are actually on increase. “There is no monarch butterfly apocalypse,” said Andrew Davis, an ecology professor at the University of Georgia (UGA) and co-author of the study. “At least not in the United States.”

His group’s work is unusual because it focuses on the insects’ breeding grounds, not their migrating stopovers. In other words, the team looked at counts taken in the summer throughout the United States, not in the winter in Mexico or Southern California. Davis and his co-researchers relied on more than 135,000 monarch observations made on both sides of the Rockies between 1993 and 2018 during the North American Butterfly Associations’ (NABA) annual census. These events encourage citizen researchers to record all the butterflies they see within a 15-mile radius over two days in early July.

While the research team noted that there have been small declines in some regions of the United States, particularly the Midwest and New England, areas such as the southeastern and northwestern Pacific see more monarchs. Overall, the data suggest an overall annual increase of 1.36 percent across the species’ summer distribution, meaning that over the 25-year period, the summer population of monarchs in the United States has increased by about 35 percent.

Davis says his team’s results show that the butterflies’ fry in the summer outweigh the losses the insects experience in the winter. “They are able to return and repopulate their entire breeding area each year, no matter how many there are in the winter colonies,” he says. “It’s just math. A single female can lay 500 eggs. If the conditions are right, the population will explode.”

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