Despite the fact that a few months ago an analysis published in the journal Global Change Biology indicated an overall annual increase of 1.36 percent in the relative abundance of monarch butterflies in their summer places, data contrary to the declines reported for the populations of winter in Mexico and California in recent years, and suggests that successful survival and summer reproduction in North America outweighed winter losses, the International Union for Conservation of Nature has added the monarch butterfly to the list of endangered species.
Due to its rapid decline
Monarch butterflies, with their distinctive orange, black, and white colors, are perhaps the best-known butterflies in North America and around the world. They are also famous for making their annual late summer migration from southern Canada and the northern and central US to southern California, Florida, and Mexico. During these migrations, the butterflies travel thousands of kilometers and are at considerable risk of mortality. After spending the winter in the mountains of central Mexico, the butterflies migrate north and reproduce in several generations over thousands of kilometers. . Hatchlings arriving in southern Canada begin the journey back to Mexico in late summer.
Now, the International Union for Conservation of Nature has classified the migratory monarch butterfly ( Danaus plexippus plexippus ) as “endangered,” that is, two steps away from extinction. The organization estimates that the monarch butterfly population in North America has declined between 22% and 72% in 10 years, depending on the method of measurement. “What we’re concerned about is the rate of decline,” said Nick Haddad , a conservation biologist at Michigan State University. “It’s very easy to imagine how quickly this butterfly could become further endangered.”
In this case, biologists have found that the western butterfly population experienced a devastating 99.9 percent decline due to habitat loss, increased use of agricultural herbicides and pesticides, and climate change.
Its importance in ecosystems
Monarch butterflies are very important pollinators. In the Americas, this work is more than crucial. In North America, millions of monarch butterflies make the longest migration of any insect species known to science. They carry seeds and nectar with them to support many of the foods we eat; we depend on the work of pollinators .
The IUCN estimates that the total population across the continent has shrunk by up to 72 percent in the last decade, spelling trouble for birds and the farming industry. Non-migratory monarch butterflies in Central and South America were not designated as endangered, only the migratory ones.
The monarch butterfly joins the 147,517 species on the IUCN Red List. In addition to her, the tiger ( Panthera tigris ) has also been re-assessed, revealing 40% more tigers since the last assessment in 2015.
Referencia: Opposing global change drivers counterbalance trends in breeding North American monarch butterflies
Michael S. Crossley, Timothy D. Meehan, Matthew D. Moran, Jeffrey Glassberg, William E. Snyder, Andrew K. Davis
First published: 10 June 2022