[ti:Monarch Butterfly Count Nears 30-Year Low]
[al:As It Is]
[ar:VOA]
[dt:2025-02-16]
[by:www.voase.cn]
[00:00.00]An American nonprofit group says the number of monarch butterflies spending the winter in the western United States has dropped to its second-lowest mark in nearly 30 years.
[00:16.58]The Xerces Society for Invertebrate Conservation, based in Oregon, said the causes for this include the use of chemicals to kill insects, known as pesticides.
[00:32.57]The group also blames reductions in habitat and climate change.
[00:37.75]Monarch butterflies are known for their clear orange-and-black markings.
[00:44.57]They live across North America.
[00:47.71]Monarchs in the eastern United States spend the winter in Mexico.
[00:54.07]The World Wildlife Fund, a non-profit based in Switzerland, counts them there but has not yet released data for this year. 
[01:04.54]Monarchs west of the Rocky Mountains usually spend the winter along the California coast.
[01:11.07]The Xerces Society for Invertebrate Conservation has been counting western overwinter populations in California and Arizona for the last 28 years. 
[01:25.84]The highest number recorded was 1.2 million in 1997.
[01:33.07]The organization announced Friday that it counted just 9,119 monarchs in 2024, a decrease of 96 percent from 233,394 in 2023. 
[01:51.78]The total was the second lowest since the survey began in 1997.
[01:58.62]The record-low count was 1,901 monarchs in 2020.
[02:04.58]The survey noted that a place in Santa Barbara that saw 33,200 monarchs last winter had only 198 butterflies this year.
[02:17.19]Monarchs across North America face increasing threats. 
[02:22.77]One is the supply of a plant, milkweed, which they feed on as caterpillars.
[02:30.02]Monarch Joint Venture is a nonprofit group based in Minnesota that aims to protect monarchs. 
[02:37.23]The group said milkweed has been disappearing because of dry weather, wildfires, agriculture and urban development.
[02:47.19]The Xerces Society said pesticides might be on the remaining plants.
[02:53.18]Emma Pelton is a biologist with the Xerces Society. 
[02:58.13]She said it is unclear what caused such a sharp decrease in the western population in just one year.
[03:06.26]The monarch population is already small, she said, and heat above 37.7 degrees Celsius in the western states last year might have slowed breeding.
[03:19.23]Monarchs suffer when the temperature gets up to 37.7 degrees Celsius and any temperatures above 42.2 degrees Celsius will kill the insects, Pelton said.
[03:34.96]The western states saw a heat wave in July with temperatures in some areas well past 37.7 degrees. 
[03:44.91]Palm Springs, for example, reportedly reached a record 51.1 degrees Celsius on July 5. 
[03:54.32]Another heat wave hit northern California in early October, with several cities breaking heat records.
[04:03.28]Pelton said that it is too early to tell what long-term effect the sharp drop might have on the overall western monarch population.
[04:15.25]Insects can reproduce very quickly, Pelton said. 
[04:19.68]After a low point of 1,901 butterflies in 2020, the population recovered to 247,246 insects the following year, an increase of nearly 13,000 percent. 
[04:39.18]The year after that the survey recorded 335,479 monarchs.
[04:46.34]"This is bad news," Pelton said of the 2024 population drop.
[04:52.64]"But we have seen incredible recovery. This doesn't mean we're not going to have western monarchs."
[05:00.47]The U.S. Fish and Wildlife Service announced in December 2024 that it wanted to list monarchs as threatened.
[05:09.68]Such a move would ban people from killing or transporting them. 
[05:15.02]The proposed change would also ban property owners from making changes to their property that would make it unusable to the butterflies.
[05:25.18]For example, removing all milkweed from a property would by banned by law.
[05:30.78]Earthjustice is an environmental nonprofit legal group based in San Francisco.
[05:37.65]It asked the Environmental Protection Agency in December 2024 to require testing of pesticides' effects on insects such as bees, moths and butterflies.
[05:51.53]I'm Jill Robbins.