The population is expected to undergo a sizable rebound this winter due to favorable spring and summer weather, but monarchs need a very large population size to be resilient to threats from severe weather events. A single winter storm in 2002 killed an estimated 500 million monarchs — eight times the size of the entire current population. Severe weather is expected to take a toll on the population later this winter due to the strong El Niño this year.With a lawsuit, Fish and Wildlife would be forced into committing to a "legal binding date" for its final decision to either propose the monarch's protection under the Endangered Species Act, reject protection, or add the butterfly to a candidate waiting list for protection, the press release says.
Although the Fish and Wildlife Service has announced that it will provide a total of $3.2 million to support monarch conservation projects, that total falls far short of the funding that would be required by Endangered Species Act protection to restore enough monarch habitat to ensure the butterfly’s future.The decrease in population is largely attributed to the "widespread planting of genetically engineered crops in the Midwest, where most monarchs are born," the release says. A herbicide used by Monsanto kills milkweed, which is the butterflies sole source of food. Also, the center estimates that in the last two decades, the butterflies have lost more than 165 million acres of habitat (roughly the size of Texas).