Given the new data, all of the researchers now believe that western monarch butterflies should be listed as a threatened species under the Endangered Species Act. Crone explained that the listing would help to motivate agencies and landowners to participate in conservation practices.
“Listing would also substantially raise awareness of the plight of monarchs and similar species,” she continued. “For example, many other butterfly species also seem to be less abundant now than 30 years ago.”
The researchers said homeowners can take part in the butterfly conservation effort too. They are encouraged to plant native, locally sourced milkweed plants. Xerces has a milkweed seed finder to help locate vendors. Homeowners should also include other native plants and monarch-attracting wildflowers in their gardens.
“Some common garden flowers, like petunias and geraniums, don’t produce nectar,” Crone explained. “Others, like pansies, provide nectar and are used by native insects.”
The scientists also urge homeowners to minimize “homogenous” land surfaces, like pavement and grass-only lawns, and to support organic and other wildlife-friendly gardening and farming practices.
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At present, Schultz and her team are monitoring where and when monarchs breed across the West. They are working across five states: California, Nevada, Idaho, Oregon, and Washington. They are also involved in a joint five-year project evaluating the importance of species interactions for population viability of rare butterflies, and how these interactions might be impacted by climate change.
The scientists are in talks with scientists in Mexico about collaborating on the larger eastern monarch population that overwinters in Mexico.
The researchers encourage the public to participate in projects in North America, in addition to the Western Monarch Thanksgiving Count, aimed at collecting data about butterfly populations. These projects include the Western Monarch Milkweed Mapper, Project Monarch Health, Journey North, and the Monarch Larva Monitoring Project.
Crone resists the notion that monitoring the decline of butterfly populations is depressing and instead emphasizes researchers’ work at helping species rebound from the threat of extinction.
“We have been successful in helping other species, like the Fender’s blue butterfly, toward recovery in the past,” she said. “If we start now, we are optimistic that monarchs can be restored and maintained in the West, and throughout the US”
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