PACIFIC GROVE — Monarch butterfly numbers are down this year entering prime counting season, but experts aren’t panicking yet.
“Butterfly populations are bouncy,” said Isis Howard, an endangered species conservation biologist at the Xerces Society. “The monarch butterfly life cycle is unique in that they have multiple generations present at one time. The super generation’s success is reliant on the previous generation’s success.”
And with last year’s winter storms, she says it likely impacted the breeding population of monarchs, hence the lower numbers. Animals can behave differently year after year, meaning there may be more on the way. “It’s a little early to tell. There might always be a late wave of monarchs.”
The western monarch butterfly is the species that earned Pacific Grove the name of Butterfly Town, U.S.A. Unlike the eastern monarch butterfly, they migrate between northern states like Washington, Oregon, and Idaho before coming to roost in temperate California for the winter. At temperatures below 55 degrees, monarch butterflies cannot fly. Instead, they huddle together in orange and black clusters in the trees until the air warms again. This unusual behavior makes it possible to count them early on cold winter mornings, when they’re still gathered together.
“The monarch butterfly life cycle is unique in that they have multiple generations present at one time,” said Isis Howard, an endangered species conservation biologist at the Xerces Society. “The super generation’s success is reliant on the previous generation’s success.” (Kristel Tjandra — Herald Correspondent)
The annual Thanksgiving count is vital for those who want to ensure the preservation of these butterflies, which are set to be listed as “endangered” by the IUCN Red List of Threatened Species. “By comparing how that number differs throughout the years, we’re able to get a very good idea of how the population is faring over time,” said Natalie Johnston, community science coordinator at the Pacific Grove Museum of Natural History. “And then we can start working on what factors contribute to this and what needs to be done in order to have that future population.”
But across the monarch butterfly sanctuaries in Pismo, Natural Bridges and Pacific Grove, the volunteers have noted far fewer butterflies overall. The monarch butterfly count on the Pacific Grove Museum of Natural History, which is updated weekly, currently lists the count at 7,604. Johnston reported that’s far less than the 12,600 butterflies that they counted last year around this same time. Major concerns about how low the numbers had dropped in 2020 were starting to be alleviated when the numbers climbed last year – but this might just be a low year.
The Xerces Society, a conservation group focused on invertebrates, also conducts another butterfly count in January to obtain further data on how monarchs are doing. Earlier this year, they reported a 58% average decrease of monarchs — according to the Xerces Society’s conversations with local volunteers, it was likely due to the rain and wind causing trees to topple, with monarchs still roosting in them. But in Pacific Grove, Johnston noted the populations …read more
Source:: The Mercury News – Entertainment
