SANTA CRUZ — Efforts to count the number of western monarch butterflies at overwintering locations across Santa Cruz and the California coast are in full swing and while experts say the midseason returns are encouraging, they caution of a concerning long-term trend.
Sunday will mark the final day of a three-week Thanksgiving monarch count organized by the Xerces Society – a nonprofit that has led invertebrate conservation efforts across the U.S. for more than 50 years.
According to a Xerces release, volunteer monitors in Santa Cruz reported 7,500 western monarchs at Natural Bridges as of Nov. 15 and 2,000 at Lighthouse Field – two of the county’s most frequented locations during the wintering season, which lasts from about October to March.
Neighboring areas in Pacific Grove and Pismo Beach saw totals of 12,328 and 24,058, respectively.
Overall, 105,000 monarchs had been reported across more than 70 sites across the state. Xerces estimates that when the Thanksgiving count is complete, more than 200 overwintering locations will be surveyed from Mendocino to San Diego and the reported totals will significantly increase.
“This Thanksgiving count is our single data point that is the best data point to compare over time when we think about trends in the population and the number of monarchs overwintering in the west,” Xerces Senior Endangered Species Conservation Biologist Emma Pelton told the Sentinel. “We’re in our 26th year of it as an organized count and it is the single best metric.”
The effort is powered by hundreds of community volunteers and is followed by a New Year’s count stretching from Dec. 24 to Jan. 8.
The outlook
Pelton said this season’s initial numbers are encouraging but come after a tumultuous few years for the fluttering orange and black insect.
According to Xerces data, about 200,000 monarchs were reported in the 2017 Thanksgiving count, before numbers dropped significantly in 2018 and 2019. By 2020, fewer than 2,000 were observed and some scientists feared the worst had already begun.
“It made a lot of people start to really worry that we had seen collapse,” Pelton said.
But in a somewhat relieving turn of events, the numbers bounced back in 2021 and almost 250,000 were documented.
While Pelton said the more than 105,000 reported so far is indicative of a “relatively good year,” extra emphasis was put on the word “relatively.”
When Thanksgiving count data collection began in 1997, more than 1.2 million western monarchs were reported. According to the Xerces website, the overwintering population has declined by roughly 95% since the 1980s.
“We want to celebrate the fact that they’re not at 2,000 or 30,000. We are seeing much better numbers. But let’s not lose that memory that we should be seeing much higher numbers,” Pelton said.
The why
So how did the mesmerizing creature beloved by so many in Santa Cruz finds itself in this precarious position? Pelton says that question is at the center of an active but healthy area of academic research and the leading causes are still somewhat open to debate.
Still, she said there are certain adverse factors across the state that have been identified including drought, human development, pesticide use and the slashing of non-native eucalyptus trees — which are often identified as fire risks, but are also the preferred clustering location for many monarchs.
The ubiquitous impact of climate change was also cited by Pelton, though primarily as something that exacerbates the problem as opposed to acting as a primary cause.
The general population of migratory monarchs was also put on the so-called “red list” for threatened species for the first time this summer.
But when Pelton sees the attention monarchs are now receiving across the country, the many successful habitat restoration efforts and the hundreds of dedicated community scientists – including many Santa Cruz – that volunteer every year, she feels some hope.
“We’re seeing the needle move,” Pelton said, “we’re all just hoping it’s enough and it’s fast enough and those are to be determined.”
The Xerces Society is expecting to have collected and processed the data from its two overwintering counts this season by the end of January. Information can be found at westernmonarchcount.org.
Source: Santa Cruz Sentinel