A troubling trend sees a 97% decline in monarch butterflies

https://www.theguardian.com/us-news/2018/dec/07/its-a-sad-reality-a-troubling-trend-sees-a-97-decline-in-monarch-butterflies

Gabrielle Canon in Santa Cruz
Sat 8 Dec 2018 01.00 EST

In the 1980s, roughly 4.5 million monarchs wintered in California, but at last count, there may be as few as 30,000

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Just two years ago, 8,000 overwintered here, but these days, just more than a thousand are fluttering amidst the Santa Cruz trees. It’s part of a troubling trend: over the last two decades monarch numbers in the West have declined by roughly 97%.

“It is a sad reality of climate change,” said Anthony Dutierrez, a volunteer guide at the park and biology student at the University of California, Santa Cruz, as he takes a break from guiding school children through a tour. “For every little thing that changes there’s not just one consequence – it’s a whole chain reaction.”

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While researchers can’t pinpoint the direct cause for each annual decline, there are several factors cited for the overall loss in numbers. For years, western monarchs have faced habitat loss in both the places they breed and where they spend their winters and increased use of pesticides has also taken a toll. Climate change, of course, has also played a role. Both drought and severe weather are deadly stressors for the butterflies, that are already under siege.

Monarchs aren’t alone. As the New York Times noted in a recent article on the “insect apocalypse,” researchers in Germany found flying insect populations there had decreased by up to 82% over the last three decades. A collection of separate studies showed that the populations of most of the insect species included, had been nearly cut in half. The indirect effects of this massive disappearance – considered as part of the sixth extinction – are still unknown, as is the scale of just how massive this die-off might be. Most insect populations aren’t closely watched.

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For now, researchers will be looking to next year’s numbers to see if the efforts can help turn the decline around. It is still possible for the butterflies to bounce back.

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