Butterflies Are in Dramatic Decline Across North America. A Close Look at the Western Monarch Shows Why Pesticides, habitat loss and climate change have taken their toll on the beloved insects. But the experts working with them still find hope for their future April 24, 2026 11:42 a.m. Western monarch butterflies bask in the sun on a eucalyptus branch at Lighthouse Field State Beach. In December 2025, researchers placed ultralight radio tags on some monarchs at this site, hoping to track their movements and identify areas to prioritize for the species’ conservation. Darren Orf On a misty Friday morning in November, with dawn’s last warm hues clinging to the gloomy clouds above, the Pacific Grove Monarch Sanctuary is whisper quiet. Even the persistent roar of the ocean, only a few minutes’ walk from this small copse among single-family homes, is deadened by walls of eucalyptus and Monterey cypress.…