For decades, scientists have alerted the public of this probable scenario, so it is unsurprising that the National Commission of Protected Natural Areas in Mexico — where the species' eastern population migrates for winter — announced earlier this week the species' lowest population on record.
Monarch populations are teetering on extinction, their numbers down to 5% of what they were a few decades ago. Here's what to know and the simplest way to help.
The number of western monarch butterflies overwintering in California dropped by 30% last year, likely due to how wet it was, researchers said Tuesday.