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Please could you explain how the numbers from the Xerces society were misinterpreted?
by goosegoose 4y ago
Please could you explain how the numbers from the Xerces society were misinterpreted?
- throwaway5752 4y agoI think the IUCN figure, comparing 10s of millions in the 1980s to 1,914 in the Xerces count, is apples to oranges. Xerces count started in 1997, and is great data but is a volunteer based effort in specific times and places. As far as I can tell it's not a population estimate. The 10s of millions appears to come from https://www.sciencedirect.com/science/article/abs/pii/S0006320717304809 https://www.sciencedirect.com/science/article/abs/pii/S00063... (via https://xerces.org/press/monarch-butterflies-disappearing-from-western-north-america https://xerces.org/press/monarch-butterflies-disappearing-fr...) This isn't a gotcha. The 72% risk of western monarch extinction within 20 years figure sounds right, if not conservative, per the paper. They just can't directly compare an estimated population with an exact count from a sampling. Please let me know if you know otherwise, I'm just an interested person on the internet