Thread by @juliapgjones

Do protected areas effectively conserve species populations? Our paper out today in @Nature tries to answer this really important question.
nature.com/articles/s4158…

Our study makes use of the incredible data collected by 1000s of volunteers around the world who count birds regularly on their ‘patch’. This enormous effort is brought together by @WetlandsInt (@audubonsociety in the US).
nature.com/articles/s4158…

While there have been some great studies exploring impact of PAs on habitat (especially forest cover), few have looked at the impact on species. We explore how 1500 PAs have impacted 27,000 populations of waterbirds (mostly in N. America/Europe).
nature.com/articles/s4158…

We use a Before After Control Intervention framework to explore the impact of protection on populations. Exploring changes in trends in populations at sites before/after protection & in matched control sites. 📷Khalid Sharif.

So are protected areas working? Hmmm…. We have a superficially rather unsatisfying answer. The picture is mixed. Whether grouped by species or sites, you see a real mix of positive, negative & neutral impacts.
nature.com/articles/s4158…

This is rather disappointing, especially given world leaders are expected to gather soon at #COP15 to commit to expand the world’s PAs (30% by 2030). Do our results mean these efforts are misguided? (📷Matti-Saranpää)

We are NOT saying PAs don’t help waterbird species. But lines on maps don’t change management. The only covariate we found with a reliably positive association with ‘success’ was where we had some evidence a site is managed for waterbirds.
nature.com/articles/s4158…

For nerds: we include a comparison of what inference we would have drawn had we used a Before After OR a Control Intervention approach (not the full BACI). Extra support (as if needed!) that more robust approaches to estimate counterfactual are needed.
nature.com/articles/s4158…

The paper was brilliantly led by @hannahchoppie & included a whole dream team of coauthors including @jgeldmann @tatsuya_amano @ali__johnston @Bill_Sutherland @BennoSimmons & colleagues from @WetlandsInt
nature.com/articles/s4158…

Really nice coverage by @Vic_Gill of this paper. I really like the emphasis on the policy implications (though not sure about the title-the tricky thing is the result is mixed, not as strong as 'most do not benefit').
bbc.com/news/science-e…