Monday, November 2, 2020

November 2020 Science Article Summary


Happy post-Halloween!

This month I have five big global conservation papers, plus two on wildlife migrations. Also - my team is hiring! You can find out more and apply here: and let me know if you have any questions.

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Dinerstein et al. 2020 is the latest paper advocating for conserving half of the earth (not all via legal protection). I like that they break down the primary conservation focus of each new area: rare species, distinct species assemblages (beta diversity), intact large mammal populations ('rare phenomena'), intact habitats (driven mostly by the Last of the Wild data which tends to rate rural farms as relatively intact), and high carbon stocks (see Figure 1 for a global map). Interestingly the big mammal cluster is 42% the size of current protected areas but stores 91% as much carbon. There's also a useful connectivity analysis: they find 4.3% of global land area would be needed to connect current protected areas (w/ ~3.5km wide corridors), and if their 50% target was met we'd still need 2.7% more to provide connectivity. About a third of targeted lands are indigenous territories which may already be effectively conserved in some cases. As a reminder, the 50% global target was picked arbitrarily, so describing these as 'science-based targets' is a bit misleading. They used science to identify places that add up to 50%, but the 50% overall target is NOT science-based. Check out their results at

Maxwell et al. 2020 reviews how effective the last 10 years of new protected areas (PAs) have been in covering underprotected species and areas. The key finding is that PAs are not being added in the highest priority areas, and while some species are doing better than average in new protection, protection overall remains badly inadequate relative to the needs of species and ecosystems. On land PAs expanded by ~9% but only contributed to very small increases in representation (only increases in wilderness were significantly better than that 9%, while carbon and terrestrial key biodiversity areas expanded less than 9%, Fig 3b). At sea PAs more than doubled in area (+160%), with corals, cartilaginous fishes (like sharks), marine wilderness, and pelagic (open ocean) areas doing even better than that. But the expansion of marine PAs underperformed in increasing representation of marine reptiles & mammals, bony fishes, key biodiversity areas, and several others. The authors call for more transparency around decisions to add or expand (or shrink) PAs, improved recognition and management of Other Effective area-based Conservation Measures, better planning for climate change, more financing for protection and management, and more.

Strassburg et al. 2020 is a global prioritization of where to restore ecosystems on land. As with similar analyses they find we could achieve more at lower cost if we use analyses like theirs to drive the work. Fig 3 has the best comparison of cost and environmental benefits, while Fig 1 has maps of priority areas. However,  Maxwell et al. 2020 is a reminder that these decisions are NOT typically driven like papers like this, and Fig 1e raises immediate concerns about the likelihood of proposing to restore most of the Philippines and Indonesia, or 96% of converted habitat in the Caribbean. Scenario VI in Fig 3 shows how much lower the environmental benefits are (and that the cost is higher) if each country restores their highest priority 15% of lands relative to what's possible by concentrating restoration in relatively few countries (scenarios I-III). Despite the challenges, this paper does make a key point: given the relatively high cost of restoration relative to protecting intact habitat, it's important that we stretch those dollars by picking the right places to restore (including likelihood that restored lands won't get quickly reconverted).

The 5th Global Biodiversity Outlook report has mostly bad news - none of the 20 targets set in 2010 for 2020 have been met, although 6/20 have been partially achieved. Check out page 6 of the summary for policymakers for the results (green means met, yellow some progress, red no progress, and purple negative progress). Some of these are optimistic, e.g., it's very optimistic to assume that not only will 10% of the ocean be protected this year but that they will focus on areas of particular importance for biodiversity and ecosystem services. But you can read more about why they rated it this way on page 82 of the full report. It's worth at least looking at the high level scores for everything, and digging into the ones most relevant to your work.

van Rees et al. 2020 has 14 recommendations to improve freshwater outcomes in  the next version of the Convention on Biological Diversity (CBD) as well as the EU's biodiversity strategy. In brief, they are: don't lump freshwater in w/ lands and ocean when planning, recognize their role in supporting human life, recognize the importance of connectivity and barriers (like dams), manage freshwater ecosystems at the watershed / catchment scale, use systems thinking to consider trade-offs like how hydropower or intensive ag impacts on freshwater systems compared to others, improve existing freshwater protected areas (via restoration, management, and enforcement), use 'flagship umbrella species' to get freshwater biodiversity more attention, do more research on invasive species and how they impact freshwater ecosystems, improve monitoring of freshwater ecosystems, improve freshwater data's accessibility, use novel methods to monitor biodiversity like environmental DNA (eDNA) or digital text analysis, use strategic spatial planning, use more global data (like Red-Listed species) in national and local decision-making, and seek to better integrate top-down decision making by experts (due to technical complexity) with bottom-up stakeholder-driven approaches.

Greggor et al. 2020 argues that for conservation interventions to influence wildlife, it can help to think through the lens of animal cognition. It seems funny, but check out Fig 3 on “Why did (or didn’t) the chicken cross the road?” – they ask a really useful set of questions (like does the chicken see habitat on the other side and perceive it as better, does it see the road and see it as a danger, are danger cues masked, does it see the overpass and perceive it as safer, etc.). Fig 2 offers a decision tree to pick the right intervention, and the paper proceeds to offer several rules about how animal cognition and decision making tends to work to explain those recommendations. They note some limits, like omitting how animals deal w/ novelty, and how much is unknown about perception in many species.

Testud et al. 2020 evaluated crossings of amphibians (newts, frogs, toads, & salamanders) in tunnels under high-speed rail. Shorter tunnels led to more successful (complete) crossings for most species (but not toads), and broadcasting audio of frog mating calls led to a big increase in successful crossings (and crossing speed) for the one frog species who was included in the recordings. It would be interesting to follow up to see if more complex audio representing more species would work better, and even whether this approach might work for mammals as well.

Dinerstein, E., Joshi, A. R., Vynne, C., Lee, A. T. L., Pharand-Deschênes, F., França, M., … Olson, D. (2020). A “Global Safety Net” to reverse biodiversity loss and stabilize Earth’s climate. Science Advances, 6(36), eabb2824.

Greggor, A. L., Berger-Tal, O., & Blumstein, D. T. (2020). The Rules of Attraction: The Necessary Role of Animal Cognition in Explaining Conservation Failures and Successes. Annual Review of Ecology, Evolution, and Systematics, 51(1), annurev-ecolsys-011720-103212.

Maxwell, S. L., Cazalis, V., Dudley, N., Hoffmann, M., Rodrigues, A. S. L., Stolton, S., … Watson, J. E. M. (2020). Area-based conservation in the twenty-first century. Nature, 586(7828), 217–227.

Secretariat of the Convention on Biological Diversity. (2020). Global Biodiversity Outlook 5. Montreal, 208 pages. Available at

Strassburg, B. B. N., Iribarrem, A., Beyer, H. L., Cordeiro, C. L., Crouzeilles, R., Jakovac, C. C., … Visconti, P. (2020). Global priority areas for ecosystem restoration. Nature, (August 2019).

Testud, G., Fauconnier, C., Labarraque, D., Lengagne, T., Lepetitcorps, Q., Picard, D., & Miaud, C. (2020). Acoustic enrichment in wildlife passages under railways improves their use by amphibians. Global Ecology and Conservation, e01252.

van Rees, C. B., Waylen, K. A., Schmidt‐Kloiber, A., Thackeray, S. J., Kalinkat, G., Martens, K., … Jähnig, S. C. (2020). Safeguarding freshwater life beyond 2020: Recommendations for the new global biodiversity framework from the European experience. Conservation Letters, (April), 1–17.