My paper with @cagrainger and Nick Parker on the effects of #Wolves on deer-vehicle collisions (DVCs) is now out in PNAS! We find that wolves reduce the frequency of DVCs by a quarter, generating large economic benefits. Why is this important? /1 @PNASNews dx.doi.org/10.1073/pnas.2… 
The economic benefits conveyed by predators are often indirect, diffuse, and difficult to measure, whereas the costs of predators are salient and local. We provide a concrete estimate of the benefits of wolves to local communities though their control of deer populations. /2
Deer populations plummeted in the 19th century, but they are now overabundant in many parts of the USA. This overabundance causes damages to crops, forests, and landscaping. It likely also contributes to the spread of diseases like Lyme Disease and Chronic Wasting Disease. /3
More saliently, overabundant deer also contribute to rising deer-vehicle collisions (DVCs), which cause at least 29,000 human injuries, 200 human fatalities, and nearly $10 billion in total economic losses each year. DVCs are the largest known economic cost of deer. /4
We examine the relationship between wolf colonization and changes in DVCs in Wisconsin counties over 22 years. Using econometric techniques, we show that wolf presence leads to a 24% reduction in DVCs, on average, generating about $11 million per year in benefits statewide. /5
Most of the effect of wolves on DVCs (75%) occurs through changes in deer behavior, rather than reductions in deer populations. This suggests wolves control deer damages in ways that seasonal human deer hunters cannot, due to the limited duration of the hunting season. /6
Our findings should be good news for wildlife managers trying to balance the local costs and benefits of wolves. They do not have to choose between supporting wolves or the economically and culturally important recreational deer hunting industry. They can do both. /7
Our findings also show that the benefits from reduced DVCs can offset livestock losses, with DVC benefits 63 times the costs of verified livestock predation. But, it will be critical to find ways for those who benefit from wolves to compensate those who bear the costs. /8
Finally, our results suggest that wolves may be an unexpected solution to a tricky civil engineering problem, namely traditional DVC measures are expensive and difficult to scale beyond major DVC hotspots. Wolves seem to provide a cost-effective solution at a broad scale. /9
A full replication package for this study is at github.com/jennifer-rayno…. /10
We are also grateful for the fantastic press coverage of our paper! More to follow... /n
@larsonchristina @AP (picked up at over 150 outlets as of this afternoon!)
https://twitter.com/larsonchristina/status/1396979695787331589?s=20
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