Surprisingly few basic tools are available to protect wildlife. The two most vital ones are “ark” and “park.” 
The “ark” method relies on bringing animals from other strongholds into areas where they have disappeared. This often means translocating or captive breeding to restore populations of imperiled animals back into nature, much like the U.S. achieved by moving wolves from Canada into the northern Rockies in the mid 1990’s. In contrast, the “park” method uses land conservation to serve as a protected home in which restored and other wildlife species can thrive, much like Yellowstone National Park functioned as a haven for this wolf recovery.
Parks, reserves, and other protected areas are a fundamental strategy used throughout the world for conserving wildlife today. These protected areas usually limit or even forbid human access so that the landscape remains untouched and wildlife species have a better chance to make it on their own. But are parks actually getting the job done? And if so, how and when are they successful?
Keeping Humans Out Can Work – or Backfire
Without a doubt, protected areas that keep humans out can work big time. Sometimes the most dramatic evidence for that success is purely accidental. Thirty years ago, all humans had to evacuate an area the size of Rhode Island around the Chernobyl nuclear plant in Ukraine due to the radioactive contamination. But today, nature has so reclaimed this environment that a ‘wonderland’ now provides sanctuary for some of Europe’s largest and scarcest mammal species.  Photos and aerial fly-overs reveal flourishing animal populations, including such icons as gray wolves, moose, European bison, deer, wild boars, red foxes, and raccoon dogs. Several species are widely distributed across Chernobyl, and some occur even where contamination is high.
But a ‘lock it and leave it’ approach does not always work, and the reasons can vary. In Sweden, national parks ironically serve as refuges for the illegal killing of large carnivores.  Inside three large Swedish national parks, several large carnivores all suffered a higher risk of being poached inside the protected area than in nearby, unprotected areas. It turned out that law enforcement inside those large and remote parks was too lax to stop the persecution of brown bears, Eurasian lynx, and wolverines. Setting aside large amounts of land and managing it only passively wasn’t enough to protect large predators.
What Lives in the Park Doesn’t Necessarily Stay in the Park
Our desire to see large carnivores in their native habitats is a fundamental reason for the ecotourism in many national parks around the globe. A recent study, however, showed that in two U.S. national parks (Denali and Yellowstone), legal wolf hunting just outside park boundaries reduced later sightings of gray wolves inside the parks.  Wolf sightings in Yellowstone National Park increased 45% in years when no wolves from packs along the park’s boundaries were killed. Sightings in Denali National Park were more than twice as likely in years when the park instituted a no-hunting buffer zone next to the protected area.
Killing of carnivores outside parks substantially reduces the potential for wildlife-viewing enjoyment inside these protected areas. Concern for such lost opportunity lay behind the international outcry over Cecil the lion’s death by a trophy hunter in Zimbabwe’s Hwange National Park. Without suitable buffers around parks, even large core protected areas are simply not enough.
Economic Incentives Can Be a Win for Habitat and Humans
In China, one of the most biologically diverse but also densely populated countries in the world, keeping people out of parks with a “fences and fines” model would normally carry negative consequences for the livelihoods of people living nearby. Unlike most national parks in the U.S., however, entire towns can exist inside China’s parks. Economic incentives pay nearby residents for sustainable forest uses, and to report any illegal activities. As a result, habitat quality for pandas inside the park has actually improved. And paying individual households to act as ‘rangers’ was 2.5 times more effective than paying local governments! 
Given enough flexibility and a willingness to learn, then, parks are indispensable as a strategy to conserve wildlife. And if we can factor in human nature and wildlife needs alike, parks will function even better. Then everyone wins: us, the wildlife, and the protected areas that sustain it all.
1. Dolman, P.M., N.J. Collar, K.M. Scotland, and R. Burnside. 2015. Ark or park: the need to predict relative effectiveness of ex situ and in situ conservation before attempting captive breeding. Journal of Applied Ecology 52: 841‒850.
2. Brulliard, K. 2016. 30 years after Chernobyl disaster, camera study captures a wildlife wonderland. https://www.washingtonpost.com/news/animalia/wp/2016/04/26/30-years-after-chernobyl-disaster-camera-study-captures-a-wildlife-wonderland/ (accessed 3 June 2016).
3. Rauset, G.R., H. Andrén, J.E. Swenson, G. Samelius, P. Segerström, A. Zedrosser, and J. Persson. 2016. National parks in northern Sweden s refuges for illegal killing of large carnivores. Conservation Letters.
4. Borg, B.L., S.M. Arthur, N.A. Bromen, K.A. Cassidy, R. McIntyre, D.W. Smith, and L.R. Prugh. 2016. Implications of harvest on the boundaries of protected areas for large carnivore viewing opportunities. PloS One 11: e0153808.