Linking national parks could help mammals survive

Although national parks are the backbone of conservation efforts, mounting evidence suggests that many parks are too small to sustain long-term viable populations and maintain essential, large-scale ecological processes, such as large mammal migrations and natural disturbance regimes. 

Now, a study published in the journal Nature Scientific Reports has found that enhancing ecological connectivity through so-called “corridors” or “linkages” among some of the oldest and largest national parks in Western U.S. and Canada would significantly extend the time that many mammal species populations can persist, while also allowing species to shift their geographic ranges more readily in response to climate change.

The experts investigated the value of establishing ecological corridors for large mammals between the Yellowstone and Glacier National Parks, and between Mount Rainier and North Cascades National Parks. The analysis revealed that linking these parks would increase the long-term persistence time of mammals by a factor of 4.3 compared to the persistence time in fragmented, individual parks.

“Eliminating barriers of movement between parks and more carefully managing land-use along these pathways are crucial for the survival of many mammal species,” said study lead author William Newmark, a research curator at the Natural History Museum of Utah. “Establishing an expanded protected area network based on identified mammal pathways and incorporating adjacent wilderness areas would greatly enlarge available habitat for mammal species. And this would have a very positive effect on species persistence time.”

Since the corridor network that the researchers proposed would cross two- and four-lane highways, it would require multiple ecological bridges over and under these roadways. Fortunately, such over- and underpasses for wildlife are already in the process of being constructed in Western U.S. and Canada. “However, a much greater effort will certainly be required if we are to reduce the known adverse impacts of highways on species movement and dispersal,” said study co-author Paul Beier, a professor emeritus of Landscape Conservation at the Northern Arizona University. 

Although scientists have long known that ecological corridors enhance population persistence of species, most previous studies have been small-scale experiments. By analyzing the positive effects of large-scale conservation initiatives that aim to enhance ecological connectivity between protected areas in Western U.S. and Canada, the present study could serve as an important template for large-scale biodiversity conservation both nationally and worldwide.

“The analytical approach presented in this paper can provide conservation planners and practitioners with a powerful method of prioritizing and quantifying the value of ecological linkages between protected areas,” concluded study co-author John Halley, an expert in Biological Applications and Technology at the University of Ioannina in Greece.

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By Andrei Ionescu, Earth.com Staff Writer

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