Corridors that allow animals to move to more hospitable landscapes are essential to their survival in a changing climate, according to a new paper published this week in the journal Science. 

To arrive at that conclusion, researchers combined Indigenous and Western scientific methods — including ancient DNA and stable isotope analysis — to examine a global collection of fossilized horse bones that included specimens from Beringia, a region that once connected Alaska, the Yukon and northeastern Asia. The researchers wanted to understand how climate shifts during the last ice age impacted horse movement and survival.

Horses originated in North America about 4 million years ago and crossed into Asia via the Bering Land Bridge when sea levels were lower. Researchers traced the animals’ evolutionary lineages by analyzing the remains from horses ranging from a few centuries to a million years old. 

They found that horses migrated back and forth between the continents many times in response to changes in climate, with some migrations as recent as the last glacial period, which was 50,000 to 19,000 years ago.

The team also analyzed samples from horses that lived in the Yukon during the post-glacial warming period, when melting ice sheets submerged the land bridge and transformed the landscape from dry grasslands to boreal forests and swamps. The new conditions were less hospitable to grazing animals like horses, and they couldn’t migrate to more favorable locations. That led to a sharp decline in their population.

The authors say their findings underscore the importance of maintaining ecological corridors that allow animals to move between regions and habitats. They noted that such pathways appear essential for preserving biodiversity — not only in the rapidly warming Arctic, but globally.

The study was conducted by a team of 57 international researchers, including 18 Indigenous scientists and six researchers from the University of Alaska Fairbanks. The lead author was Yvette Running Horse Collin, a Lakota scientist and director of Taku Skan Skan Wasakliyapi: Global Institute for Traditional Science. 

UAF co-authors include:

• Patrick Druckenmiller, director, University of Alaska Museum of the North
• Pam Groves, research scientist, Institute of Arctic Biology
• Michael Koskey, associate professor, Center for Cross-Cultural Studies
• Dan Mann, research professor, Institute of Arctic Biology
• Sean Asikluk Topkok, director, Center for Cross-Cultural Studies
• Matthew Wooller, director, Alaska Stable Isotope Facility

ADDITIONAL RESOURCES: “Sustainability insights from late Pleistocene climate change and horse migration patterns,” Science

  america, bering, horses, landbridge