Conservationists in the UK recently released a pair of beavers in England’s South Downs National Park to help revitalize an area of critical wetlands. The release of the beavers — named Willow and Wilson — marks the native species’ return to the area after a 600-year absence.

According to a BBC report, beavers were hunted to extinction in the area in the 16th century due to demand for their meat, fur, and scent glands. Now, scientists hope returning the species to South Downs National Park can help support the local ecosystem by improving the quality and quantity of the wetlands.

The Natural Resources Defense Council reports that beavers play a critical role in maintaining healthy wetland habitats. Beavers are known for their dam-building behaviors, which help create and preserve wetlands. The NRDC calls beavers “ecosystem engineers,” explaining the species directly influences resource availability for other species by reshaping their physical environment.