Mountain lions become isolated in California after tracking study

A GPS-collar study of 87 subadult mountain lions in California found that roads and development limit young adults' movements, increasing population isolation and reducing genetic diversity.

Researchers published a study in Frontiers in Ecology and the Environment that tracked 87 one- to three-year-old "subadult" mountain lions in California using GPS collars. The tracking showed that roads, buildings and other human infrastructure often prevent these young adults from traveling long distances to new breeding ranges. As a result, some populations have become isolated and show signs of reduced genetic diversity. The lead author, Kyle Dougherty, said disrupted connectivity can lead to population decline. Key findings: - The study tracked 87 one- to three-year-old mountain lions with GPS collars to map movement patterns. - Roads and development frequently blocked long-distance movements by young adults, limiting gene flow between populations. - Researchers reported increasing isolation and reduced genetic diversity in some populations, including those nearest Los Angeles. - The team noted that mountain lions sometimes use small patches of forest or shrubs to move and highlighted wildlife corridor crossings as important for connectivity. Summary: Human infrastructure appears to be reducing connectivity among California mountain lion populations, with potential effects on genetic diversity and population stability. Researchers are using the movement data to identify likely locations for wildlife corridor crossings and to guide additional research.