Researchers have long assumed that habitat fragmentation contributes to extinction risk for animals, but until now, they have not been able to measure it for a major group of animals on a global scale. In a first-of-its-kind study, an international research team led by Colorado State University successfully measured habitat fragmentation for over 4,000 species of land-dwelling mammals. Among the findings, researchers discovered that species with more habitat fragmentation are at greater risk of extinction.