Using GPS technology and camera traps, biologists were thrilled to find rare litters of ocelot kittens and a den site—the first found for the small wild cats in a South Texas refuge in nearly two decades.

Hilary Swarts, a wildlife biologist for the U.S. Fish and Wildlife Service, says the kittens were spotted in April at two separate locations, though the news was released just last week.

The researchers detected four ocelot kittens on the Yturria Conservation Easement, a swath of privately owned ranch land that is protected in perpetuity as a home for wildlife.

“[At the easement], we detected three moms with litters, and one of those moms had twins, which is not typical and was incredibly exciting for us,”