Wild horses chase a 3-year-old colt out of the band. He’s mature enough to compete for female attention so he’s no longer welcome.

Wild horse advocates are challenging the Bureau of Land Management’s plan to round up mustangs and burros in Southeast Oregon.

The BLM is planning to remove more than 1,400 wild horses in an area called Beatys Butte. The agency says the herd is six times larger than it should be. Fewer than 100 horses will be allowed to stay in the area.

Marika Ruppe represents the American Wild Horse Preservation Campaign. The advocacy group delivered a petition to the BLM protesting the roundup.

“The horses are federally protected. And those lands are designated to those horses, the herd management areas. So we feel those horses should stay,” said Ruppe.

Advocates say they’d rather the BLM focus on birth control for the herd to prevent further population growth.

The BLM says the horses that are removed will be made available for adoption or put in a permanent holding facility.

Watch Oregon Field’s Guide Special, “Wild Horses In Crisis”: