04/27/2009 AT 04:00 PM EDT
When they're full grown, they'll move faster than a speeding bullet. But for now, these 1-month-old twin Peninsular pronghorns are just enjoying their first steps and drinking plenty of milk so they can grow big and strong. Born March 30 at the Los Angeles Zoo, the brothers will grow to become among the second-fastest animals on Earth, next only to African cheetahs. Adult pronghorns can run up to 70 mph, traveling at speeds of 40 to 60 mph for 60 minutes at a time! Though the twins in Los Angeles are young, they began walking just 30 minutes after birth, and can already outrun humans.
The Los Angeles Zoo is currently the only U.S. institution to breed the endangered species – in fact, this is the second time in a year that Peninsular pronghorns have been welcomed at the facility. Native to Mexico, there are reportedly just 250 of the antelope-like creatures living in the wild.