Alabama biologists have found two endangered species of darters living in the same creek near Pinson Valley, and they did so with a little help from a camera-toting robot in the sky.

Samford University biology professor emeritus Mike Howell and others found both the rush darter and the watercress darter in a survey of Cunningham Creek, just off of Pinson Valley Parkway.

Before this find, the rush darter had only been documented in three spring-fed creeks, all in the Birmingham area. The watercress darter had only been found in four creeks naturally, although an introduced population seems to be doing well in a fifth.

This is the first time the two species have ever been found together in the same creek, and it likely would not have happened without help of an unmanned aerial vehicle.

Howell had gotten a report a watercress darter -- a species that he helped discover as an undergraduate -- had been spotted in the creek. The problem was that Howell couldn't tell where the stream went after it disappeared underground.

So Howell enlisted the help of Dr. David Aarons, a former biology student of his who is now a medical doctor and a licensed drone pilot. With his drone, Aarons was able to locate the creek as it emerged from under a set of railroad tracks. Aarons and Howell, with the assistance of Dan Drennen of the U.S. Fish and Wildlife Service, picked out a good sampling location with darter-friendly conditions that they could access without entering private property.

The group started netting in search of the watercress darter, but their first successful catch turned out to be something wholly unexpected.

"We were just surprised out of our gourds because it was a rush darter," Howell said.

On that trip and others, Howell said the group found seven or eight rush darters and 15 watercress darters in the creek.

"To find two endangered species within several hundred yards of each other is really pretty amazing," Howell said. "They're not abundant, but they are there."

Howell said the land where the fishes were found is still there partly because it is swampy enough that it wasn't very attractive to developers. The findings have been submitted to the Alabama Academy of Sciences where it is awaiting peer review before publication.

Aarons has used his drones to help with other research projects, performing aerial surveys of Birmingham's Five Mile Creek and working with John Manion of the Birmingham Botanical Gardens to look for rare plants at Almond Rock near the Talladega National Forest.

Two of the biggest advantages of using unmanned aerial vehicles for science are relative low cost, and the ability to go places boats, airplanes and humans can't easily reach.

"It's great, especially if you can't afford to pay $500 an hour for a helicopter," Aarons said. "Plus, with the drones you can fly basically right down to the water's surface, or to the tops of the plants you're trying to survey."

Nationwide, scientists are increasingly using the UAVs to break new ground to observe species, track poachers and even collect whale snot.

"I think the drone is going to be a great tool for field biologists in the future," Howell said. "If it hadn't been for the drone, these darters never would have been discovered."

You can watch some of the Aarons' footage of Cunningham Creek in the video above.