A New Mexico State University scientist has a high-flying plan to monitor his salt cedar plots along the Pecos River using remote-controlled digital cameras on a kite.
Now entomologist Dave Thompson has an aerial view of how effective tiny leaf beetles are against water-guzzling salt cedars. The beetles, which feed on salt cedar leaves, have been used successfully against the invasive trees in several other states.
The kite’s perspective is perfect for showing large-scale changes, Thompson said, from the NMSU Las Cruces campus. “It’s already obvious that this is going to be an important new documentation tool,” he said. “We can do any number of tests on the ground, but a before-and-after picture is an outstanding way to show plot changes over time.”
Most of his photos are taken from a few hundred feet off the ground. The kite can go much higher, but federal regulations require filing a flight plan if the kite is going above 500 feet.
“It’s a lot of work to reel that kite in and out,” Thompson said. “But once it’s up, we can take more than 300 pictures in 30 minutes. After we’ve filled up a memory card, we bring the kite down and download the pictures to a laptop computer to see what we’ve got. If we don’t have exactly what we want, then we’re back in the air.”
The NMSU scientist is studying the effectiveness of using a leaf beetle, which is about the size of a pencil eraser, to control salt cedar, one of New Mexico’s most troublesome invasive tree species. Last fall, about 600 of the leaf beetles were released along the Pecos River near Artesia as part of a large-scale test to track beetle populations and their effect on the water-gulping salt cedar.
Thompson’s basic equipment includes a lightweight, 4-megapixel digital camera, a specially made equipment cradle and two kites – all for about $1,200. Normally, a two-person team is needed to get the kite and camera safely into the air. The entire system sets up in less than 30 minutes and can be stored in the trunk of a car.
Thompson uses two kites in his research: a 7-foot by 5-foot Rokkaku kite that operates in winds up to 10 miles per hour, and a bag kite for higher winds. Thompson hand-built a special reel to bring the kite and camera down gently. The reel, which has internal brakes like a fishing reel, holds 1,000 feet of 1/8 inch-thick nylon rope.
California’s Brooks Leffler, an aerial kite photography pioneer, specially made the custom camera cradle for Thompson. The cradle and camera, which weigh about 2 pounds, feature a radio-controlled guidance system that allows the camera to pivot 360 degrees. The self-leveling camera platform sits about 100 feet below the kite when aloft.
“I never knew there were so many kite designs,” Thompson said. “It turns out that they’re all related to wind conditions. You really have to understand the wind.”
He admitted to several Charlie Brown moments while perfecting his kite-flying technique. The team practiced and crashed a few times with 2 pounds of soda bottles before safely launching their electronic equipment.