GIBBON — So what are UV light system observers looking at each night while sitting in blinds near two power lines that span the Platte River’s main channel on either side of Rowe Sanctuary’s visitors center?
“You’re looking at cranes as they approach individually or as a group,” said Rowe Sanctuary Conservation Program Associate Amanda Hegg. “You’re looking for any reaction (to the power lines).”
One person uses binoculars and a night vision scope to make and call out observations. The teammate writes the information on a data sheet, including details about the cranes’ height from the river and proximity to the power lines.
Hegg and Rowe Sanctuary Conservation Program Manager Cody Wagner listed some terms they and other observers use to describe crane behaviors.
“Climbing” is when cranes go up and over the power lines.
“Flare” is the word when cranes seem to see the lines at the last minute and then go over, under or through them.
“Reverse” tells the data recorder that cranes saw the power lines from a distance and turned around.
“Sometimes cranes don’t acknowledge the power lines at all” when going over or under them, Hegg said. “That’s a very dangerous flight.”
She and Wagner said their observation skills have improved during the past five weeks through practice and becoming familiar with landmarks that help them to judge space and distance.
Wagner said they focus on an imaginary box around a power line that is 50 meters on either side and 35 meters above. The width is the entire span of the line.
“When cranes are doing multiple things, we record the most risky reactions,” Hegg said. “... Collisions are the main thing we’re interested in here.”
Details noted about collisions include how far the crane was along the power line, which line was struck and what happened. Did it fall or fly on? If it fell, how did it fall?
Wagner said they also record environmental conditions such as weather and moon phases each night. Those details also will help researchers determine the effectiveness of UV lights in helping cranes avoid collisions with the power lines.