Historically, abundances of migratory birds have been estimated by skilled pilots and observers in fixed-wing aircraft who identify and count birds using ocular estimation techniques. However, the number of skilled pilots/observers is limited, and the USFWS needs to explore cost-effective and safe alternatives to assess the status of migratory birds. The use of small unmanned aircraft systems (sUAS) was explored as an alternative.
A crew of USGS and USFWS personnel conducted a night survey of cranes at primary roosting sites of the Monte Vista National Wildlife Refuge on March 21, 2012. A Raven® RQ-11 (A) sUAS was flown over roost areas at an altitude of 300 feet above ground level with a thermal Infrared NADIR camera along transects spaced 150 feet apart. The resulting videography was subsequently processed at the USGS offices in Lakewood, Colorado, and a total of 14,658 cranes were counted. More information on the project is available at the USGS Web site.
Cranes (red dots) on roost identified by enhancing sUAS thermal video imagery