Video shows birds, bats and insects near solar project power towers

Reporter: Below are two short videos.

Video surveillance is the most effective method for detecting flying animals around solar power towers, according to a study by the U.S. Geological Survey and its partners using a variety of techniques at the Ivanpah Solar Electric Generating System facility in southeastern California.

The study is the first to examine a variety of remote sensing and sampling techniques to determine which might be most effective in monitoring the impacts of solar facilities on flying animals. This information will be used to further study the effects of solar infrastructure on flying animals (a poorly understood topic) and to develop methods to reduce harmful impacts.

At Ivanpah, evidence has been observed of flying animals being affected by the high temperatures near the solar tower. The new study shows that while birds and bats have occasionally been seen near Ivanpah, most observations involve insects.

Camera technology helped detect animals flying near the solar tower, differentiate birds and bats from insects, and observe the numbers and behavior of these animals. Hundreds of hours of video surveillance footage helped determine that most of the small, smoking objects observed in the solar flux field were insects. While the study did not quantify the impact, fewer than 15 birds were observed to be affected by solar flux in more than 700 hours of video.

“Our goal with this pilot study was to evaluate several monitoring methods, determine their strengths and limitations, and assess their suitability for future use in studying the potential impacts of solar towers on flying animals,” said Robb Diehl, a research ecologist with the U.S. Geological Survey and lead author of the study.

For the study, scientists worked at the Ivanpah facility for several weeks in May and September 2014, documenting periods of migration and seasonal abundance of birds, insects and bats. They used a combination of radar, videography and insect sampling to detect and observe the presence, diversity, movements and behavior of animals during both daytime and nighttime near the operating solar tower.

The facility is the world’s largest solar project, and uses large areas of mirrors to reflect and concentrate sunlight onto solar receivers atop 450-foot-tall towers. During operation, a highly concentrated area of ​​sunlight, called the solar flux, fills the airspace around these tower receivers. Flying animals that enter this solar flux can experience intense heating enough to cause injury or death.

Scientists used a combination of radar, video and insect sampling to detect and observe the presence, diversity, movements and behavior of birds, bats and insects near solar towers during the day and at night.

The all-weather radar recorded more than a million tracks of birds, bats and large insects such as dragonflies, and the intensity and timing of the movements varied throughout the study period.

Scientists use insect traps to catch insects flying at altitudes of nearly 10 feet. The number and type of insects caught vary depending on the location of the traps, time of day, and season.

“While radar provides useful information about animal activity throughout the facility, the camera approach shows the greatest potential for directly observing and identifying animals flying in the solar flux,” said Paul Klein, a research biologist with the U.S. Geological Survey and co-author of the study.

Broader research could test the usefulness of these technologies to automatically detect and observe flying animals near solar towers to deepen understanding of their impacts on wildlife.

This article”Evaluating the effectiveness of wildlife detection and observation technologies at solar power tower facilities” Published in a scientific journal PLOS ONE.

For more information on using new radar technology for wildlife research, visit the U.S. Geological Survey Northern Rockies Science Center website.