Halloween Trick: Technology Reveals Airborne Creatures of the Night


Researchers are using sophisticated technology like Doppler weather radar to study the aerosphere — the air and the organisms that migrate and feed within it.

“The air is full of life, often unnoticed,” said Elizabeth Blood, program director in the National Science Foundation’s Division of Biological Infrastructure, which funds the research. “The skies hold secrets about animals that live at least part of their lives there. Research in aeroecology is opening a window into this unseen world.”

Thermal infrared image of flying Brazilian free-tailed bats in Texas by Thomas Kunz, Boston University

Biologists and atmospheric scientists engaged in aeroecology study how and why airborne organisms — bats, birds, arthropods and microbes — depend on the support of the atmosphere closest to Earth’s surface.

aeroecology2.jpgAeroecology integrates atmospheric science, earth science, geography, ecology, computer science, computational biology and engineering.

In contrast to animals with a strictly terrestrial or aquatic existence, says aeroecologist Thomas Kunz of Boston University, those that routinely use the aerosphere are immediately influenced by changing atmospheric conditions like winds, precipitation, air temperature, sunlight — and moonlight.

Brazilian free-tailed bats on Doppler radar images by Thomas Kunz, Boston University

Information in the aerosphere, scientists are finding, can help us understand how animals respond to altered landscapes and atmospheric conditions.

Thermal imaging cameras, which record temperature profiles of animals usually invisible at night, allow biologists to count numbers of animals like Brazilian free-tailed bats.

“Using NEXRAD Doppler weather radar, we can distinguish the movements of birds vs. bats, based on their patterns of daily and nightly dispersal,” Kunz said. “With NEXRAD radar, we can also identify and document the movements of animals during migration.”

Organisms that use the aerosphere, like birds and bats, are influenced by an increasing number of man-made conditions and structures: lighted towns and cities, air pollution, skyscrapers, aircraft, radio and television towers, and communication towers and wind turbines.

“In addition, human-altered landscapes are affected by deforestation, intensive agriculture, urbanization and industrial activities,” Kunz said . “These factors are rapidly and irreversibly transforming the habitats upon which airborne organisms rely.”

More from National Geographic News:

Hi-Tech Bat Detector Sheds Light on Shadowy Species

Bat Patrol from National Geographic Magazine

(includes multimedia demonstration of bat-tracking radar)

Changing Planet

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