New collar sensor could reveal how wildfire smoke affects animal health

When wildfire smoke fills the air, most people can go inside to avoid it. Wildlife does not have that option, and little is known about how animals living in remote areas respond to wildfires and smoke exposure.

Colorado State University researchers have developed an air quality monitoring device that can be paired with systems that track wildlife location and physiological data to learn how smoke affects wildlife health and behavior. The smoke logger is an open-source tool that will allow wildlife researchers everywhere to answer questions that previously couldn’t be answered and gather data that can be used to better protect wildlife.

The smoke logger design and programming are now freely available with publication of initial results in Methods in Ecology and Evolution.

“Wildfire is now a chronic problem in North America. We are all experiencing these massive smoke plumes that can negatively affect air quality for weeks at a time,” said CSU professor George Wittemyer, who led the project with U.S. Forest Service wildlife ecologist Mark Ditmer and CSU postdoctoral researcher Adam Parlin. “We’re interested in how wildlife adjusts its behavior relative to smoke exposure, and it wasn’t possible to know until now.”

As wildfires increase in frequency, size and severity, smoke plumes that affect air quality for an extended time are a new stressor for wildlife, Wittemyer added, and air quality typically is not monitored in wilderness areas. The small, affordable smoke logger the team has developed can be attached to animal-borne collars to record the concentration of hazardous particles animals are breathing.

Tracking smoke from wildlife’s perspective

“We know relatively little about the impacts of wildfire smoke on the behavior of animals in the field, especially how free-roaming wildlife respond to severe smoke events,” said Parlin, who designed the smoke logger while he was a postdoctoral researcher in the Department of Fish, Wildlife and Conservation Biology.

“These units provide one avenue to better understand the consequences from wildlife’s perspective—such as identifying refugia during smoke events—that can provide actionable insights for conservation and management.”

Wildlife studies—especially those that capture, collar and recapture animals—are resource-intensive, and many of them already track health data, like heart rate, in addition to GPS coordinates. These data combined with smoke logger data will reveal new information about wildlife welfare and activity.

The team is partnering with researchers across the western U.S. to piggyback on studies tracking cougars, deer and elk, and they stationed sensors in the habitat of the endangered Sierra Nevada fisher, a small mammal related to weasels, to better understand the air quality in their range. Those results will be published in future studies.

They encourage researchers with projects where wildlife collars are recovered to partner with them to add smoke loggers to their sensor packages. Or, for about $100 in materials per unit, researchers can assemble their own smoke loggers by downloading the free, open-source design and programming.

Deer sensors reveal highly localized air quality

Initial deployment on mule deer revealed that air quality differed by an order of magnitude—10 times either more or less—between the deer-borne sensors and the closest monitoring stations, indicating the highly localized nature of air quality and the need to monitor individual animals to understand their exposure and response.

Deer monitored in Colorado and Utah this year were not exposed to unhealthy levels of wildfire smoke, but testing showed that the sensor is sensitive enough to register minimal air pollution spikes from traffic for urban-dwelling deer.

“That was eye-opening for us and shows how variable air quality is at a microscale,” said Wittemyer, a professor in the Warner College of Natural Resources.

The U.S. Environmental Protection Agency monitors air quality in populated areas across the country through the AirNow network. The wildlife-worn sensors will fill gaps in data and deliver further health insights for people exposed to smoke too.

A low-cost design for remote monitoring

To design an affordable tool, the team repurposed a low-cost, commercially available sensor similar to the ones used by the PurpleAir monitoring network. The sensors use a laser to measure microscopic particles known as particulate matter 2.5 because they have a diameter of 2.5 micrometers or less. These particles are detrimental to cardiovascular and respiratory health.

The solar-powered smoke logger is designed to be worn on a collar by medium and large animals and must be recovered for the data to be downloaded. Transmitting data would be costly and would drain the device’s battery, limiting its lifespan, and there is no connectivity for transmission in wildlands. Instead, air quality data is recorded and stored every 30 minutes.

Planning burns to limit wildlife exposure

Ditmer said a stronger understanding of how smoke affects wildlife health will improve conservation planning and allow prescribed burns to be timed to reduce risk to wildlife.

“Prescribed fire is an important tool for managing forests in the face of increasingly severe wildfires, and understanding when and where smoke actually reaches wildlife could help managers plan burns that meet forest-management goals while reducing exposure during sensitive periods or in important habitats,” he said.

Who’s behind this story?

Sadie Harley

BSc Life Sciences & Ecology. Microbiology lab background with pharmaceutical news experience in oil, gas, and renewable industries.

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Robert Egan

Bachelor’s in mathematical biology, Master’s in creative writing. Well-traveled with unique perspectives on science and language.

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