The Leading Cause of Wildlife Biologist Deaths

Air crashes, in fact, accounted for 66% of the 122 job-related deaths of wildlife biologists documented by D. Blake Sasse, a biologist with the Arkansas Game and Fish Commission. Sasse reported his initial findings of 91 fatalities in a 2001 study and updated his research with 31 more deaths over the past 20 years. He also maintains a memorial website listing all those biologists.

Even though job-related deaths of wildlife biologists declined over the past two decades from a record 29 during the 1990s to 14 fatalities from 2000 to 2010 and 17 from 2011 to 2020, airplane and helicopter crashes still accounted for 66% of those deaths, Sasse said.

Last year was especially deadly for the profession, Sasse reported, with air crashes claiming six of the seven (86%) job-related deaths in 2020. That annual toll is the same as those in 1974 and 2010, both highs.

Three of those aircraft fatalities occurred Aug. 8, 2020, at the Black Gap Wildlife Management Area in Texas near the U.S.-Mexico border in Brewster County, 300 miles southeast of El Paso. The men, all Texas Parks and Wildlife employees, died in a helicopter crash while surveying desert bighorn sheep. Those killed were Dewey Stockbridge, the project’s lead wildlife biologist; Brandon White, a department technician; and Bob Dittmar, a wildlife veterinarian. The helicopter’s pilot survived.

Dittmar, White, and Stockbridge were well known and highly regarded by their peers nationwide. Their deaths shocked all who knew them. “That one hit close to home,” said a U.S. Fish and Wildlife biologist whose spouse often flew similar surveys with the same pilot and same helicopter.

The deadly crash also made the couple consider the risks of aerial surveys, which routinely require low-level, low-speed flying.

“It caused a real tense period in our marriage,” the biologist said. “We’re now parents and our risk tolerance is lower. When you’re single or don’t have kids, it’s easier to think, ‘aerial surveys are what I do.’ It’s your identity. You think it’s God’s work. But the only ones who maintain that attitude are ‘Norwegian bachelor’ biologists. They never married and they don’t have kids. Most married parents grow hesitant about flying for science. They fly because it’s their job, but they don’t want to die for a deer.”

Biologists conduct aerial reconnaissance for everything from bats to bears. Sasse said he couldn’t always identify which animal species biologists were studying when they died. For those he could pinpoint, however, 17 of the 122 deaths involved studies on elk, mule deer, or whitetails; and six involved moose. In other words, ungulates accounted for at least 23 (19%) of the 122 aircraft-related deaths.

Routine Risks? Despite such tragedies, most wildlife biologists don’t consider their profession hazardous or deadly. After all, many of them seldom or never climb into aircraft to track wildlife with radio-telemetry equipment; or to survey wildlife and their habitats with cameras, binoculars, and handheld clickers. Those two tasks account for 76% of the air fatalities Sasse documented.

Biologists who keep their boots on the ground more often watch for venomous snakes, Lyme-carrying ticks, and more routine health-related risks. Like most Americans, they’re probably more likely to die of natural causes or heart attacks on the job, which combined for 82 (31%) of the 266 on-the-job fatalities of National Park Service personnel since 1908. In comparison, 22 NPS personnel have died in air crashes, or 8% of the fatalities.

Less common hazards that killed wildlife biologists in Sasse’s analysis were drownings, car/truck accidents, murders, exposure, snakebite, lightning, avalanche, wildlife disease, prescribed fires, off-road vehicles, and tractor roll-overs. He includes pilots in those deaths if they were also biologists or alone in the aircraft while conducting wildlife-related work.

He also includes law-enforcement officers if they died while involved in wildlife research, habitat improvement, or wildlife feeding projects.

“The most surprising thing in those other causes was how few wildlife biologists have died in car or truck crashes, given how long we’ve had motor-vehicles and how much our work requires them,” Sasse said. “We had five driving fatalities through 2000 and only two since. We also had our first ATV fatality pop up within the past 10 years. On the other hand, we haven’t had a biologist drown since the 1990s.”

What Causes Air Crashes? Jobs that require frequent flying in helicopters and small airplanes are inherently riskier for biologists and others. Aircraft pilots and flight engineers, for example, ranked second in a 2018 analysis of the United States’ most dangerous jobs. The AdvisorSmith report showed pilots and flight engineers suffered 70 deaths in 2018, a rate of 53 fatalities per 100,000 workers. That trailed only logging workers with 56 deaths and 111 fatalities per 100,000 workers.

Of the 31 airplane and seven helicopter crashes that killed biologists in Sasse’s 2001 analysis, investigators determined the cause of all seven helicopter crashes but only 11 of the airplane crashes. Of the identified airplane causes, six were aerodynamic stalls, three were impacts with powerlines, and two were downdrafts. Of the seven fatal helicopter crashes, two were caused by mechanical failures, two by impacts with powerlines, and one each by downdrafts, bad weather, or impact with a tree.

Sasse said aerial tracking and survey work differs from most types of flying. “It requires flying at low altitudes like 150 to 200 feet while going as slow as possible to see things better,” he said. “Things can go wrong quickly when you’re going slow and have little time and altitude to react and recover.”

Cyril Griesbach flew small airplanes 18 years for the Wisconsin Department of Natural Resources after flying seven years for a freight-hauling flight service. His agency work varied from flying 150 feet above rivers to track lake sturgeon to flying 7,000 feet high at night to watch for poachers’ spotlights. He regularly flew 200 feet above creeks, woods and marshes with biologists to monitor goose migrations, beaver colonies, and deer distribution.

“Pilots have a saying: The three most worthless things in flying are fuel in the truck, a runway behind you, and altitude above you,” Griesbach said. “The closer you are to the ground, the smaller your room for error. Aerodynamic stalls aren’t about the engine stalling. Pilots get into trouble on aerial surveys when they’re twisting along over rivers, and think they missed something. They make a quick turn for a second look, and their wings lose lift because they’re going too slow.

“You can’t let your ego control your reaction,” Griesbach continued. “Your job is to apply your aircraft to the task at hand. The prudent, sensible thing to do is just go around, make a sensible turn, and come back. Flying for resource management is never routine. You’re not just hauling people or freight to from one point to another in a straight line at a fixed altitude.”

The Thrill of Flying Bob Zaiglin of Uvalde, Texas, owns and operates Zaiglin’s Wildlife Resources Management Consulting Service, and is the wildlife-management coordinator at Southwest Texas Junior College. Since 1976 Zaiglin has regularly ridden helicopters to within net-gunning range of whitetails and tickling reach of mesquite trees. He’s also flown within pitching distance of the canyon walls and mountainsides where White, Dittmar, and Stockbridge died in August 2020.

“Flying wildlife surveys is damn-near a sexual experience,” Zaiglin said. “Everyone is excited. It’s high-profile stuff. I’ve never crashed because I got lucky when I was young. After getting some experience, I’ve only flown with damned good pilots with damned good equipment. But no matter who’s the pilot, I pay attention. All pilots think they’re the greatest, and everything is great when things are going smoothly. But you can’t know if pilots are good until you’re in a dangerous, life-threatening situation.”

Zaiglin said he’s fortunate to fly most surveys over flat “user-friendly” terrain. Even so, to get deer up and moving for censusing and sex-ratio identification, Zaiglin’s pilot must keep their helicopter low. They’re often 50 feet or below because deer learn to hunker from helicopters, especially if they’ve been gun-netted before. Zaiglin also works often near the Texas-Mexico border, where deer grow accustomed to U.S. Border Patrol helicopters.

Zaiglin’s worst scare in recent years was hearing a loud “Pop!” behind him and his pilot, Dusty Holt. “We were about 30 feet above the ground, going 35 to 40 miles an hour,” Zaiglin said. “Dusty shut things right down. Seconds later we were on the ground 50 to 75 yards away. Dusty got out and found the tail rotor had blown a ball bearing. It was still turning, but if we had kept flying or if we had been over steep terrain and couldn’t instantly land, things could have gone bad.”

Zaiglin wasn’t surprised that 29% of helicopter crashes and 27% of airplane crashes that kill biologists involve impacts with powerlines. “You have to know the location and heights of every powerline and wind turbine where you fly,” he said. “Some ranches down here still have copper-coated powerlines. They’re invisible. You have milliseconds to spot them. You have to watch for hazards while also watching for deer, which is why we’re up there in the first place. I’m pretty good at spotting deer, and I see maybe 60 to 70% of them, but my main job up there is staying alive.”

Hazardous Alaska Roughly 4,000 miles northwest of Zaiglin’s “user-friendly” terrain is Anchorage, Alaska, home to many state and federal fish and wildlife biologists. When it comes to dying while flying for science, no place rivals Alaska and its rugged landscapes and harsh, unpredictable weather.

Even though Alaska didn’t become a state until 1959, it ranked first for killing wildlife biologists in aircraft crashes when Sasse published his 2000 research. Sasse’s study then showed Alaska with 22 deaths, beginning with Doyle E. Cisney in October 1961. Washington was next with eight, followed by Utah and Florida with six. Arizona, Wyoming, and Minnesota had five each. Alaska holds the same sad distinction for the National Park Service, which has lost 18 employees there since the first died in 1964, including 13 in air crashes.

Sasse said Alaska’s safety record has greatly improved in recent years, but still holds the top spot for aircraft-related biologist deaths with 23. Alaska is followed by Washington with 10, Arizona and Florida with nine, and Utah and California with six.

Dan Rinella, a fisheries biologist with the USFWS in Anchorage since 2016, worked the previous 16 years for the University of Alaska. He said agency and university rules and guidelines for operating research boats and aircraft have tightened considerably since his arrival in 2000. For instance, every flight stays in radio contact with dispatchers at every point in their journey.

“Alaska was a completely different experience just 20 years ago,” Rinella said. “I haven’t flown the past five years in my current job, but I never viewed my work as dangerous. I’ve probably taken far more risks at our family’s cabin (on the coastline of southeast Alaska’s Prince of Wales Island). The biggest danger you’ll always face in Alaska is its remoteness. We go through a lot of training, we always have satellite communication, and we’re always prepared to spend a night or more stuck somewhere we didn’t expect.”

Nathan Olson, a pilot-biologist and regional aviation manager for the USFWS in Anchorage, is responsible for 25 pilots and 35 planes. Olson said pilots must learn unique flying skills to survive in Alaska, and the agency is deadly serious about training them for the tasks.

“For most pilots outside of Alaska, 90% of their flying is airport to airport, so we can’t just hand the keys to a new pilot when they arrive,” Olson said. “New pilots can’t know what’s expected up here. It can take three to five years of training before they’re qualified to fly through canyons and conduct mountain surveys. We have standards and evaluations for low-level survey work, off-airport landing, float operations, and glacial operations.

“The Federal Aviation Administration has no rating system for big-tire or ski landings on ridgelines and gravel bars where no one has landed before,” Olson continued. “We have to pick up the slack on those skills. New pilots might think we’re going overboard on training, but we’re doing what needs to be done. We train the hotdog out of them. What people see on TV shows about flying in Alaska isn’t reality. All that cowboy-aviator stuff is just drama and TV production.”

Olson said good training helps ensure pilots suffer mostly bruised egos and bent airplanes when things go awry. Its requirements seem to be working. The USFWS hasn’t had an aircraft accident in Alaska in five years, and it hasn’t had an aircraft fatality since 2010 in Oregon.

Safer Skies Ahead? Olson, Sasse and Zaiglin continue to see a need for low-level aerial survey work, despite its inherent risks, and don’t yet see the work being relegated to unmanned drones.

“We have a drone program and maybe they’ll eventually prove effective, but the drones we can afford are only effective for small-scale mapping projects,” Olson said. “Most drones can’t conduct waterfowl or wildlife surveys over 12,000 square miles. You need fixed-wing aircraft for that. We’re getting further along with bigger cameras for fixed-wing aircraft, and we’re testing them in Alaska and the Lower 48 on migratory birds. We’re hoping those cameras can do surveys at higher altitudes, where banking and higher-risk maneuvers aren’t so dangerous.”

Zaiglin said he and his students have used drones to study prescribed burns and fire behavior, but they’ve yet to prove effective for deer surveys.

“They’re not seeing the deer they hoped to see,” Zaiglin said. “Drones are limited by their battery power, they need to stay fairly near the operator, and they don't generate enough noise to get deer up and moving so we can see them and identify their sex. I don’t rule drones out down the road, but so far I don’t see them replacing helicopters or airplanes.”