Each day at Sacramento International Airport, a high-stakes turf war unfolds in the fields beyond the runways.
Armed with noise cannons, squawk boxes, shotguns and rifles, airport biologists patrol the grounds, shooing and often shooting avian intruders in hopes of reducing bird strikes, one of the airline industry’s oldest problems. Similar scenarios play out at airports nationally, but they are especially common in Sacramento, which sits beneath the giant bird migratory route known as the Pacific Flyway.
Bird strikes pose a potentially significant hazard for planes. A Southwest Airlines flight hit a bird eight minutes after takeoff this month and was forced to return to the airport when one engine lost power. A similar incident forced a commercial airliner to make a precautionary landing in November.
Sacramento has one of the highest bird strike rates in the country. This time of year, it’s easy to see why. The airfield is surrounded by Natomas basin farmland, much of it prime habitat for birds, including rice fields flooded in winter. Flocks of geese could be seen last week resting in the watery fields on both sides of Highway 99 just north of the airport under commercial jet flight paths.
“Thousands of them,” Glen Rickelton, a Sacramento airport manager who oversees the airport’s wildlife hazard management program, lamented last week.
The county’s decision to build the airport in Natomas wetlands in 1967 proved to be a mixed blessing. “We don’t have people living too close by,” he said, “but we end up with thousands of acres of habitat that we have to find a way to coexist with.”
Airport crews work to keep the grounds mowed and dry. But this year’s rains are starting to saturate the ground, Rickelton said. If that continues, pooling water could attract more birds.
Planes at Sacramento airport have collided with birds 113 to 200 times a year over the past decade.
Planes arriving or leaving Sacramento International have collided with birds anywhere from 113 to 200 times a year over the past decade, a Sacramento Bee review of federal data shows. The peak years in the decade were in 2009 and 2010. Strike reports have dropped off in the years since, but not by a lot. There were 134 in the most recent data year, 2014.
National experts recently reported mixed evidence that they say suggests the industry is making progress in reducing strike risks. The total number of strikes reported nationally is on the rise, but that may be due to more vigilance and reporting by airports and airlines, bird strike analysts say. More notable, they say, is that the more serious bird strikes, the ones that damage planes, have been falling since 2000.
Strikes generally pose much bigger problems for birds than to humans. In roughly 9 out of 10 strikes, there is no damage to the jet. When there is damage, it often is minor. Sacramento airport officials say they have no record of any human injury from a bird strike here.
But in rare occurrences, bird strikes have disabled planes. The Federal Aviation Administration reports 25 human deaths from bird strikes since 1990.
It is a problem we have to keep on top of.
Archie Dickey, director of the Center for Wildlife and Aviation at Embry-Riddle Aeronautical University
The problem is not new.
Orville Wright struck a bird in an Ohio field in 1905. In 1960, a flock of starlings caused a commercial jet to crash in Boston harbor, killing 62 people.
Many airports and airlines have attempted to deal with it for years, but the issue did not get much publicity among the general public until a spectacular event in 2009 prompted federal safety officials and local airports to reassess their efforts. A U.S. Airways airliner taking off from LaGuardia Airport in New York ran into a flock of geese and lost power in both engines. The pilot managed an emergency water landing, belly-flopping the jet on the Hudson River without serious injury to passengers.
That incident, referred to in the aviation industry as the Miracle on the Hudson, drove home a point. “It is a problem we have to keep on top of,” said Archie Dickey, director of the Center for Wildlife and Aviation at Embry-Riddle Aeronautical University. “The public needs to be in support of trying to reduce this.”
Cleared for landing
Since then, airports and airlines have stepped up reporting and analysis of bird strikes, beefing up bird management efforts, many by hiring biologists. Sacramento, which had a robust program before the Hudson River incident, spends $350,000 to $500,000 annually to keep birds at bay. It employs two and sometimes three biologists.
The tactics are often proactive and basic. Airport workers reduce shelter and feeding areas on airport grounds by cutting the grass, pruning trees and draining ditches. They also set traps near runways to catch small prey that might attract large birds.
Last summer, during the drought, the airport’s wildlife team sprayed insecticide around both runways to quell a grasshopper population boom that was attracting swallows and causing a spike in small bird strikes. This summer, airport officials plan to increase the spray area.
Much of the daily work, though, involves what biologists call hazing and harassing. That includes firing pyrotechnic pistols at birds, and placing booming propane cannons and squawk boxes around airport grounds. Biologists drive around in trucks honking the horn at birds. The airport has tried falconry, bird dogs and remote-controlled vehicles at times to chase birds away, but Rickelton said the effectiveness of each was limited.
When harassing methods don’t work, the fight gets deadly. Biologists shot more than 1,300 birds on airport grounds in 2013-2014, the most recent reported year. The airport is required under a federal “depredation” permit to count and report every shooting.
That tactic has drawn ire from some wildlife advocates, but airport officials say it’s needed.
1,323 Recent tally of bird kills at the airport
“If a bird is sitting on the side of the runway and that bird is just not going to leave ... we will use lethal force to preserve the safety of the operations of the airport,” Rickelton said. “That is a judgment call. It’s an option of last resort.”
Federal wildlife officials place specific limits on the number of birds of various species the airport can kill each year. In its most recent report, the airport listed 707 kills of the birds in permit-covered categories. Those included 191 cliff swallows, 138 western meadowlarks, 36 great egrets, 17 great blue herons and eight red-tailed hawks.
The airport killed another 616 birds in groups for which there are no limitations. More than 500 of them were blackbirds, the No. 1 species shot at the airport.
“It’s a function of their numbers and their persistence,” Rickelton said of blackbirds. “You have big blocks of them and they just won’t leave.” He said he had honked his horn that morning at a group of blackbirds on an airport fence, but the flock simply hopped into the air for a few seconds and then came back down.
Some Sacramento environmentalists and wildlife advocates criticized the airport’s approach, saying they wonder if it’s overkill.
“I seriously question whether what they are doing is necessary,” said Jim Pachl, a longtime bird advocate. “If you shoot a bunch of them, a bunch more are going to move in. It sounds like laziness.”
Sacramento is among many airports where shooting occurs. “It’s almost always controversial,” said Chris Oswald, vice president of safety and regulatory affairs for the Airports Council International – North America. “I’d love to say we don’t need to do that, but it is an important tool.”
In Sacramento, Rickelton said he believes his team’s multipronged approach has reduced the risk of strikes on or close to airport property. He pointed out the window of his airport office at neatly mowed fields with only a few birds in sight inside the airport fence line. But he said the airport can do little about the many bird strikes that happen after takeoffs or before landings a few miles off airport grounds.
Mike Begier, chair of the national Bird Strike Committee, a group that includes the Department of Defense, commercial airports, the aerospace industry and private sector, thinks increased awareness is having positive effects.
Begier and colleagues recently presented study results that show, in particular, a reduction in damaging strikes closer to airports, where airport hazard management teams have more control. Begier estimated the reductions have saved the industry $300 million since 2000, and possibly saved human lives.
Begier, who also is national coordinator of the airport wildlife hazard program in the U.S. Department of Agriculture, said the numbers show increased vigilance is having an effect. “Is there more work to be done? Yes,” he said. “There has to be diligence. Proactivity.”
An evolving technology, called “avian radar,” may help airports and the Federal Aviation Administration get a better real-time handle on bird movements across airfields in the coming years. It could even allow controllers to hold flights momentarily until a threat passes, said Oswald of the Airports Council International.
The problem won’t be going away, though, because birds are persistent, said Dickey of Embry-Riddle Aeronautical University. He said he once saw a hawk at Sacramento airport sitting on a noise cannon. The hawk had the cannon timed. Just before it went off, the bird flew a few feet away, then landed back on the cannon again.
“You can’t put a dome over the airport,” he said. “Birds and animals are going to move across. No way of stopping that.”
Biologists working for the Sacramento International Airport shot more than 1,300 birds in 2013-14. The list:
Great blue heron
Black-crowned night heron
*Emergency take report filed
Source: U.S. Fish and Wildlife Service