UNIVERSITY PARK, Pa. — Chances are, the flock of geese that U.S Airways Flight 1549 flew through Jan. 15 before crash landing in the Hudson River was not composed of migrating birds, according to wildlife experts in Penn State’s College of Agricultural Sciences.
The birds that were sucked into and destroyed the Airbus A320 jet’s engines were likely resident birds that live near New York’s La Guardia airport, said Margaret Brittingham, wildlife resources professor.
“The timing of the accident suggests that those were not migrating geese,” she said.
“Geese migrate along the Atlantic Flyway between their breeding grounds in northern Canada and their wintering grounds in the southern states, but in mid-January these were probably local birds flying not far from home.”
LaGuardia is not much different than many airports around the country, points out Gary San Julian, a wildlife resources professor who specializes in wildlife-damage issues.
Philadelphia’s airport, for example, also has bird problems because it sits next to the John Heinz National Wildlife Refuge at Tinicum.
“Airports, by their very nature, attract waterfowl,” San Julian said. “They have such huge water-diversion needs that they create ponds. The airports have no choice but to get the water off runways so planes can take off and land.”
The vegetation around those airport ponds often is kept carefully trimmed, and that just exacerbates the problem, according to San Julian.
“Well-manicured, grassy areas near water are especially attractive to geese, because the birds like to be able to see areas around them to avoid predators,” he said.
Airports are working to reduce risks by using Doppler radar to track flocks of birds in conjunction with information on bird-migration patterns and where birds are likely to concentrate, said Brittingham.
“A bird-avoidance model created by the Federal Aviation Administration and the U.S. Air Force can be used to predict the probability of a bird strike and allow pilots to proactively avoid those areas,” she said.
“Obviously, nothing is going to be 100 percent effective, and we need to continue to refine this system and to get this information to pilots in real time.”
Most people think resident Canada geese are like obnoxious relatives who visit and wear out their welcome, Brittingham said. They believe migrating birds just stopped and decided to stay year-round. But that’s not the reason for large flocks of the big, noisy, black-and-white waterfowl crowding airports, golf courses, campuses and beaches around New York, Pennsylvania, Maryland and other northeastern states.
It’s a widely misunderstood phenomenon, she explains. The resident geese problem is actually an unexpected result of intentional attempts to help geese when populations were low.
“First of all, you have to understand that there are a number of different races of Canada geese,” she said.
“They are similar to subspecies, but not as distinct. However, there are slight differences in their behavior.”
By the early 1900s, migratory Canada geese populations that breed in the Hudson Bay region of Canada and winter in the Chesapeake Bay area were in sharp decline due to over-hunting. Those birds flew over Pennsylvania, providing biannual enjoyment for birdwatchers and hunters. Beginning in the 1930s, according to Brittingham, state and federal wildlife agencies throughout the Northern Flyway stocked geese captured in other places to establish breeding populations and restore recreational opportunities.
In Pennsylvania, for example, a race called giant Canadas was released. Those birds came from Minnesota and Wisconsin. The giant Canadas are larger than the Atlantic migrant geese — averaging 12 pounds compared to 8.8 pounds for migrants — and never migrated much from their homes in the Midwest.
“So of course they never migrated in Pennsylvania either,” said Brittingham.
“At the time they were released here, the giant Canadas were rather rare, but they aren’t now.”
When the U.S. Fish and Wildlife Service adopted a regulation that outlawed the use of live decoys for goose hunting, according to San Julian, a number of sportsmen’s clubs liberated large flocks of geese. These birds, probably migratory geese and their offspring trapped locally years before, had lost their instinct to migrate. They had adapted to living year around in Pennsylvania and Maryland.
For a few years the birds were trapped and transferred from problem areas to other counties in Pennsylvania and to other states.
“Other states no longer want them,” said San Julian.
“And we just spread the problem around the state. Today we have geese nesting in every county in the state.”
The management of resident geese is extremely complicated, Brittingham points out. Populations of migrating Canada geese are decreasing because of poor reproduction on their arctic breeding grounds and competition there from vast numbers of snow geese. Hunting of migratory Canada geese is being curtailed.
“It’s a dilemma for managers,” she said.
“They must decrease the hunting pressure on migratory geese and increase it on resident geese. But that can be a problem in urban areas because it upsets the animal-rights folks and the people who like to feed the birds. Managers must time hunting seasons so that migrating birds have headed south and only resident birds are available.”
Resident geese have become a major hunting resource, said San Julian. He says more than 70,000 non-migrating birds are taken by hunters annually in Pennsylvania. The U.S. Fish and Wildlife Service has permitted states such as Pennsylvania to lengthen resident goose-hunting seasons, lengthen legal shooting hours and liberalize bag limits.
Surprisingly, according to Brittingham, it appears that there has been little interbreeding between resident geese and migrating geese even though they may be wintering in the same areas.
The Pennsylvania Game Commission estimates that there are 250,000 resident geese in Pennsylvania. They have become a major nuisance, causing pollution on state park beaches and significant amounts of crop damage. Brittingham notes it has been difficult to control their numbers solely by hunting. Other population-control measures are being considered.
“Managers are looking at euthanizing birds and destroying nests and eggs,” she said. “It’s getting to the point they have to do something.”