Resident geese have long been a problem in Santa Clara County and across the country, leaving their droppings on paths, chewing grass down to its roots and aggressively defending their nests.
The flocks were originally migratory, and some still fly to Canada every spring. However, many of the birds have discovered that the Bay Area's temperate climate, lush parks and lack of natural predators make an ideal habitat, according to Melanie Weaver, California Department of Fish and Game associate biologist.
As a result, many Canada geese have never left. At least 300 of the creatures reside in Palo Alto's Baylands Nature Preserve alone, with more living throughout the county, Baylands Park Ranger Daren Anderson said.
The geese, most commonly found in parks and golf courses, are becoming a problem at the Palo Alto Airport, which is adjacent to the Baylands, according to Director of Santa Clara County Airports Carl Honaker. The fowl find the airport's undisturbed greenery a wonderful nesting and feeding place.
"The airplanes can hit the geese in flight. They're big birds ... and if you're hitting at 120 miles per hour, the best case is that there's the least impact and some damage happens," he said, referring to the fact that geese can weigh up to 14 pounds. "Worst case is the plane can't fly anymore and it crashes."
While there have been no major dangers posed by local geese so far, pilots have been told by Palo Alto traffic controllers to reroute their flight paths in the immediate airport vicinity in order to avoid hitting the fowl.
Birds as aviation hazards are a problem from Palo Alto Airport to the John F. Kennedy and LaGuardia airports in New York City. In early 2009, birds flew into the engines of an airplane departing from New York, forcing pilot Chesley Sullenberger to make an emergency landing on the Hudson River. The geese pose such a danger that, annually, wildlife biologists round them up in New York City's Prospect Park and gas them.
Euthanizing geese is not a population-control tactic used in the Bay Area. Instead, for the past 10 years, Palo Alto Airport officials said they have used noisemakers to scare geese away from the runways and nearby areas. But lately, the geese have caught on.
"The previous methods don't work anymore," Honaker said. "Nowadays, you use a noisemaker, they just move a couple feet over because they know you're not going to hurt them. We have five or six generations of geese who don't know how to migrate. They've lost that natural need."
Anderson is helping officials to develop new methods of controlling the geese. They've tried placing images of goose predators, such as coyotes, in the areas where the geese are commonly found. They're experimenting with different noisemakers. However, the population has not significantly decreased.
Honaker and Anderson are in good company when trying to tackle the goose dilemma. They're part of a larger group of parks and recreation officials, spearheaded by the Mountain View Parks and Recreation Department.
"We realized that in order to control the Canada geese population it couldn't be just one part of this area that's doing it," Anderson said. "So an entire group of cities in this area is partnering together."
The federal Department of Fish and Wildlife transferred jurisdiction over controlling nuisance geese to states in 2006, according to Weaver. However, at that time, no state laws existed detailing how such a problem should be handled.
As a result, the California Fish and Game Department passed new guidelines in 2008, which allows the state to issue geese-control permits to cities, although the permits are not necessary for largely urban areas such as San Francisco and Palo Alto. These cities merely have to monitor the goose population and report back every couple of months.
The goose-control permit mainly allows officials to oil eggs, which cuts off the oxygen flow and prevents them from hatching. This keeps the population of resident geese in check, although it doesn't affect the population of migratory geese.
According to Mountain View Park Manager Jack Smith, oiling is a common, though time-consuming, process that takes place in the spring. When the geese start nesting, parks and recreation employees from Palo Alto, Mountain View and other neighboring cities search goose habitats three times a week for two months to oil the bird eggs.
Another goose-control method used by cities is provided by Lucy's Gooses, a company that takes border collies to parks and golf courses to chase the geese away, Smith said.
Mountain View also hired an environmental consulting firm, which determined that freshwater ponds in golf courses are partly to blame for the large population of birds.
"We're doing a pilot project in which we've emptied two ponds on courts and have seen (the) number of birds reduced," Smith said. "We're trying to apply that to other places and permanently fill in more ponds."
So far, two ponds on the back nine holes in the Shoreline Golf Course have been filled in.
Smith said that these efforts have been helping to contain the number of geese. In the past, the population was rising by 200 to 300 geese a year, but in 2009 the number declined by 300. This year, it has remained the same.
"We're just trying to do as much as we can," Smith said. "Our target number for resident geese is zero."