Canada geese: They’re big, loud, often ornery creatures willing to stare down an approaching car, never mind a person, rather than budge an inch.

Now imagine their mood while being restrained and flipped onto their backs so that someone can swab their bottoms.

That would describe the frenzied scene near Rockport one morning last week when dozens of Canada geese became unwilling participants in Maine’s latest campaign against avian influenza.

Corralled and then manhandled by a team of state biologists, the geese are among hundreds or perhaps thousands of migratory birds that will be tested this year as part of an early warning system for bird flu.

Biologists hope these goose roundups – as well as similar testing on Arctic terns, common eiders and black guillemots – will help them detect the deadly H5N1 bird flu virus in Maine’s population of wild birds before it leaps to the state’s sizable commercial flocks.

No birds in Maine or anywhere else in the U.S. have tested positive for the H5N1 strain, which has devastated poultry flocks in Southeast Asia and has popped up in Africa and Europe.

But federal and state agencies are ratcheting up bird flu testing of both wild and commercial flocks nationwide in anticipation of H5N1’s eventual arrival in the United States. Health officials also are bracing for the worst-case scenario of H5N1 mutating into a form transmissible from person to person.

On Friday, a crew from the Maine Department of Inland Fisheries and Wildlife and volunteers paid a visit to Tolman Pond, a small but scenic body of water off Route 90 that is the seasonal home to about 80 to 100 Canada geese.

The team of biologists and volunteers timed their visit to catch the birds while they were molting, meaning most were unable to fly and therefore easier to corral.

Canada geese were chosen because they are primarily wetland dwellers that often intermingle with species of other migrating birds, said Michael Schummer, a DIF&W biologist and game bird specialist who helped lead the roundup.

Scientists fear migrants could carry the virus to the U.S. from Europe or Africa.

“There’s a fair number of them, they are easy to catch, and they are statewide, so they are a good sentry bird,” Schummer said. “If anything is going to pick [bird flu] up, it seems likely to me and to other biologists that it would be the Canada goose.”

The roundup started on the water as boaters in two canoes and a kayak corralled the geese into one end of the pond. With help from people positioned on the shores, the boaters then attempted to herd the geese into a V-shaped pen on the shore formed by stringing nets around poles.

The first attempt fell apart when a majority of the geese darted between the boats to open water. The second try worked seamlessly, however, and the geese marched into the makeshift pen. The flightless geese then were huddled into an even smaller, gated pen to prevent their escape.

Just because Canada geese are “easy” to catch does not mean they are pleasant patients, however.

The geese squawked, squirmed, scratched and bit the crew members as they moved the birds from the pen into smaller cages. Each bird then was fitted with a leg band – if they didn’t have one already – as part of a population survey and recorded as male or female.

The trained crew employed an unusual-looking but effective technique to calm the struggling birds. While holding the goose on the ground or in their laps, the handlers would grab the goose’s head and tuck it under one of the bird’s wings.

Most birds were then calm enough to be flipped onto their backs for examination and testing. Some birds appeared to enter a trancelike state that lasted until a worker lifted the bird’s wing to re-expose the skinny, black-and-white head.

“That bird would lie there all day if we let him,” Schummer said as he gently placed a docile bundle of feathers on the ground. “It’s like putting blinders on a horse.”

With a little help from Schummer, the goose roused itself and immediately bolted for the water and the rest of its flock, by then huddled on the opposite corner of the pond.

About 40 birds were handed over to Sarah Fleming and Danielle D’Auria, two DIF&W workers who were collecting samples for bird flu testing. The pair used long swab sticks to collect fecal samples from the goose’s cloaca, the opening on the bird’s bottom that leads to the intestinal tract and reproductive organs.

The samples were placed in test tubes filled with a serum, which will be sent to a lab in Connecticut for analysis. The test results go directly to the U.S. Department of Agriculture’s Wildlife Services program.

Schummer said Maine is still developing its response plan for if and when the H5N1 virus appears in the state. In all likelihood, the federal government would take the lead at least initially to attempt to isolate and eradicate the virus.

DIF&W also plans to collect fecal samples from some game birds killed during hunting seasons.