That honking you hear? It's probably a Canada goose

There's an awful lot of honking during the evening rush hour.

These aren't commuters with uncontrollable road rage, they're Canada geese keeping track of each other as they commute to and from roosting areas on open water. They are a noisy bunch, and there are lots and lots of them.

The ubiquitous Canada goose is the one of the most recognizable birds in our area, both audibly and visually. It's also one of our more challenging wildlife neighbors that elicits a mixture of fondness and ire among suburbanites.

As a species, the Canada goose is made up of at least 11 subspecies, or races. (Note that there is no such species as Canadian Goose; we're talking Canada goose here.)

All the subspecies share that Canada goose gestalt: long black neck on a brownish body, white cheek patch topped by a black head. To differentiate the subspecies, size is the usual guide. Some of the small races average six pounds and have four foot wingspans while large races may weigh as much as 20 pounds and have wingspans of at least five-and-a-half feet. The smaller races hail from the northern parts of Canada; the larger ones are found farther south. Darker forms live in the west. Lighter subspecies are easterners.

Canada Geese hang out in mixed crowds at different times of year. A variety of subspecies may congregate in the same area, especially during migration. If you scan a pond crowded with geese, you may spot big ganders mingling with decidedly smaller ones. Some subspecies in these mixed flocks may be moving on, others may be staying for the winter, some may be yearlong residents.

The composition of flocks has changed over the years as migration, wintering and breeding patterns have changed. Populations of geese that used to migrate farther south are now shortening their trip for the winter and settling in here. These mix with the subspecies for whom this is "south" and with some who migrate very short distances. Some just stay put all year long. Thus, looking out at a pond packed with geese, you may not know who's who - or where they came from.

What accounts for the shift in migration destinations? According to the Cornell Laboratory of Ornithology, changing agricultural practices have played a role. Corn and other waste grains are available in many fields throughout winter, providing a reliable winter food source. In addition to agricultural fields, the urban landscape has been welcoming to geese. Vast expanses of mowed turf grass provide a reliable food source and a clear view of potential predators. Thirdly, the proliferation of detention ponds has insured open water for geese and other waterfowl in winter.

If it seems like there are a lot more geese than there used to be, there are - relatively speaking. It's important to look at the big picture, though, when considering populations. Historically, the Canada goose population plummeted in the early 20th century. Waterfowl, shorebirds, songbirds and game birds all took a big hit from over-hunting, the millinery industry, and devastating habitat loss. The sight and sound of Canada Geese flying in V-formation in the sky became a rarity for most of the century. The sight of a gaggle of geese was a cause for celebration.

The subspecies known as the Giant Canada goose was thought to be extinct until 1962, when Dr. Harold Hanson of the Illinois Natural History Survey discovered remnant populations in upstate New York and Minnesota. Subsequent legislation and habitat restoration revived the numbers of the Giant Canada goose, and its recovery has been a huge success story in wildlife management. Not only did Giant Canada goose populations recover, they skyrocketed.

There are indeed huge numbers of several subspecies of Canada Geese in northern Illinois. The Canada goose dominated last month's annual winter bird count in Kane and DuPage counties. Close to 8,000 geese were tallied in December 2009, up from 2,000 the year before. Compare these numbers to those of winter bird counts in the 1970s when the average number of Canada Geese was about 300, and you'll see the success of species management and habitat restoration.

But too much of a good thing is, well, too much. In many parts of its expansive range, the Canada goose has become a pest. Golf courses, parks, school playgrounds, cemeteries and parking lots are sullied by the droppings of grass-eating geese. Known in the vernacular as "goose poop," this yucky stuff can ruin a picnic or a game of Frisbee. Goose poop is no small problem, either. According to National Geographic, "just 50 geese can produce two and a half tons of excrement in a year." On beaches, the accumulation of goose droppings brings the risk of fecal coli form bacteria.

Canada Geese have posed significant safety hazards on runways at airports. It was one year ago this month that US Airways Flight 1549 was brought down by an encounter with an airborne geese, resulting in the famous "splash-landing" in the Hudson River. The geese did not live to tell the tale, but 155 human passengers did.

As with most animals that reach the notoriety of nuisance status, the Canada goose has become problematic due to our own actions. We have created conditions favorable to geese in migration, in wintering, and in breeding seasons. Urban sprawl continues apace, creating even more acres of closely-cropped lawns, detention ponds and open water. Airports with acres of grass-covered land accommodating runways are not the geese's fault, per se. The habitat is there, the geese take advantage of it, and large metal birds with wheels happen to get in their way.

The Canada goose has become a species to reckon with. Protective legislation and habitat restoration brought these birds from the tough times of severe population loss to the boom times they enjoy today. Now wildlife management must shift its goals to manage the prolific populations of geese.

"Habitat modification is the most successful approach to dealing with goose problems," according to Amanda D. Rodewald, Assistant Professor of Wildlife Ecology and Extension Wildlife Specialist at the Ohio State University. "Allowing tall, thick vegetation to grow around ponds or in open areas will deter geese from using an area." Scare tactics may also be used, such as loud noises, scarecrows and herding dogs. To be effective, these measures must be taken as soon as geese arrive in an area and must be used repeatedly. Licensed wildlife control operators are often employed to addle eggs and utilize other methods of population control. And of course, hunting in the fall/winter hunting season helps keep some population counts down. Hunting also provides food for the hungry in many areas where hunters donate goose meat to local food banks.

There are groups of citizens who oppose the killing of any geese, and there are people who would like to wring the neck of every goose they see. Canada Geese are protected by Federal and State laws, prohibiting the general public from killing geese without a permit or harming eggs from nests. The Canada goose problem, however, is largely man-made and an argument can be made for our responsibility to fix the mess that we have created. Wildlife control operators and land managers can and do take measures to prevent overpopulation of geese. The goal of wildlife management, however, has never been to eliminate populations. Rather, the goal is to bring them to healthy levels for the ecosystem and for humans as well.

When you see that chevron in the sky as a gaggle of Canadas comes in for a landing, remember that this was once a rare sight. Consider the cacophony of honking as heralding in the New Year for wildlife and humans alike.

• Valerie Blaine is the nature programs manager for the Forest Preserve District of Kane County. You may reach her at blainevalerie@kaneforest.com.

<p class="factboxheadblack">Why do geese fly in a V formation?</p>

<p class="News">There's an old joke that still makes the rounds in cyberspace: "Do you know why the V formation of a flock of geese is sometimes longer on one side than the other?" Answer: "Because there are more geese on that side."</p>

<p class="News">Whether you laugh or groan at this oft-repeated joke, you may wonder, "What's the real reason that Canada Geese and other birds fly in V formations, symmetrical or not?" Modern analysis of flight has shed light on this question. Aerospace engineer Jeff Scott explains on the Web site <a href="http://www.aerospaceweb.org" target="new">www.aerospaceweb.org</a>, "Birds fly in this way for two reasons. The first reason is that the shape of the formation reduces the drag force that each bird experiences compared to if it were flying alone. This decrease in drag occurs thanks to the formation of wingtip vortices. These vortices are generally undesirable because they create a downwash that increases the induced drag on a wing in flight. </p>

<p class="News">"However, this downwash is also accompanied by an upwash that can be beneficial to a second wing flying behind and slightly above the first. A bird flying in one of these upwash regions essentially gains free lift ..."</p>

<p class="News">You may or may not follow all the physics, so suffice it to say that the guy in the lead position has the toughest job. The two birds on the ends of the V are also working extra hard. The ones in the middle cruise with ease. When the lead and two aft pilots get tired, the squadron shifts positions. Thus everyone gets a break at some point during the journey.</p>

<p class="News">The second reason for V-formation flight is the increased ability to see and communicate with other birds in the flock. This is especially important on long migration routes. </p>

<p class="News">Occasionally I spot a lone goose honking forlornly in the sky. Knowing how tough a solo flight is, I can't help but hope it will rejoin a flock, falling into position on to that shorter side of the V to even things out - and put the cyber joke to rest at last.</p>