line line

FLY AWAY HOME: URGING GEESE TO GO

PHILIP C. WHITFORD, Biology Department, Capital University, 2199 E. Main Street, Columbus, OH 43209, USA

Expanding resident urban Canada goose populations have led to concomitant increases in human/goose conflicts in business parks, municipal parks, golf courses, and airfields. They foul the water of ponds and lakes and make a mess of lawns and golf greens with their abundant droppings, making parks and corporate properties unsightly and unsuitable for recreation and relaxation. Geese in all such locations have proven difficult to displace and keep away.  Their preference for short, highly fertilized grass, golf courses, ponds and parks, and protection from hunting found in urban settings, are all factors that attract geese to these environs (Smith et al. 1999). Still the questions remain; how did we get to this point; and, what can we do to reduce problems caused by large aggregations of geese making regular use of specific properties?

Where did the geese come from? “I don’t remember Canada geese in the cities when I was growing up,” you might say. And, you would be correct. Geese were rare in North American cities in the 1960’s and early 70’s.  In fact, the Giant Canada goose (Branta canadensis maxima), the subspecies of Canada geese most common in urban areas today, was considered to be extinct by many scientists in the 1950’s.  They were known only from records of very large geese shot in the Dakotas in the 1880’s, the last remnants of the native geese that had lived in the tall grass prairie regions of the US and Canada before Europeans arrived. Several remnant populations of these geese were rediscovered in the 1960s and major efforts were made to return them to their native areas across the upper midwest. Geese and goslings were actively rounded up in Minnesota and Michigan and translocated by State Game Departments; first to states they had been native too, and then on to any other state or province that wished them. By 1996, no state was willing to accept translocated geese from other states as problems of increasing urban goose numbers became obvious.

Why were they so actively transplanted? Perhaps it was the mystique of the birds, the illusion of wild places they brought with them. What could be more idyllic than the serene appearance of several geese gliding over the quiet misty morning surface of a park lagoon, a small flight of geese etched against the backdrop of a sunset sky? They brought a bit of the majestic sense of wilderness to the city.  In truth, they weren’t introduced into the cities. They were moved by State Game agencies hoping to provide a new resident hunting resource to many states. But, the transported geese didn’t stay in the rural refuge sites. They moved to the cities where predators were few, and food abundant. Their numbers grew rapidly.  By 2002 the giant Canada goose population had grown from several thousand birds in the 1960s to current estimates that vary from 2 million (Alge 2000) to as many as 5.5 million birds in North America, depending on whose data estimates you wish to accept. They tend to parallel the nearly exponential increases reported for goose populations in Ohio, see graph (Dolbeer 2003, personal communication based on USDA data). Yet, the increase in problems caused by resident geese is actually worse than those numbers would appear, for the problems are not in proportion to their continental population. Giant Canada geese tend to be concentrated in relatively small areas of North America – the major urban centers of the Midwest and upper East Coast regions.

What is the attraction of the urban areas for these geese?  Well, to begin with, Canada geese are primarily grazing animals. They consume great quantities of grass and prefer it to be within easy reach of the ponds or lakes that provide safety from dogs, people and other possible predators. Geese can be considered connoisseurs in gastronomic matters of grasses. They prefer the easily digestible, short, tender, high protein, grasses found in areas that are frequently mowed, and heavily fertilized; grasses typical of well manicured lawns of business parks and golf courses. In addition, they are safe from hunting in most cities. As they said in the Kevin Costner film, Field of Dreams, “If you build it, they will come.” So it is with the geese and corporate parks or golf courses with pampered lawns and picturesque water holes. They will come. And, when they do, their numbers will quickly swell to problem causing proportions. A small resident flock will attract other geese to join it, eventually decimating lawns, fouling the waters and covering the sidewalks with droppings. It is at this point the geese become the enemy, creatures scorned and despised for the damage done and the problems and costs they create for building and grounds managers. The question then becomes one of, “How do we get rid of the geese?”

Until very recently, all Canada geese were protected by international treaties covering migratory bird species. They could be killed only during specified hunting seasons and with strict restrictions on number killed and manner of harvesting them. These laws prevented people from killing geese, disturbing nests or eggs to reduce goose numbers on a property. As urban goose populations and problems rose in the 1980s, those rules were changed to permit egg and nest destruction to slow their population growth. The next change made was that resident geese were excluded from treaty protections during nesting season and when and where considered a nuisance, and thus could be killed without regard to hunting seasons if proper permits were obtained. This opened the door for lethal removal of problem geese from urban areas.

Live trapping coupled with relocation of goslings and euthanasia of adult geese captured became the standard in Minnesota in the late 1990s after treaty interpretation changes made that an option. These programs have provided some respite or reduction in problems since that time (Cooper and Keefe 1997).  But, to gain permission for lethal removal of geese, cities, golf courses, cemeteries and corporate parks must demonstrate that they have made serious efforts to try to scare geese away using at least two different non-lethal techniques and/or efforts to modify the property to make it less attractive for geese. What are non-lethal control options and how successful are they in urban settings? Many of these are discussed in  “Managing Canada Geese in Urban Environments” Smith, et al. (1999), Cornell University Press.  Those and other options shall be discussed individually in a moment. First, I feel it is essential to provide some necessary information about the habits, annual patterns of behavior, intelligence and learning ability, and the manner of learning of Canada geese. Once those things have been discussed, we can delve into the relative merits of the various goose dispersal techniques and how, when, and where they are best applied. For brevity’s sake, only references to techniques/papers not cited in Smith et al, (1999) will be included in the following sections, for the “lit cited” section would be many pages in length if I were to repeat all relevant citations in this paper.

Goose Behavior 101

First and foremost, one needs to understand that Canada geese are creatures whose lives are dominated by learned traditions and instinctive annual patterns of behavior. In migratory subspecies and populations, goslings learn their migration by flying the route with their parents. In following years they return along the same pathway and make stops at most of the same sites along the way. Why should this concern you if you are dealing with non-migratory resident geese? Well, for one thing, goslings of resident Canada geese learn where to be at each season of the year from their parents, just as their migrating cousins do. Secondly, resident geese attract migrants in spring and fall, birds that may join them for a day or the entire winter and add to your problems. Once they have stopped long term, the odds are strong these same geese will return year after year to spend their “winter vacation” on your property.

Tradition also plays a strong part in the lives of geese at the levels of where they nest and establish territories, where they take the young goslings to rear them after they hatch, and where individual geese go each summer to molt – to lose their flight feathers and grow a new set. In the instinctive changes in seasonal behavior listed above, geese have a strong tendency to go back to where they hatched; nested; brooded young, or were brooded themselves; or where they successfully molted their feathers in past years. What this means to a property owner is that, once geese have established a tradition of use of the property for any of these activities, they will predictably attempt to return again the following years at the proper seasons. This is especially true of establishment of nest sites and territories. Female geese almost always return to within a few hundred meters of where they successfully hatched a nest the prior year. They may even use the same nest site and territory year after year.  Such geese become much more difficult to remove and keep away because you have to break them of old traditions and help them establish new ones. From the goose management standpoint this means that about the time you think you’ve gotten rid of the geese for good, seasons change, new urges strike the geese, tradition takes over, and they reappear to mock you with a goose’s honking equivalent to Jack Nicholson’s “Honey, I’m  Baaaack.”

So, what is the lesson to carry away from this discourse? Zero tolerance is the only option for long-term success! Prevent geese from starting to use your property if they are not doing so at present. This isn’t always easy to make yourself do. One or two geese are charming and seductively pretty floating on your pond in front of corporate headquarters. One is tempted to let them stay. What harm can they do? Consider yourself warned. It is the beginning of major problems if you do. Geese comfortable and at ease on a site with ample food attract more geese.  They begin creating traditions of use. Soon, multiple generations of birds are fighting over territories, nesting in your flower beds, raising 4-6 goslings per pair, and leaving 1.5 pounds of droppings per day per goose across your sidewalks and lawns.

Your only option for success is not to let geese stay on your property for any length of time. Make them know they are unwelcome as quickly as you can. Within only a few hours on attractive sites they will come to feel at ease; become more reluctant to leave- and more likely to return if chased away. Soon, this is “home” for them, and they become nearly impossible to remove. On the good side of this equation is the fact that geese when they first arrive on unfamiliar grounds are edgy and easily spooked into leaving. When chased off early after arrival they seldom return. In my years working with geese I have come to the opinion that they have long memories that apply to specific places and experiences. As such, they tend to avoid returning to places where the have had bad experiences for years afterwards.

Anyone working in the realm of wildlife damage control is certainly aware that animals are driven by internal clocks that determine when daily and seasonal behaviors will shift from one pattern of action to another. Seasonal changes are most apparent in migratory species, those that are here and then gone, and only cause problems during predictable periods of the year when numbers are highest. But, even non-migratory creatures show distinct and predictable behavioral shifts as the calendar cycles from autumn to winter, spring and summer. Canada geese, whether in resident or migrant populations, demonstrate annual cycles of behavioral change. And, if you want to effectively disperse geese from urban or suburban settings, it is imperative that you understand and anticipate these seasonal behavior changes. Doing so will help you to minimize effort and gain the maximum benefit per man-hour of dispersal effort time.

What is the annual cycle of behavior for resident Canada geese?  When should you expect them to evidence their various behaviors and how do these changes affect your ability to move the geese away from your property? Perhaps the best way to approach this topic is as a simple “Calendar of the Canada Goose.” A brief annotated example follows. Descriptions of the dispersal techniques and their relative merits follows the behavioral calendar.

Seasons of the Goose: a brief perspective into the life of Canada geese

Fall behavior     September – November

Autumn/early winter is a good point to begin discourse on annual cycles of goose behavior. In September the first arctic nesting geese come riding the winds south to swell the ranks of the resident goose populations. Peak migrant numbers in northern states generally occur in early November and decrease as birds move farther south to winter the coldest months. The secret to moving migrants is to catch them when they first arrive. Each hour they spend at a given corporate park or golf course makes them less likely to leave, especially if resident geese are already there and appear at ease. Strike fast and early to get migrants to go someplace else. Once migrants join established resident flocks, they are likely take their behavioral cues from the local birds and quickly appear to loose their fear of humans and strange places. If that happens, the only road to success is via efforts to move both sets of geese via constant harassment, alarm calls, dogs, and whatever other means are legal and available to you. If the birds night roost on a pond or small lake, use boats, lights and firecrackers or alarm calls at sunset and/or after dark to cause the birds to find another sleeping location. They will move, because geese like a quiet night’s rest as much as we do. But be prepared to keep up the effort 2-3 times per night for 2-3 weeks to get them to permanently change night roosts.

Giant Canada geese are the exception. They are largely non-migratory and know the local lands well, often avoiding areas open to the early hunting designed to reduce their numbers. There is hope of moving these birds if the number of migrants mixed among them is high enough to set off a major panic when harassment begins. Again, it is best to do this after dark for it increases the chances the locals will not return, if repeated many nights in succession, and during the days as needed. Force all birds to leave during harassment. Any single bird that remains will serve as the nucleus for reforming of the flock if it stays on the pond, calls to passing geese, or if its family returns to find it, as is the normal pattern for the species.

Winter- December to Mid-February

Giant Canada geese and other large races can tolerate extended periods of sub-zero cold as long as deep snow doesn’t prevent them from feeding. Flocks spend days resting, making daily feeding flights to harvested suburban fields. In extreme cold, geese hunker down in the snow and nap all day to conserve energy. Plowed walks and parking lots absorb heat in the sun. Geese warm their toes, leaving copious droppings to track into building in exchange. Yet, these are great times to remove resident geese from corporate parks. If harassed with alarm calls and human disturbance in morning and evening over several days, they quickly find new, quiet places to live for the rest of the winter.  After a few weeks living elsewhere, those geese usually won’t come back, unless they nested on the original property in prior years.

February/March

Migrants start moving north in short hops that parallel the melting of snow on the landscape. Resident giant Canada geese begin fighting over breeding territories, small areas adjacent to water to be used later as nest sites. Pairs call back and forth at territorial boundaries and chase each other. Sexual behavior of neck-dipping and mating begins as soon as pairs have open water in which to carry out such activities. Once nesting territories are established, geese become much more difficult to move and will return day after day to try to reclaim the territories. They can only be moved off by continual harassment effort at the territory. Concentrate harassment on the female. If she leaves the male will go with her. If she stays, they both stay.

Mid-March to mid April

Nest construction and egg laying begin. Incubation by the female starts by the end of the month. Non-territorial birds shuffle to new locations to feed and rest because they are excluded from the usual sites by aggression of territorial birds. Non-territorial birds are fairly easy to scare away within hours of arrival at new locations. Territorial birds become increasingly difficult to move the longer they have defended a territory. Once the first eggs are laid, females subject to harassment will only show up at the nest for an hour every day or two to lay another egg, until the clutch of 5-6 eggs is complete. This is a bad time of year to initiate goose dispersal programs concerning nesting birds for it will be labor intensive and  unrewarding in terms of apparent results. Nest obstruction with branches helps get geese to leave.

Late April to mid May

Females remain on the nest 23.5 hours/day; male standing nearby to defend her. The farther into the 28 day incubation process the pair is, the more aggressive they become in defense of the eggs and nest, possibly injuring people on occasion. Addling eggs by oiling or shaking may extend the aggressive period if the pair doesn’t leave. Covering nests with sticks, etc. so the goose can’t incubate may cause abandonment or construction of another nest near the first, yet appears to reduce potential for aggression. Non-territorial transient birds may appear and disappear daily as they search for a new home.

Mid May to Mid June

Eggs hatch. Nests and territories are abandoned. Geese with goslings seek open grassy brood rearing areas with high quality foods. Young alternately feed and rest during the day. Parents and goslings are unable to fly during this period. They stay near the safety of water to which they can escape if people or predators approach. Flightless birds can’t move far if harassed. This is generally not a good time to initiate Alarm and Alert call usage on established resident birds since they can’t get out of hearing range, but it may be highly effective at preventing new broods of goslings taking up residence on ponds. Non-breeders and geese without young may retain flight ability until mid June and return to areas nesters had defended.

June 15 to July 1

Virtually all geese are flightless due to molt of primaries and tail feathers.  Non-breeding birds and those who failed at raising young often will have left for Hudson’s Bay on a molt migration and won’t return until September, so goose numbers appear to be down. Remaining birds can’t fly and gather near water for safety. Geese seek high quality foods to provide proteins needed for regrowth of flight feathers. This is a difficult time to move geese any distance. You can exclude them from pond access by use of low fencing. Since they can’t climb or fly over it, geese may go elsewhere to find water to enter when threatened. This is the only time of year where roundups of geese are possible. Using boats, people, and fencing, geese can be driven into small enclosures and captured.  Geese can then be translocated to other areas or euthanized with proper permits, thus guaranteeing that those geese will never return to the property in question.

July 1 to September

Goslings begin flying, and adults regain ability to fly. Fences are no longer an obstacle to water entry/egress. Resident birds gradually move goslings from brooding areas to their normal residence sites, eventually to be rejoined by non-breeders and returnees from molt migrations to Canada. Daytime activities center on feeding and napping on lawns near water. If your geese have been gone for a few weeks, this is a good time to start a fresh harassment program, put out alarm call units and prevent them from settling back into routine use of the property. If geese use the water as a night roost, use lasers or spotlights nightly to force them to fly away. Numbers should drop quickly and daytime goose problems may be reduced at the same time. Use of Alarm and Alert calls coupled with harassment helps improve success and also helps prevent recolonization of attractive sites by new geese.

Options for Physically Removing Geese and/or Reducing Goose Recruitment

The primary time for gathering and removing geese from a property is during the flightless period mid-June to early July. This is referred to as lethal removal and/or translocation. Cost in Ohio at present is about $25.00/bird removed plus $400-$-600 or more in set up and transportation costs to take the goslings to wildlife refuges.  This is a great option to use to remove final birds from properties treated with harassment and alarm calls. This removal method gets rid of the geese that have a long term habit of use of specific areas, makes it easier to prevent new geese from setting up housekeeping in future and keeps the property clear of geese.

Permits may be gained from the State DNR after demonstrating that you have attempted several methods to scare geese away or make the property less attractive to them. Normally the next step is to contact a wildlife control company to arrange a goose roundup. Two short pieces of plastic fence are set up as a large “V” leading into a small pen. These are rapidly erected on the day of the gathering. Meanwhile 6 – 8 people position themselves in such a manner that they gently push the geese- walking slowly so as not to scare the birds into running or escape behavior – towards the wide open end of the fencing. Once inside the fence geese are forced into the small pen and gathered by hand. Generally, goslings are sent to distant wildlife areas for release. The adult birds are normally euthanized to prevent them from returning to the roundup site when their feathers regrow. Meat from birds killed may be contributed to local food pantries if you can find volunteers to process it. Such meat may not be kept by the participants or contractors of the roundup.  Occasionally geese may be collected during the flighted period by using alpha-chlorolose treated bait and/or baited areas and cannon-nets. Special kill permits may also occasionally be issued for removal of a few specific geese that refuse to abandon an area following intense efforts at removal. These are particularly likely to by issued in sensitive areas such as airports where geese constitute a real and present danger to aircraft and human life.  Removal must follow federal guidelines for use of steel shot and other published restrictions.

Special urban hunting seasons when only resident geese are present have been used with limited success to reduce local goose numbers. These use liberal bag limits and encourage local golf courses and corporate properties to permit early morning restricted access hunting to eliminate problem geese.  Rapid and effective reductions in goose number can be made if hunters can shoot geese on the properties where they are causing damage   Local firearms discharge ordinances must be determined and followed or proper permits gained.

Reduction in recruitment is another way of saying preventing increase in the population through reproduction. Common methods used to prevent this population increase are egg addling and oiling- egg shaking, and or cooking oil sprayed on eggs to prevent them from developing and hatching. This action requires necessary permits from state and federal wildlife authorities before it may be begun. Over the long term, this process has been successful in reducing local populations if nests are relatively easy to find and all eggs are oiled, boiled, addled or replaced with wooden eggs.  At least one study has found circumstantial evidence that this method may lead to increased aggression by nesting adults by prolonging incubation (Whitford 2004). Another effective way to reduce gosling hatching and nest success is by nest obstruction- putting obstacles in the nest that prevent further egg laying and incubation. Large sticks, rocks, even heavy plastic owl models normally used to scare birds can be put in nests that have 2-3 eggs in them. We experienced 100% success nest abandonment and prevention of recruitment in our study (Whitford 2004).

Options for Habitat Alteration to Reduce Site Attractiveness for Geese

Since it is the presence of manicured grasses in association with water that are the primary attraction that brings passing geese to ones property, it makes sense that elimination of either immediately reduces the attraction from the goose’s perspective. One can also make it more difficult for the geese to move from one to the other, and thus discourage use of the property. The latter may be accomplished by erecting excluding devices such as low fencing around ponds, preventing adult and gosling entry/exit during brood rearing and flightless periods. This can be extended to year-round exclusion from the water by construction of grids of thin wire or fishing line 1 meter (3 feet) above the water’s surface to prevent flying entry to the pond.

Among the easiest ways to reduce attractiveness of corporate lawns for geese is to reduce the frequency of mowing and fertilizing. Grass that is 5-6 inches in length is much lower in protein and harder to digest than 1-3 inch grass and geese avoid eating it, if possible. There are also some grasses that have proven to be less palatable than others. Avoid Kentucky Blue Brass plantings near water, for geese are very fond of this. Short-term sprays exist which can make grasses unpalatable to geese.  The most common forms are modified grape-seed flavorings whose active ingredient is methyl anthranilate, such as GooseChase, which can be sprayed on the grass to discourage geese from eating it, and hopefully encourage them to go elsewhere to.  There has also been use of spray agents that cause geese to become ill following eating of treated grass, chemicals such as methio-carb in hopes they will avoid that area in future. Flavor aversion based chemicals are available from Bird-X, Inc. in Chicago and several other suppliers listed in the back of Smith et al 1999.  Drawbacks to any of these products include the relatively high cost per acre for treatment; the need for sprayers and personnel to apply them; and the fact that they need to be reapplied after rains and mowing.

Geese can be discouraged from use of ponds and lawns in other ways. The Hershey Corporation in Hershey, Pennsylvania planted extensive prairie grasses on its new campus. The tall grasses and flowering forbes are taller than the geese and extend right down to the water sides of the many ponds on the property. Geese have not colonized the area and the company has reported extensive savings on lawn care as a side benefit. The same can be done on a lesser scale by planting a 30 foot width of tall grasses or dense tall perennial flowers or shrubs around the margins of ponds. Dense tall grasses or other vegetation prevents goose movement through it, for they become nervous if they can’t see over the tops of the vegetation or at least 10 meters (33 feet) around themselves. The sense is that they consider such cover to hide potential predators and they can’t see far enough into/over it to have warning for escape.

Not all habitat modifications need reduce aesthetics of the property or use of facilities by employees. Addition of heavily used walking/biking/jogging paths around ponds on corporate or municipal parks has been implicated as a means to keep geese from adopting these sites for loafing and feeding (Whitford 2002). In such cases design should have the pond/lake shoreline be relatively smooth and free from points projecting out into the water.  Most importantly, paths should follow the margins of the water closely at a constant distance of 10-14 meters (33-45 ft) from the water’s edge. This is the preferred resting distance from water for Canada geese and also incorporates the fact that geese respond to human approach by movement away or assumption of alert postures when approached to closer than 9 meters (30 ft). The combination of distance to water, goose avoidance patterns related to humans, and high human traffic levels were hypothesized to explain absence of geese from areas where these conditions occurred in selected parks in Minnesota and Wisconsin. A path at the proper distance from large ponds coupled with encouragement of employee use for walking, using staggered break timing, can prevent goose problems while potentially improving employee health, alertness and morale.

Options of Techniques for Dispersal of Canada geese

Most options for dispersal of Canada geese have been covered in the previously mentioned “Managing Canada Geese in Urban Environments (Smith et al 1999). The most common methods and their relative merits are summarized in the next few paragraphs. In addition I shall address new techniques not in the literature at the time the manual was written, several of which appear to offer real potential for moving problem geese.

First and foremost, I feel compelled to state the obvious before being the rest of the discussion. To effectively remove geese from corporate and municipal park ponds and lakes all supplemental feeding by the public must be stopped. Geese won’t go away if they are getting daily handouts of bread and corn!! That said, let us continue.

Visual scaring devices:

These are things such as black or orange plastic flags attached to fence posts to blow in the wind, reflective mylar tape strung around ponds and on fences, eyespot balloons and/or kites mounted on long poles, scare crows and flashing strobe lights. Flags are inexpensive, work only when wind is present, and have been found to be best at preventing geese unfamiliar with the area from landing. Scarecrows, eyespot balloons and reflective mylar balloons have been reported to have some short term success, but fail rapidly if geese return to the same site day after day. These techniques are cheap to employ and relatively successful at preventing new geese from establishing themselves in the short term. Floating alligators and alligator heads with glittering eyes have been reported to scare geese away from, or prevent geese from landing on ponds at least part of the time.

The newest reported forms of visual scaring devices consist of the use of lasers (Blackwell, et al. 2002) or spotlights to disturb geese roosting on the water of large ponds. Such night roosts often attract hundreds of geese that either sleep on the water or shoreline. They leave during the day to eat and rest on nearby properties, so removing them from the night roost tends to reduce problems on close properties as well. Lasers used may cost several hundred to several thousand dollars. Powerful battery powered spotlights that can be bought at sporting goods stores generally sell for $75-100. Both are best used just after sunset and several more times through the night. Lights are swept over the water and focused on individual birds until virtually all geese have flown away.  In as little as a week, reports have indicated major success at having geese shift to new night roosting sites when using these techniques. They are a bit labor intensive, and thus somewhat costly but have good potential in night roosting situations. Unfortunately, they can’t be applied to daylight concentrations of geese with any degree of success.

Trained Dogs, Falcons, Swans, and Radio-controlled planes and boats:

All these methods can be very successful at removing transient geese, and migrants as long as they are available on demand on short notice. They all require specially trained personnel and often a major investment or commitment to continued control efforts. Trained Border Collies may run from hundreds to thousands of dollars to purchase, and require someone to feed and care for them and direct their activities. Most commonly a wildlife control service is hired to bring dogs out regularly to chase away geese. In the Columbus, Ohio, area current charges I’m aware of are roughly $50.00 per visit and a minimum of a week or two of daily visits is often required. At local parks where I have watched the process, geese rapidly came to recognize the trucks the dogs arrived in, and anticipated the time of arrival since the operators often followed a fixed route in chasing geese. Geese did leave the parks- but invariably returned 20-30 minutes after the dogs had been taken to the next job if they were long-term residents.  In such cases, goose removal efforts are ineffectual, long term, and expensive.

The model planes and boats are used to move geese from larger bodies of water where dogs generally can’t reach them. Cost would be comparable to those for the use of dog services/visit. The use of Mute Swans is generally is considered ineffectual at scaring geese away and may cause more problems than the geese at times given their greater size and more aggressive nature.

Noise making devices:

A wide range of devices have been tried as means to scare geese over the past 50 years, particularly in agricultural fields. Sirens, airhorns and whistles have been used effectively on migrant geese either as vehicle mounted or hand-held units but were all considered to lose effectiveness through habituation (failure of geese to respond after prolonged use) when used against resident birds. Firing blanks from a handgun, use of fireworks, or use of bangers, whistle bombs, screamer and cracker shells fired from other firearms has generally had good results with transient geese. The greatest problem with this approach is that it is suited primarily for rural use. Especially since 9/11 and a spate of highly publicized work place killings, gunshots are not considered suitable for the corporate park. Besides, most municipalities have ordinances against discharge of firearms and explosive devices, and there is always a fire danger associated with these explosive shells in dry conditions.

Propane cannons and exploders are large, relatively expensive noise making devices created just after World War II, but still in use today in agricultural settings. They detonate carbide or propane gas at timed intervals to produce a loud ‘boom.”  Transient and newly arrived migrant geese generally respond to the sound by moving to other fields to feed- at least for the first few weeks of use. A single cannon can provide coverage for 10-50 acres of field depending on condition and topography of the field. Used correctly, they are very effect for short term crop protection- but unlikely to be popular on a corporate campus or in a city park, or golf course.

Ultrasonic sound devices have been offered for bird control for some years, but the rapid energy loss of high frequency sound makes it unable to carry over significant distances. Ultrasound repeller tests of a commercially available repeller unit in 2001 on a golf green occupied by Canada geese evidenced no response beyond 6–7 feet in multiple tests of goslings and adults (Whitford unpublished data).

Distress/Alarm/Alert Calls:

Alarm and Alert calls are among the most recent sound production devices to be widely applied to goose problems, though they were first tested in the early 1980’s, (Whitford 1987, Mott and Timbrook 1988). Complete descriptions of call form of Alarm and Alert calls and associated behaviors of giant Canada geese, B. c, maxima, have been made previously (Whitford 1987, 1998). The primary distinction between “distress calls” marketed for goose dispersal since the 1980’s and the Alarm and Alert call recently released deal with their manner of recording and nature of the sounds themselves. The distress calls were produced by directly holding a goose and subjecting it to physical abuse by dunking it up and down in a tub of water. Calls made during this handling were recorded and dubbed “distress calls”. They are not naturally part of the repertoire of the species, and were unintentionally highly modified in form and frequency by the action of the people handling the bird. In contrast, the current Alarm and Alert Calls released by Bird-X on the Goosebuster Unit, were recorded in the field under natural conditions and are part of the normal call collection of the giant Canada goose.  Both calls elicit fairly predictable instinctive alert and/or escape responses from geese hearing playback of the calls (Whitford 1987). To date, only use of the Alarm and Alert call playback system has shown evidence of consistently successful dispersal of geese, and additionally offers evidence of preventing re-colonization of areas following resident geese dispersal, removal by transplanting, or lethal methods (Whitford 2004).

The major research work supporting the conclusions above is summarized in the following paragraphs. The research was conducted on a corporate park in Dayton, Ohio, February to August 2002. Data collection, record keeping, and goose harassment activities relied almost exclusively on assistance from the head of security for the central corporate property on the study site.  In granting study permission, the corporate legal office restricted use of the company’s name, precise location, and Security Director’s name, in any publications generated, so they may not be used here. Even though I could not use the corporate name in publications, I chose to proceed with the study because it provided the opportunity to simultaneously address several important questions: 1) Could geese be moved off established territories by our combination of techniques after breeding season began? 2) Could the geese be taught to avoid the central campus complex if no effort was permitted to displace them from adjacent properties? 3) Would call playback alone continue to keep geese away from the property once daily harassment efforts ceased? 4) And, finally, could the harassment techniques be effective at removing geese when the majority were to be carried out by an untrained, non-wildlife specialist, acting as a research volunteer, one who had many other corporate duties. I viewed the latter aspect as more or less a real world test application of the alarm and alert call units in the hands of the people who would need to utilize them for goose removal operations on most corporate properties.

The study site was a 24.2 ha (60 acre) corporate park with .2 ha (1/2 acre) pond, soccer and baseball fields, 6 buildings, and paved parking facilities for 1400 cars. It was situated between two other properties: 1) a 12 ha (29.5 acre) corporate park with .5 ha (1.2 acre) pond, landscaped and grassy areas and parking for 200 cars, roughly 120 m (400 ft) across undeveloped land from the study site; 2) an apartment complex with >1 ha (2.5 acre) manmade lake lying just across the highway from the primary corporate campus. Resident geese used all three properties at the onset of the study. Roughly 85-100 were present at any one time on the central property. Another 80-140 used the adjacent properties for daily activities and night roosting. Nest and egg addling records indicated 43-45 active nests annually for the previous 5 years on the primary campus. Goose numbers required daily walk sweeping, annual re-sodding of lawns near pond margins, and caused employee complaints about extensive dropping contamination of the baseball and soccer fields, parking lots, and entryways. Facilities records for 2001 indicated 32 reports of aggression to humans, including two cases of injury requiring hospital treatment.

Alarm and Alert call playback used digitized forms of calls originally recorded from wild and captive giant Canada in 1981 (Whitford 1987). These calls were copied and digitally altered, producing 3 slightly different call series. The resulting calls were then rerecorded onto microchips of three “Goosebuster” units from Bird-X, Inc., Chicago IL 60607, and those units were used for this study. The digital adjustment and microchip production were designed to alter goose perception of the sound and to foster the impression that several individuals were giving alarm or alert calls. Call units play up to 4 different call series, mixes of varied alarm and/or alert calls, in randomized sequence, one series via each of four dispersed speakers, each time playback is initiated.  Playback units had three internal timer settings, “test,” “short,” and “long,” providing the option of call playback at randomized times within base intervals of 1-3, 5-10, or 10-20 min, respectively. The volume controls for all units were set to make call playback consistent with natural goose alarm call volume, and to avoid disturbing employees in the adjacent buildings or attracting attention to the call units. Call playback and harassment started 26 February, 2002 and continued until 14 May 2002. Thereafter only call playback was used until the study ended 15 August. The study began roughly three weeks after breeding territories were established.  Since many geese present were nesting in territories they had used in previous years, I expected this to make these geese very difficult to permanently disperse with non-lethal methods.

Human harassment consisted of one person chasing geese on foot and waving their arms to encourage geese to fly. Geese were chased until they left the property entirely, even if they landed at multiple locations before leaving. In the study design, a combination of persistent pursuit and zero tolerance of geese on the grounds was considered essential in getting geese to abandon the site for the long term. To discourage nesting on the campus, once egg laying began we placed heavy owl decoys, sticks, or mylar balloons directly in nests to prevent further laying or incubation. Geese either abandoned the area or constructed another nest and began laying again. Evaluation of success of the alarm/alert calls and harassment technique was to be based on estimates of geese/hours/day on the property, dropping counts/100 m (109 yd) on a fixed set of 10 100 m (109 yd) segments of sidewalk, and reports of goose aggression, and injury to employees between the year before and during the study.

With Alarm/alert call playback coupled with our physical harassment estimates of 1600-1800 goose hours per day on the property before we began, dropped to fewer than 150 hrs/day by the third week of harassment, declining to 0 hrs/day by 14 May (Fig 2).

Fig. 2  Reduction in total goose hours per day during Alarm/Alert call and harassment study.

Goose droppings per 100 m of walks, fell significantly F (3,24) = 30.048, P< 0.0001, from a mean of 195.7 to 3.28 per 100 m between 26 February and the next counts on 24 March, a 97.88 % reduction Fig. 3).

Fig 3.  Decrease in goose droppings per 100 meter of walk during Alarm/Alert call and harassment study.

Pairs attempting to nest on the property declined to 19 in 2002, and all nests were abandoned before incubation began. There were no reports of goose aggression or injury to humans from geese in the 2002 nesting season, versus 32 and 2 reports of these problems, respectively, in 2001 (Figure 4).

Fig 4. Comparison of reported goose aggression and/or injuries to employees before (2001) and during (2002) the study.

In the long run, the combination of call playback and harassment proved successful at eliminating all geese from the property, even though geese remained on the immediately adjacent properties. All non-paired, non-territorial geese and half the original pairs quickly abandoned the property in the first two weeks, bringing about a rapid decline in daily harassment.  Geese did not return to use of the study campus once human harassment efforts ended 14 May, implying that learning, association, and/or sporadic call playback were adequate to prevent past resident geese from reestablishing themselves, or new geese from beginning to use the site during the 14 May to 15 August period when only call playback units were in use. Together, this evidence supported the hypothesis that call playback alone would be sufficient to keep the campus goose-free once initial geese were removed. Last, but still of importance, results indicated that an untrained but willing volunteer without wildlife control experience could perform much of the needed harassment at levels adequate to make the goose dispersal project succeed.

Reduction of goose damage to lawns was evident in that new sod required to be planted annually in 2000 and 2001 around the pond and building entrances remained dense and healthy in 2002. Additionally, the corporation also saved expenses associated with daily cleaning of walks and internal hallways that was required prior to the study. These savings in labor and costs, if comparable at other problem sites, should more than offset employee time and expense of the goose call playback and harassment efforts for a removal project such as this.

As a final comment, it should be noted that no single non-lethal dispersal method can be expected to be successful at goose removal 100 % of the time.  Combining  and applying several dispersal methods simultaneously virtually always improves the probability of getting all geese to leave the desired property and stay gone. As yet, only the use of Alarm/Alert call playback has been demonstrated to have real potential in preventing recolonization of attractive sites by new geese once the original geese have been dispersed, translocated, or lethally removed. Therefore these devices appear to  offer the best option for keeping the property clear of geese without additional human effort once the original problem geese are gone.

LITERATURE CITED

Alge, T. L.,  Airport bird threat in North America from large  flocking birds, (geese) as viewed by an engine manufacturer. Proceedings of the Joint Birdstrike Committee- USA/Canada meeting. Vancouver B. C. p11-22.

Blackwell, B. F., G. E. Bernhardt, and R. A. Dolbeer. 2002. Lasers as nonlethal avian repellents. J. Wildl. Manage. 66(1):250-258.

Cooper, J. A., and T. Keefe.  1997.  Urban Canada goose management : policies and procedures. Transactions of the North American Wildlife and Natural Resources Conference. 62:412-430.

Mott, D. F. and S. K. Timbrook. 1988.Alleviating nuisance Canada goose problems with acoustical stimuli. Proc. Vertebr. Pest Conf. (A. C. Crabb and R. E. Marsh, Eds)          13:301-305.

Smith, A. E., S. R. Craven, and P. D. Curtis. 1999. Managing Canada geese in urban environments. Jack Berryman Institute Publication 16, and Cornell University Cooperative Extension, Ithaca, N.Y.

Whitford, P. C.  1987.  Vocal and visual communication and other social behavior in Canada geese (Branta candensis maxima). Dissertation. Univ. of Wisconsin-Milwaukee. 420 p.

Whitford, P. C. 1998. Vocal and visual communication of giant Canada geese. Pages 375-386 in D. H. Rusch, M. D. Samuel, D. D. Humburg, and B. D. Sullivan, eds. Biology and management of Canada geese. Proc. Int. Canada Goose Symposium., Milwaukee, Wis.

Whitford, P. C.  2002 . Shoreline characteristics of urban lakes as a factor in nuisance goose problems. The Passenger Pigeon. Vol. 64:4:271-281.

Whitford,P. C.  2004. Use of Alarm/Alert call playback and human harassment to end Canada goose problems at an Ohio business park. Proceedings of the Tenth Wildlife Damage Management Conference. P 245-255.

line