James A. Cooper
Associate Professor of Wildlife
Department of Fisheries and Wildlife
University of Minnesota
Every fall duck blind conversation, over hot coffee and sandwiches, invariably drifts to stories from the "good old days". Memories of mallard flights that seemed endless, blue bills back in the decoys before the birds bagged from the last flock could be retrieved, and the sound of so many wings that speaking was useless. Unfortunately, duck hunters with these memories grow older each year. Young hunters cannot imagine selecting drakes only, limiting the shoot to one gun per flock, and being home by 8 AM with a full bag. Goose pit conversations are similar, but with a difference: the "good old days" were last weekend, or last season, or the season before. While ducks have declined, geese, particular the Canada Goose have flourished. Where geese were once so rare that the lucky hunter who bagged one often got his picture in the local paper, now the birds are abundant and in some cases, even considered a nuisance. An examination of the factors leading to these changes not only gives us insight into goose management, but also leads to an understanding of how human activities can affected wildlife.
The Canada Goose, easily identified by its white cheek-patches and black head and neck, is the most wide-spread and abundant North American goose. It occurs in every state and province sometime during the year. The species breeds from Labrador to Alaska, south to California, and eastward to Georgia. In winter, Canada geese may be found from southeastern Alaska to Hawaii and Mexico, and from Massachusetts to Florida. Current surveys indicate that the species exceeds 3 million individuals, and that its southern breeding range continues to expand.
The Canada Goose shows great variation in body size, and regional differences in plumage, bill shape, and call. The smallest birds, slightly larger than a Mallard at 4 pounds, breed in the far north and winter in the far south. The largest birds, such as those breeding in Minnesota, average 12 to 14 pounds with some individuals weighing up to 18 pounds. Intermediate types are found in between. Eastern range birds, whether small or large, tend to have light belly feathers and buff-brown back, tail, and wing feathers, with few showing white rings at the base of the neck. As one travels westward, belly feathers become progressively darker. The darkest birds are found breeding in the humid coastal climates. Some, notably the coastal Canadian and Alaskan birds, have distinct white rings at the base of the neck. These rings may be up to 1 to 1.5 inches in width. The smaller geese typically have short, heavy bills and yelping-like calls similar to the bark of a small dog, while the large birds have proportional larger and more slender bills, and deep, resonating honks.
Several authorities have divided the species into 8 to 36+ "races" or "subspecies". Whether the situation is one of distinct races, or a gradual change in body size and characteristics, is still open to scientific debate. Perhaps it would be best for now, to use a "small" (up to 6 pounds), "medium" (6 to 10 pounds), and "large" (greater than 10 pounds) approach.
We do not know how abundant Canada geese were in pre-european settlement times, but the numerous accounts given by early explorers and the place names of lakes ( there are 36 "Goose Lakes" in Minnesota), suggests that the bird was widespread and common. Yet, by the beginning of this century, breeding geese were lost from the prairies and woodlands stretching from Alberta to the Maine and southward along the east slope of the Rockies to Kansas and then eastward to Tennessee and the Carolinas. In Minnesota, the species declined dramatically during the 1850 to 1900 period when both subsistence and market hunting peaked. The last wild Canada geese breeding in Minnesota were found at Heron Lake in 1933. And as we now know, the early spring return of fat, breeding-season ready birds, and their easily detected calls, made the species both an easily located and prized source of fresh meat and eggs for hungry settlers and natives. This, combined with the fact that Canada geese return to the same marshes each season to nest, resulted in the extirpated of the species from much of its southern range.
While the wild birds were declining, small numbers of geese were taken captive from local wild flocks for use as live hunting decoys. When the use of live decoys was banned by the Migratory Bird Treaty in 1916, some flocks were retained by aviculturists. Because the bird readily breeds in captivity, these flocks provided a source for release in unoccupied habitats, beginning in the 1920's. By the 1950's, Canada Goose re-establishment programs were underway by the U. S. Fish and Wildlife Service and a host of state wildlife departments. The Minnesota DNR was a leader in this effort, along with private sportsmen's clubs, and individuals. Currently, restored large Canadas are common nesters in the prairie and eastern Canadian provinces, and the northern states.
Whether they are large or small, Canada geese share numerous traits that make them fascinating and relatively easy to manage. The bird is one of the earliest spring migrants, and first among the midwest waterfowl to return to the breeding grounds. Pairs may be seen standing on the ice next to last year's frozen nest mounds by early March. Eggs are laid as soon as there is open water for mating and snow-free nest sites. It is not unusual for the birds to continue nesting in spite of temperatures as low as 0 F and snowfalls up to 10 inches. Nesting in Minnesota begins in mid-March and in the northern most regions, in mid-June. The goose (the female) builds the nest and incubates the eggs without direct aid from the gander (the male). The male, however, guards the female from disturbance by other mature pairs and assists the goose in protecting the eggs, and later, the goslings. So important is his role, there are no cases cited where a female has successfully nested after the death of her mate. Pair bonding takes place in spring among young geese, one or two years of age. Once formed, the pair remains steadfast until the death of one of the members. Contrary to popular believe, the survivor normally forms a new bond the following spring, and nests.
Nests are typically built on isolated sites separated from adjacent dry land by a moat of open water. Natural or human-made islands, muskrat or beaver lodges, or sedge hummocks are frequently used. A clutch of 5-6 white eggs is laid at a rate of approximately one egg every 36 hours. The first eggs are buried in the nest materials which consists of whatever fine materials are available at the site. By the completion of laying, the goose has pulled fine, down feathers from her belly area and has incorporated them in the nest. This gray down blanket is used to cover the eggs in her absence, reducing egg cooling by 50% and the likelihood that a passing predator will find the eggs. The female incubates from 97 to 98% of the day and takes but 1 or 2 brief, 10-15 minute recesses from incubation. Time off the nest is divided almost equally into feeding, bathing, and preening (rearranging and dressing her feathers with oil from her oil gland). The eggs hatch over a 24-hour period, starting on the 26th day after the last egg is laid. The young remain in the nest and are brooded on the 27th day, with nest departure normally occurring on the morning of the 28th day.
Canada Goose nest success typically ranges from 60 to 80%. Four goslings are hatched per successful nest. Nests are lost to mammalian (coyote, fox, skunk, and raccoon) and avian predators (crow, raven, and large gulls), to flooding, and to desertion. The latter is seldom due to human disturbance, but rather to interference by adjacent territorial pairs.
Once the young have hatched, the family abandons the nest site and travels, sometimes 5 or more miles, to a suitable brood-rearing site. Sites used by geese with their young are typically large (more than 10 acres) open-water wetlands and lakes, or slow moving rivers. Common characteristics of brood concentration sites, are clean (no driftwood or other debris) shorelines with low grasses, free of thick shrubs. Here, families of geese join together to graze on rapidly growing grasses and forbs. Like all grazing animals, geese have developed flocking (herding) behaviors, where the "many eyes mean better predator detection" and "better to be 1 of 100 than 1 of 1 if a predator attacks" principles apply. In a nutshell, Canada geese select open, grassy shorelines where visibility is good, food is abundant, and predator escape cover (open water) is only a short run away.
Five weeks after the young hatch, the female loses her flight feathers and enters the molt period. The male molts 4 to 10 days after his mate. Both remain flightless until the young can fly, at 9 to 10 weeks of age. Because of the energy and nutrients needed to replace flight feathers and for the gosling to grow from fist-sized to nearly full grown geese in less than 10 weeks, large quantities of forage must be consumed. If the source is an agriculture crop or a golf course, the resulting damage done to these areas and the goose droppings are frequently unwanted.
Once on the wing again, in late July in Minnesota, the birds remain in families and the family groups that molted together remain together. These "subflocks" feed in the same fields and roost on the same open-shoreline lakes until they migrate. Moreover, these "subflocks" appear to remain intact during migration and on the wintering grounds. In this manner, the young geese learn the local environment and migratory routes from their parents, or if both parents die, from the other adult members of the "subflock". This non-random movement behavior explains why geese stop at specific spots each year, and why wildlife managers have been able to provide for increasing numbers of geese by improving food resources along the migration routes.
In fall, when a strong, high air pressure system follows a well developed low system, a cold front will sweep across the plains, leaving a blanket of snow behind. If the snow is deep enough (5 inches or more), the geese will wait out the storm, and when the sky clears and the wind is strong from the northwest, they will migrate south. Records from banded geese, particularly neckbanded ones, indicate that the migration flight is non-stop for 600 miles or so. During mild winters with little snow, such as this winter, many birds do not migrate. Presumably, this behavior permits those pairs to be the first to return and secure their breeding territories. In spring, the situation is the same except that migrations north occurs when a strong low follows a high pressure system.
Winter is a relatively quiet time for Canada geese; families and subflocks continue to squabble over the best feeding and roosting sites, but once patterns are established, they change little until late winter. The birds normally fly from roosting to feeding sites about 8AM, feed and return within an hour or two, and preen and sleep until about 3PM. They then fly again to the feeding areas and return to the water to roost at dusk. During periods of extreme cold, 10F or below, when the energy gained from feeding is less than that expended in securing food, most birds remain at the roost. During these times, energy is conserved by sitting on the snow, pulling the feet up into the flank feathers, and placing the bill under the scapular feathers on the back. While it is easy to feel sorry for the birds during these frigid times, healthy geese are capable of going 30 or more days without food, and can migrate south as late as mid-January if deep snow covers the food resource.
Canada geese migrate only as far south as needed to find an environment with open water, food resources, and temperatures suitable to their body size. Small geese with a greater surface area-body weight ratio cannot endure cold as well as larger birds. These birds winter in the deep south, whereas large birds stay well within the snowbelt.
The challenges facing midwest wildlife managers are primarily problems associated with goose concentrations and harvest regulation. Major management issues are short-stopping, crop damages at concentration spots, maintaining northern breeding populations with harvest quotas, and management of growing re-established resident flocks in rural and urban areas.
Short-stopping is a label used for an ongoing debate. This debate is over whether the additional food resources provided at refuges in the northern states has caused fewer birds to migrate to states south of Illinois and Missouri, or whether excessive past hunting of the geese that wintered in these states is the cause of fewer Canada geese going there. There is little question that the amount of waste grain available to the birds has increased with agricultural expansion. There is also evidence that groups of geese that consistently wintered in the deep south were shot at higher rates than those staying further north. Currently, research is being done to identify groups that winter in the south, with the goal of encouraging the growth of these groups.
Because geese pass on the migratory routes to their young, those that find safe stops, such as refuges, have better survival. Therefore, more geese use these refuges each year. To the goose hunter and watcher these places, such as Horicon Marsh in Wisconsin where more than one quarter million Canada geese stop in fall, are truly a national treasure. But to the farmer with crops adjacent the refuge, the growing population means more crop damage and less income. Programs to get birds to move elsewhere, such as reducing refuge foods and open water, and by harassing the birds, have had limited success. Probably the long-term solution is to allow additional harvest and encourage farmers to market hunting opportunties. Such a mix of private and public hunting is found at Lac Qui Parle in western Minnesota where 80,000 or more birds stop in fall.
While small and medium size geese breeding in the arctic and subarctic have increased over the past decades, a recent series of cold, late springs has reduced their nest success. To compensate for lower production, managers have restricted bag limits and season kill quotas. Concurrently, re-established large geese, continue to increase at rates up to 200% every 3 years. These local, large Canadas depredate farmers crops, particular soybeans during the brood-rearing period, and thus, there is added pressure to have special goose hunts to limit population growth. The challenge is one of protecting migrants while increasing the take of local geese. Current research is aimed at solving this dilemma.
Canada geese have been released in urban areas for over 4 decades. Initially, no one knew if the species would survive. But, the bird seemed a welcome addition because of the beauty of its flights, and a call that many associated with wilderness. Our hindsight tells us that not only was the Canada Goose able to survive, but its numbers in urban areas have exploded in the past 10 years. For example, the Twin Cities population has grown from less than 500 in 1968 to an excess of 15,000 in 1986. The reason for this, is simple: the large Canada is adapted to the city environment. Our mowed lake shores and golf courses provide a super abundance of brood-rearing habitat, there are fewer predators, and the bird is not affected by our presence. Unfortunately, geese are primarily grazers and the forage they eat is relatively low in quality. This means that to meet their needs, the birds have to eat and digest large quantities of grass. What goes in, must come out, and if the output is on a golf green, swimming beach, or picnic area, the human users usually complain. If it was only one pair of geese, the nuisance would probably be tolerated. But remember, geese are social animals that occur in groups, and 100 or more birds can really mess up a beach--literally.
The solution to too many geese in cities is a complicated one. Because city goose problems are a new phenomenon, there has been little research done. We know that populations can be controlled by increasing mortality or decreasing reproduction, but just what is biologically and economically effective and socially acceptable is unclear. Recent research has been aimed at testing translocation, that is, reducing numbers by capturing and shipping flightless adults and young elsewhere. Results of these experiments have shown that populations can be reduced as much as 90% in three years. However, the technique is self-limiting. Other states, particularly, southern states are willing to take the birds now, but what can be done when these folks meet their goose restoration goals and no longer want additional birds? Research is needed to test the effectiveness of additional hunting in limiting city populations, egg destruction, and perhaps the feasibility of using the excess production for human consumption.
In summary, the Canada Goose is a gem of a bird. It is beautifully adapted to human-altered, as well as, wilderness settings. The animal has a complex social system with many attributes that we find admirable. It is held in high esteem by hunters and non-hunters alike. But when it damages crops, golf greens, gardens, etc., or where it endangers human life at airports, intensive management programs will be needed.