Giant Canada Geese in the Wingra Watershed: A Preliminary Report
Jim Lorman, Edgewood College and Friends of Lake Wingra
May 27, 2003

Urban populations the giant Canada goose (Branta canadensis maxima) have increased dramatically in recent decades throughout North America, creating frequent goose-human conflicts (Smith et al. 1999). The giant Canada goose, one of 11 recognized subspecies of geese in North America, was thought to be extinct in the first half of the 20th century; but remnant populations were discovered and widely introduced into new areas in the 1960s. Populations of B. canadensis maxima in the U.S. recovered dramatically as a result of protection and recovery efforts, increasing from an estimated 55,000 in 1965 to 2 million three decades later and 4 million in 2002 (about 1.5 million in the Mississippi flyway alone) (Rusch et al. 1996; Schmidt 2003; Leafloor 2003).

During this time of rapid population growth, giant Canada geese have become increasingly adapted to urban and suburban environments, often breeding in cities and staying in or near them year-around, even in northern states like Wisconsin. Migrating populations (which themselves tend to winter further north each year) often join these resident urban populations, which apparently serve as “decoys” that attract migrants to urban areas occupied by resident geese.

Problems associated with increased numbers of urban geese include

• Large quantities of feces on lawns, playgrounds, beach areas, etc.
• Damage to turf and increased erosion
• Increased nutrient runoff and resulting lake eutrophication
• Transmission of diseases to other animals (potentially including humans)
• Aggressive attacks on people, especially during the nesting season
• Airplane crashes resulting from encounters in the air

In the Madison area, including the Lake Wingra watershed, the numbers of resident and wintering geese have increased dramatically since the 1980s. Madison area Audubon Society Christmas bird counts (taken annually by volunteers in a 15 mile diameter area centered on the state Capitol building) increased from just a few for each hour of observation prior to 1990 to commonly 20-30 per hour since that time (Figure 1). In December 2002, more than 20,000 geese were observed during the Madison Audubon Christmas bird count (more than 80 per hour of observation).

The number of resident (locally nesting) giant Canada geese have also increased during this time: in the summer of 2002, there were an estimated 23 adult geese resident in Vilas Park, producing about 33 young (Lorman 2003). During the fall (late October through the first hard winter freeze), migrating geese co-mingle with these resident geese. Counts made since 1991 show that 100-700 geese are regularly present in Vilas Park during this migrating season (Figure 2).

Counts of geese in different areas of Vilas Park (Figure 3) have been made by Edgewood students since fall of 2001. In the fall and winter (Figure 4), the largest number of geese occur in the playing fields (Zone 2). Geese are more evenly distributed throughout the park in spring and summer, with high number on the island and along the lake shoreline (Figure 5).

The feces left by these geese is a nuisance for park users and probably contributes to contamination of the lake. An average of 12 g/m2, or about 100 lbs per acre, dry weight feces was determined by sampling in November 2002 within the grassy areas of Vilas Park heavily populated by geese (Lorman 2003). This is equivalent to about 600 lbs per acre wet (as collected) weight, and more than three times this amount has been measured in some areas of the park.

As a result of concerns raised about urban geese, the Madison City Council created an Ad Hoc Committee on Integrated Waterfowl Management in 2002. The recommendations of this committee are:

1. Development and implementation a scientific protocol for the documentation of bird counts, feces quantity, locations, numbers of nesting pairs, and survival rates of hatchlings.
2. Facilitation by the Parks Division of discussions on strategies for urban waterfowl management with adjoining communities.
3. Development and distribution of an informational brochure.
4. Trial use of herding dogs at the Yahara Hills Golf Course.
5. Consideration of reproductive control techniques, such as oiling or addling eggs.
6. Consideration of modifications to shoreline habitats.

Preliminary management recommendations for Vilas Park
Friends of Lake Wingra recommends that management of Canada geese in Vilas Park be aimed at reducing the goose population to about 20 birds. Surveys indicate that people do not generally consider Canada geese populations of less than 20-25 individuals to be a nuisance in a particular location (park, golf course, etc.). A population this small is also not likely to do significant landscape damage or contribute significantly to health or water quality problems, yet it maintains the wildlife value provided by these magnificent birds.

Giant Canada geese have been successfully managed at sites throughout the country with programs approved by the Humane Society and other national wildlife protection organizations. These programs include:

1. Educational efforts and ordinance changes that discourage the feeding of geese
2. Landscape modification, particularly the creation of shoreline vegetation buffers
3. Use of trained dogs to encourage geese to leave the site
4. Egg oiling during the first two weeks of incubation in the spring

We recommend that the City of Madison Parks Division work with the public, through Friends of Lake Wingra and local neighborhood organizations, to create a detailed plan to implement these techniques as needed over the next 5 years (and in the order listed above) to limit the population to 20 birds throughout the year in Vilas Park. We also recommend that the impact of management efforts be assessed through continued monitoring of geese numbers and distribution patterns. These efforts should be consistent with, and support, the citywide management efforts already initiated by the Parks Division; and they should be applied to other locations within the Wingra watershed (e.g., Wingra Park; Wingra Creek) where geese problems may arise.

References
Ad Hoc Committee on Integrated Waterfowl Management. 2002. Report to Madison Common Council dated May 8, 2002. I.D. #30851.

Leafloor, J. 2003. Canada goose management in the Mississippi flyway. 2003 International Canada Goose Symposium, Madison, Wisconsin.

Lorman, J. G. 2003. Data collected by Edgewood College students.

Rusch, D.H., J.C. Wood, and G.G. Zenner. 1996. The dilemma of giant Canada goose management. Pages 72-78 in Ratti, J. (ed.). Proceedings of the 7th International Waterfowl Symposium. February 4-6, 1996, Memphis, Tennessee.

Schmidt, P. 2003. Canada geese in North America: past successes and future challenges. 2003 International Canada Goose Symposium, Madison, Wisconsin.

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.