Waterfowl using the Central Flyway congregate on staging lakes before fall migration. The Quill lakes area of Saskatchewan Province, Canada, contains many staging lakes, which are surrounded by annual cropland. Crop losses to waterfowl occur every year, but the severity fluctuates greatly from year to year. We obtained historical crop compensation data, waterfowl-staging surveys, harvest chronology, and weather records from various agencies. Using GIS, we referenced all data types to potential claim-land parcels (0.65 km2 for the damage model and 5 km2 for the density model). We constructed empirical landscape level logistic regression models, weighting factors influencing the magnitude of crop loss and density of waterfowl damage claims. Crop type, yield, abundance of waterfowl, and distance to feed stations (where bulk grain is provided to keep waterfowl off the nearby fields) were important to both the magnitude and density of damage. Oats were more susceptible to waterfowl damage than field peas, barley, or spring wheat. The end date of combining crops had a major influence on the magnitude of claims but had little effect on their density of claims. Magnitude was large in years when harvest was protracted and coincident with waterfowl staging. Distance to staging lakes was important to the density model, indicating that areas in close proximity to staging lakes experience chronic losses over time. In high-magnitude years, waterfowl damaged the more productive fields farther from staging lakes. Our results are consistent with the marginal value theorem and central place foraging: the relative benefits to foraging greater distances from a central place increases as resources are depleted near the central place.
Callaghan, Carolyn J.; Daneshfar, Bahram; and Thompson, Donald J.
"Modeling Waterfowl Damage to Crops Surrounding the Quill lakes in Saskatchewan,"
Human–Wildlife Interactions: Vol. 9
, Article 9.
Available at: http://digitalcommons.usu.edu/hwi/vol9/iss1/9