Factors determining the success of common loon (Gavia immer) nest platforms along the Aguasabon River, Ontario

Abstract

When the Ministry of Mines, Northern Development, Natural Resources, and Forestry in Nipigon, Ontario realized that loon nests in lakes surrounding the Aguasabon River were being flooded, they built and placed multiple nesting platforms in Hays Lake, Long Lake, and Aguasabon Lake. The six platforms on Long Lake were monitored annually utilizing two boat surveys, one in June, and one approximately two weeks later in July. Loon sightings were recorded using a handheld GPS unit. Using ArcGIS Pro, I analyzed the area surrounding each recorded waypoint to the Ontario Forest Resource Inventory data surrounding the lake. Land classification (MNRCODE) attribute in FRI, stand tree height, tree species, and area were considered. The analysis determined that loons most commonly nest when water level reaches a stable point within the month of May. Loons are most likely to be sighted in areas surrounded by productive forest dominated by black spruce, poplar, and balsam fir trees. The lack of success observed on the installed platforms is largely based on poor placement and anchoring. Additionally, it is suggested that platforms be placed in areas where loon chicks have not previously been sighted, as loons may be struggling to find suitable nesting habitat within their territory.