Can the presence of Canada geese endanger the loon and fish population of a lake?
A quick history: Canada geese, originally native to southern Ontario, were virtually extirpated there as a nesting bird by the turn of the 20th century. In the 1960s, they were reintroduced. By that time, southern Ontario, with its parks, lawns, golf courses, and agricultural croplands – not to mention hunting restrictions and lack of natural predators– was an ideal habitat. The population exploded, and in some places the geese have become a well-known nuisance.
Geese have been making their way north into cottage country. But they haven’t changed their diets – they are vegetarians with a strong preference for short grasses in open areas – so the fish population is probably safe. And while geese (and what they leave behind) could become bothersome in the parts of cottage country being urbanized with lawns and golf courses, they shouldn’t cause problems on traditional lakes fringed by trees.
Whether Canada geese are simply migrating through or have set up housekeeping on a lake, it’s not likely that they’ll settle in large numbers and it’s unlikely a few pairs on a lake would make it difficult for loons to find nesting sites.