Dear Tom,
I have seen Canada geese here in the Chicago area in the middle of winter. I thought they should have left for warmer climates. What is going on?

Jimmy Milson, Waukegan

Dear Jimmy,
Canada geese are tough and adaptable birds and, as long as food and open water are available, they can tolerate Chicago’s low winter temperatures. Canada geese in urban areas like metropolitan Chicago are drawn to grassy places like parks and expansive lawns because such places give them an unobstructed view of approaching predators. And Canada geese eat grass.

Anne Hobbs of the Cornell Lab of Ornithology says “Birds are mighty smart about taking care of themselves because that is what they are programmed to do: Take care of themselves.”

Canada geese can be separated into two categories: Those that migrate and those that do not. Data are incomplete, but non-migratory Canada geese seem to have appeared in the 1960s, and their numbers have been increasing dramatically ever since then.