Black-billed magpies were around Calgary before people were. They originally coexisted with bison herds, feasting on the insects on their backs. As these herds were quite large, so was the population of magpies. As times changed and the herds diminished, it was the open prairies that attracted farmers and herds of cattle that the magpies could adapt to and feed off the insects that were attracted by this different co-inhabitant. They are very adept at finding food and surviving in both the harsh winters and scorching summers. This allowed them to maintain their foothold in the prairies and has likely kept them from needing to expand futher.
