When white settlers first reached America, northern cardinals ranged across southeastern and south-central North America and along coastal areas of Mexico. Most of the Northeast and Great Lakes region were covered with virgin forest and the cardinal is not a forest bird. Rather, cardinals inhabit thickets, open woodlands and the border zone of fields and forest.
As the settlers cleared forest for timber, agriculture and residential areas, the cardinals spread northward; over two centuries, their range expanded through the eastern half of the U.S. and into southern Canada. They have also migrated westward, following the chain of towns and cities that are spaced along the primary rivers of the Plains States. Over the past decade, cardinals have begun to appear in eastern Colorado, primarily along the South Platte and Arkansas Valleys, and, in recent years, have been spotted on the outskirts of Metro Denver. In the southwestern U.S., irrigation and suburban sprawl have enticed them northward from Mexico and they are now found in southeastern California, southern Arizona and southwestern New Mexico.
This is one case where a native species has actually benefited from the activities of man. While we need to protect as much wilderness and natural habitat as possible, we can also benefit wildlife by making our "developed" areas eco-friendly.
