Lady Cardinal

Female Northern Cardinal at a Calibrated Feeder.

This device can be set to open the feed hopper to birds of a specific weight. Currently it is set for Cardinals who weigh the same as 6 nickels.

Heavier birds cause the perch to lower beyond the feeding hole.

Lighter birds cannot lower the perch enough to reveal the opening.

This feeder is the source of great frustration to House Finches. They can see the food but cannot peck through the clear plastic.