Blue Jays Eating House Paint Damage to Debra Jasek's house caused by Blue Jays. During the winter of 2000-01, FeederWatcher Deborah Jasak called to report Blue Jays chipping the paint off of her house in Hopkinton, New Hampshire (pictured left). She wrote, “Every morning I would wake up to the sound of Blue Jays pounding on my house.” She watched them chip her paint and then fly to the ground to retrieve the chips. After trying several things, she found “the only solution that worked was eggshells–a whole lot of eggshells!” Thanks to donations from local bakers, Deborah offered two to three cups of shells per day, and every time the shells became buried under fresh snow, the Blue Jays would start chipping the paint again. We asked other participants if they had similar experiences and heard reports from the northeastern U.S. and eastern Canada, including one report from Donald Anderson in Jaffrey, New Hampshire, who reported having jays chipping paint off his house for the previous 27 winters! Linda Cocca, a naturalist with Massachusetts Audubon told us about an article that appeared in the Boston Globe in March of 1994 on the topic. During the next three days, she received 160 reports, almost all about jays chipping light-colored paint. From our inquiries a pattern started to emerge: The behavior was primarily observed in the upper Northeast, the behavior usually occurred when snow covered the ground, and almost always the target was light-colored paint. An investigation into paint ingredients found that limestone, a source of calcium, is often a key ingredient in paint. Scientists theorized that Blue Jays are caching paint chips for the calcium, something they need for egg laying in the spring. They don’t believe that the jays are eating the paint but rather are gathering into their crops, flying off, and then stashing it for later. FeederWatch participants in 1997 helped Cornell Lab researchers study calcium consumption in birds, and 39% of the observers in that study reported Blue Jays taking supplemental calcium, a value that was more than double that of any other species. Researchers think the problem is worst in the northeast because that region has been hard hit by acid rain, which depletes the soil of naturally occurring calcium. Learn more about the Lab’s research on acid rain and its effects on breeding birds. Deborah Jasak and others found that offering eggshells, another good source of calcium, stopped the paint-chipping behavior. And eggshells have the added advantage of being a source of grit, something else birds need to digest food. If Blue Jays are chipping the paint on your house, consider offering them eggshells after sterilizing them by boiling or heating in a 250 oven for 20 minutes.