Biology Reference
In-Depth Information
rid of the insects, then completely repair the holes with wood putty, in order to solve that
problem.
Q For the last three winters, Blue Jays have been pecking at the south-facing front of
our house, removing most of the paint by the end of the winter. Why do they do this,
and is there any way we can get them to stop? They're not only destructive, but it's
very annoying to have them hammering on the house every morning at daybreak!
A
During the winter of 2000-2001, Deborah Jasak, a Project FeederWatch participant,
called the Cornell Lab of Ornithology to report the same problem with Blue Jays taking
paint chips from her New Hampshire house. When FeederWatch staff asked others if
they'd hadthe same problem, they were surprised tohear just howwidespread it is. After
the
Boston Globe
ran a story about the issue, Massachusetts Audubon received 160 re-
ports of Blue Jays chipping and eating paint from houses.
Whydotheydoit?Paintmanufacturersusecalciumcarbonate,orlimestone,asanex-
tenderpigmentinpaint,makingpaintasourceofcalcium.AnotherFeederWatchresearch
project found that Blue Jays consumed more than twice as much calcium as other birds
do. And they seem to take paint from houses mostly in the Northeast, where soils are un-
usually low in calcium. When Deborah Jasak put out eggshells, the jays started taking
those instead and left her house alone. She tried other sources of calcium, such as oyster
shells, sand, dirt, and trace minerals, but eggshells were the only effective deterrent, and
if they got buried under snow, the jays returned to peeling paint off the house.
In rare cases, jays may take the eggshells yet continue to peel house paint. These in-
telligent, social birds develop habits that can be hard to break, and may simply enjoy the
