|Blue Jays chipped and ate the paint off
Deborah Jasak's house in Hopkinton, New Hampshire
Jays may be known as marauding rascals, raiding other birds
nests, monopolizing bird feeders, and otherwise creating mischief
in the yard. But Deborah Jasak never expected to find Blue Jays
chipping the paint off her freshly painted house. It started
around Christmas last year, just after the first snow. Every morning
I would wake up to the sound of Blue Jays pounding on my house,
said Deborah, a longtime FeederWatcher in Hopkinton, New Hampshire.
At first she thought the birds were cracking open seed shells or
trying to get insects from behind the paint. By carefully observing
the Blue Jays, she realized that they were actually flying to the
ground, retrieving the paint chips, and, to her amazement, eating
Because of the damage to her house (see photograph above) Deborah
wondered if shed have to stop feeding birds. But I
was not going to let these Blue Jays keep me from enjoying my
other birds, she said. So with the help of staff members
at seed stores, Audubon, and Project FeederWatch, she began experimenting
to see what might satisfy her flock of 40 Blue Jays better than
house paint. One by one, Deborah tried oyster shells, sand, dirt,
and trace minerals. The only solution that worked was eggshellsa
whole lot of eggshells! she said. 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 nibbling on
her house paint again.
After hearing of Deborahs difficulties, we wondered if
hers was an isolated case. Three more FeederWatchers from New
Hampshire, one from Pennsylvania, and one from Wisconsin reported
paint-eating jays. We also queried several Audubon chapters. Aside
from Massachusetts Audubon and the Audubon Society of New Hampshire,
none reported hearing about this Blue Jay behavior. But the stories
from these two states were quite compelling.
Becky Suomala, the naturalist at the Audubon Society of New Hampshire,
reported that every winter her office receives numerous inquiries
about Blue Jays eating paint. This past winter we had more
calls than the winter before, probably because the snow cover
lasted longer than usual. We had so many inquiries that we put
the topic on our Ask the Naturalist phone line and
on our web site.
Linda Cocca, a naturalist with Massachusetts Audubon, reported
that the groups Natural History Helpline receives a few
calls each winter about Blue Jays eating house paint. However,
in January 1996, Linda received more reports than usual, perhaps
because of the heavy snowfall (100 inches of snowfall in Massachusetts
that winter). She shared the information with a reporter from
the Boston Globe, which ran an article the next day. Linda
exclaimed, Pandoras box was opened! During the next
three days I received 160 reports, mainly from people in eastern
Massachusetts, who observed Blue Jays eating the light-colored
paint on their house or garage. Linda went on to say that
providing eggshells seemed to stop the behavior.
From our inquiries, a pattern started to emerge: Blue Jays in
the upper Northeast seemed to have a fondness for eating house
paint during winter and an even stronger affinity for eggshells.
This led us to many other questions.
How to Provide Eggshells
eggshells may contain harmful Salmonella bacteria.
Before providing eggshells, boil them for 10 minutes or
heat them in the oven for 20 minutes at 250° F. Let
the eggshells cool, then crush them into pieces smaller
than a dime. Offer the eggshells in a dish or on a low platform
Why paint? Can paint, like eggshells, serve as a source
of grit or calcium? Before Deborah provided eggshells, the Blue
Jays chose paint over the other sources of grit that she provided.
According to John Stauffer of the Paint
Quality Institute, paint manufacturers have used calcium carbonate,
or limestone, as an extender pigment in paint for hundreds of
years, making paint a source of calcium.
Why Blue Jays? Using data collected by citizen scientists
through the Labs Birds and Calcium Project, André
Dhondt and Wesley Hochachka found that Blue Jays consumed more
than twice as much calcium as other bird species. Furthermore,
as will be reported in The Condor this fall, they found
that Blue Jays, unlike other birds, continued to consume calcium
throughout the summer and into fall. Research has shown that songbirds
need calcium during the breeding season for egg laying and nestling
growth but dont store calcium in their bodies for use in
egg formation. Dhondt and Hochachka suggested that Blue Jays might
cache calcium in the fall for later use. However, Dhondt has since
raised the possibility that Blue Jays have a unique and as yet
unexplained need for calcium.
Why the Northeast? Could paint chipping be a foraging
skill passed down from one generation of Blue Jays to the next?
Or could the behavior be related to the lack of calcium in northeastern
soils? Compared to other regions, northeastern soils are naturally
poor in calcium. This deficiency is further exacerbated by the
relatively high amount of acid rain there (hydrogen ions in acid
rain leach calcium from the soil).
What to do. Providing eggshells clearly deters Blue Jays
from eating house paint. Deborahs flock of Blue Jays was
so large that it took two to three cups of eggshells per day to
satisfy it. She eventually enlisted the aid of a local baker who
saved eggshells for her. Its a long way to go for
the birds, Deborah said, but it was worth it.
Fortunately, most of Deborahs Blue Jay flock dispersed
with the arrival of spring. The few that remain no longer consume
many of the eggshells she puts out, and they are leaving her house
For more on the Birds and Calcium Project, see the Spring
1997, Winter 1998, and Spring 1999 issues of Birdscope.