Biology Reference
In-Depth Information
haviors, and detailed research into the question hasn't been done. So although my guess
is yes, we can't be scientifically certain.
CROWS NEVER FORGET EITHER
We know that American Crows
remember human faces, thanks to a fascinating 2008
study. John M. Marzluff, a wildlife biologist at the University of Washington, noticed
that birds he'd previously trapped seemed more wary of him and were harder to catch
than crows that hadn'tbeen trapped byhim before. Sohedevised anexperiment tosee if
the crows really could recognize his face.
To test whether the birds recognized faces separately from clothing, gait, and other
characteristics,Dr.MarzluffgotsomerubbercavemanandDickCheneymasks.Wearing
the caveman mask, he and his team trapped and banded seven crows on the university's
campus in Seattle. In the months that followed, Dr. Marzluff and his students and volun-
teers walked prescribed routes around campus not bothering crows, but wearing either
the caveman or the Dick Cheney mask. The crows scolded people in the “dangerous”
caveman mask significantly more than they did before they were trapped, even when the
mask was disguised with a hat or worn upside down. The Cheney mask provoked little
reaction.
Over the following two years, even though no more crows were trapped or banded by
people wearing the caveman mask, the effect actually multiplied. Wearing the caveman
mask on one walk through campus, Dr. Marzluff was scolded by 47 of the 53 crows he
encountered, many more than had experienced or witnessed the initial trapping. He hy-
pothesizes that crows learn to recognize threatening humans from both experience and
from their parents and others in their flock.
ThenDr.Marzluffrepeated theexperiment usingmorerealistic masksmadebyapro-
fessionalmaskmaker,trappingcrowsatvariousspotsinSeattlewhilewearingonemask,
the “dangerous” one. Afterward, he enlisted volunteers to walk through various areas of
Seattle wearing either the dangerous mask or another style that the crows had not seen.
The reaction to people wearing the dangerous mask was significant — crows scolded
them, and in downtown Seattle even flew at them so close they almost touched them.
The crows unerringly scolded the people wearing the dangerous mask rather than people
wearing the mask that hadn't been worn during trapping.
YoungAmericanCrowstypicallydonotbreeduntiltheyarefouryearsorolder.Inmost
populationstheyounghelptheirparentsraisenewbroodsforafewyears.Families may
include up to 15 individuals and contain young from five different years.
