Unlike ducks housed under
red or white light, ducks housed in the blue pen showed
a higher level of anxiety; while evaluators were in the
pen a majority of them began panting, they were much
less inquisitive than other ducks, they took longer to exhibit
normal social behavior once evaluation was completed,
and they frequently “swarmed” when no people
were present. There were no differences in any measurements
between the red and white-lighted pens. These
data suggest that unlike the chicken, blue lights may be
inappropriate for raising Pekin ducks in a commercial
setting.