Biology Reference
In-Depth Information
can ferment and make them sick, have a better sense of smell than Tree Swallows, which
probably can't take in the odors of flying insects as they snap and swallow them in flight.
Kiwis (flightless birds from New Zealand) are the only birds with nostrils close to the
tip oftheir bills. Their olfactory centers are about 10times the size ofthose ofother birds
relative to their size, and they apparently find the earthworms they feed on by smell.
Some homing pigeons use their sense of smell as one cue for navigating home. And
some seabirds use their sense of smell to locate their nest.
Great Horned Owls eat skunks. Their sense of smell hasn't been evaluated carefully, but
if they are good at smelling, apparently their sensibilities about what smells good are
quite different from ours!
Q Do vultures find dead animals by smell or by tracking predators or other scaven-
gers on the ground?
A
Researchers proved fairly long ago that Turkey Vultures can smell. In 1938, the Union
OilCompanydiscoveredthatbyinjectingastrong-smellingorganicchemicalcalledmer-
captan into gas lines, they could readily find leaks by monitoring vulture activity above
the pipelines. Some mercaptans smell like rotting cabbage or eggs. They and related
chemicals are released as carcasses decompose. To us, mercaptans smell horrible, but for
vultures they are associated with fine dining.
In a 1986 study in Panama, Turkey Vultures found 71 of 74 chicken carcasses within
three days. There was no time difference between finding concealed and unconcealed
carcasses, and the only carcasses the vultures seemingly had trouble finding were the
