Biology Reference
In-Depth Information
ligence—or even to define intelligence, for that matter. And if scientists can't even agree on a definition
of intelligence, it's virtually impossible for them to agree on a means of determining how much of it a
creature possesses.
Heinrich is a cautious scientist, understandably reluctant to place his head firmly on the scientific
chopping block by declaring that ravens are intelligent. However, he clearly leans in that direction when
he says that he believes they experience some level of consciousness that they use in making decisions:
“Whether that is 'intelligence' is subjective; but according to most people it is.” I certainly concur in
that judgment.
Crows are also widely regarded as intelligent, and perhaps they are, again depending on one's defin-
ition. However, one of the supposed measures of crow intelligence—the ability to count the number of
hunters in a group— is highly suspect. According to this oft-repeated tale, if crows see, for example,
four hunters go into a patch of woods, and then see only three depart, they know that the woods are
unsafe because a hunter remains there. Also according to the tale, above a given number the crows can
no longer tell whether or not all the hunters exit from the woods.
There might be a grain of truth in this: crows could conceivably recognize instinctively that two
hunters emerging from the woods don't look like as many as three or four. However, such incidents
are anecdotal, subject to a great deal of exaggeration, and, even if true, contain so many variables as
to make them totally speculative and unreliable. Beyond that, using such an incident as the basis for
saying that crows can count is straining credibility to the breaking point.
Crows are extremely social birds, and during the winter months they often gather in huge roosts that
may harbor close to a million members! In the daytime they travel as much as twenty miles from these
roosts in order to find food. Crows in large numbers can be a serious threat to crops, and need to be
controlled under some circumstances.
As many farmers and gardeners know to their sorrow, crows especially like sprouting corn seeds.
This has put the crow into marked disfavor with many, and has led to the use of various
devices—scarecrows and imitation great horned owls among them—in an attempt (usually unsuccess-
ful) to keep crows away during the critical period while the seeds are sprouting. However, on an over-
all basis, crows are regarded as beneficial because of the vast quantities of destructive insects, such as
grasshoppers and cutworms, that they consume.
Crows have no compunctions about eating whatever is available, and items such as insects and
sprouting corn form only a portion of their diet. Carrion, particularly in the form of roadkill, is a major
source of food for the crow, and it's a common sight to see these birds on a roadkill or waiting near it
until traffic permits them to resume feeding. Fruit, garbage, birds' eggs and nestlings, baby mice and
voles, and a variety of other small creatures are also important food sources for the crow.
Large numbers of crows have been killed in the past, and some still are, largely because of the dam-
age, real or assumed, that they cause. This seems to have had little effect on the crows, which have re-
mained abundant. Ravens are a different story, for they've been seriously persecuted at times, not only
with guns but also with poison and traps.
