Biology Reference
In-Depth Information
Just as the basic food requirements for the two species are widely divergent, so too are their methods
of caching food and consuming it. Gray squirrels are justly noted for industriously storing nuts under-
ground. These are buried singly in dispersed fashion throughout each squirrel's territory.
This behavior has led to the common myth that gray squirrels remember where they've buried each
nut. Research has shown that grays don't have that kind of remarkable memory; although they may re-
call general areas where they've buried nuts, the location of individual nuts isn't part of their memory
bank.
That being the case, how do squirrels find the nuts when they need food? The answer lies in their
remarkable sense of smell. Gray squirrels locate buried nuts—even under many inches of snow—by
scent alone! This means that individual squirrels dig up nuts buried by other squirrels wherever they
happen to smell them. Such behavior, though it might seem a bit unjust, probably results in something
like a fair exchange in most cases.
This uncertain and somewhat haphazard retrieval of buried nuts has one vital, if unintended, result.
Many nuts are never found, and these sprout and grow into new nut trees. While some nuts, such as
the acorns of white oaks, will sprout on the surface of the ground, others must be buried in order to
germinate.
Red oak acorns germinate much better underground, and burial is almost a necessity for butternuts,
black walnuts, and hickories. Indeed, it's estimated that perhaps 95 percent of all hickory trees come
from nuts unwittingly planted by squirrels. Thus the relationship between the gray squirrel and nut trees
is really symbiotic: the squirrels require nuts in order to survive, and the nut trees require squirrels to
plant them. As an added complexity, researchers have learned that gray squirrels promptly consume
white oak acorns, which sprout soon after they fall, but bury red oak acorns, which need to spend the
winter underground in order to sprout effectively in the spring. Again, this arrangement benefits both
tree and squirrel. What a superb example of nature's intricate interrelationships!
Red squirrels also cache food, but in a far different manner. Their strategy is to fill storehouses—a
hollow tree or log, or an underground area— with as much food as they can pack away for the long
winter months. Particularly where the seeds of coniferous trees are their main food supply, these caches
can be enormous, sometimes numbering two or three thousand cones. These represent such a fine sup-
ply of seeds that the U.S. Forest Service sometimes appropriates them for use in starting conifer seed-
lings. This is not as harsh as it sounds, for the stolen cones are replaced with corn or other suitable food
to see the little hoarder through the winter.
One of the more amusing sights in nature is to watch a red squirrel transporting pine or fir cones to
its cache, or from cache to feeding site. Usually the squirrel grasps the cone by one end with its teeth,
so that the little creature looks for all the world as if it's puffing on a grotesquely large cigar!
No picture of squirrel food sources would be complete without mention of backyard feeders. The
popularity of feeders has exploded in the past few years, particularly in suburban areas, though a great
many rural residents have feeders, as well. The proliferation of rich supplies of sunflower seeds and
