THE GOLDEN MANTLED
GROUND SQUIRREL
by Ralph R. Huestis

Special Number - 1951

BEHAVIOR

The inherent or unconditioned behavior of these squirrels is interesting and can be usefully compared with the learned or conditioned responses that are in time built up by contact of squirrels with the park visitors. Young squirrels are quite timid upon emergence and for a few days depend upon the early morning hours for their initial foraging, a time when few people are around. They stay near a burrow entrance and hole up promptly if disturbed. This timidity is typical of the behavior of all squirrels in regions where contact with man is a rare incident. The air of easy assurance adopted by older park squirrels is evidence of their domesticability.

". . . tail above his back about the angle a stove lifter projects from the lid . . ."

These rodents have quite a tendency to dig in the ground and the young ones do a good deal of random digging before they actually tunnel a home site for themselves. In digging, the head is lowered and the fore limbs are moved very rapidly for a brief interval. The limbs are then held still while the head is raised for a look around. Digging and looking alternate at rapid intervals. If partly within a burrow a squirrel will back out to raise his head for observation. When well into a burrow, a squirrel, observed at the rim on July 15 1938, continued digging without kicking out the loose dirt which soon covered him. Hidden by this the squirrel continued on into the ground. About ten minutes later he burst out head first. The maneuver simultaneously cleared the burrow entrance and prepared it for possible retreat and got the squirrel clear of the entrance without embarrassing him with the adherence of loose earth. The interval had presumably been used to dig a length of burrow and a turn around.

Interesting comparisons can be made between the golden-mantled ground squirrel and a rather small brown gopher which occupies the same territory and is therefore a competitor. Both mammals dig a tunnel system, that of the gopher being attended to particularly during the winter so that "he, while his companion sleeps, is toiling upward in the night." The squirrel feeds for the most part above ground while the gopher feeds for the most part underground on roots, there available, or on greens and grains pulled through the roof of the tunnel or gathered in short surreptitious forays launched from a tunnel entrance. In the latter the gopher emerges headfirst but goes to earth tail first. This reversal of direction without turning the body cannot be profitably employed by the squirrel for he ranges for a distance and maneuvers his body without regard to the position of the tunnel entrance. The squirrel always goes to earth head first. However, if a squirrel partly emerged is alarmed, he backs down gopher-like into the tunnel.

". . . hungry little squirrels were adopted and fed by rim campground visitors."

"The air of easy assurance."

Squirrels can occasionally be seen carrying dry material which they presumably use for bedding. Grass from the previous fall which has been pressed down by the snow, dries rapidly when the snow has melted and so provides an acceptable bedding material. An individual squirrel, when not interfered with during the process, may make trip after trip to the same site of supply and carry a load of dry grass back to a tunnel each time. The route taken for the journey out may be repeated each time but a different route is usually chosen for the return journey and this is repeated on each return. An exception to this was provided by a squirrel in the utilities area which made twelve trips in carrying old bedding from one tunnel which it deposited in another. In this moving process the squirrel took the shortest route between the two tunnel entrances, which were only about thirty feet apart, and the routes going and coming were therefore coincident.

A squirrel gathering bedding works vigorously with forepaws and teeth to loosen grass which is taken between the jaws. The squirrel then stands up and trims this load into a neat bundle. More grass may be added and the trimming process repeated. Thus to arrange the load between the jaws a squirrel makes rapid and complicated movements with the forepaws. As a result he can run with his grass sheaf without stepping on loose ends and as the bundle does not project laterally much further than the ears the squirrel can enter a tunnel entrance on the run without embarrassment. A squirrel running with bedding has been seen to stop, stand up and retrim his load when a loose end of dried grass became detached and started to drag. On one occasion a squirrel running down the inner wall of the Sinnott Memorial ramp, stopped at the lower turn where two visitors offered him peanuts. To accept these the squirrel was obliged to put down his sheaf of grass and by running down the ramp the writer was able to prevent the squirrel from retrieving the grass before he ran away. This grass sheaf was in the form of an 8 which the squirrel had been holding in the center so a loop projected on each side. The grass in this bundle held together and could be lifted by the center or either loop without becoming disentangled.

Like most rodents the golden-mantled ground squirrel grooms himself around the head, neck, and belly with his fore paws. Hinder parts except the tail, are worked over with the teeth. The tail is combed by a sort of shucking motion with the fore paws and combed with the teeth as well. Grooming is particularly important in small mammals since a smooth coat conserves heat which radiates rapidly from the relatively large surface of a small creature. Squirrels dust themselves by a moderate rolling in dust piles often raised by a few rapid paw strokes for the purpose. They frequently save time by diving into dust like a base-runner making a head-first second. Frequently after the dive they lie spread-eagled in the dust for a brief period and this same position, with all limbs extended, may be used in resting. A well nourished little squirrel thus stretched out, after an interval of peanut gathering, has all the air of smugness carried by a lucky investor after a hard hour of coupon clipping.

". . . edible objects are always lifted first by the jaws and then transferred to the forepaws . . ."

Squirrels forage busily and nose over the ground for food. They frequently forage by standing on the hind limbs while they reach out and pull vegetation to the mouth with the fore paws. In this manner they nibble young leaves and flower buds of Newberry's knotweed and bleeding-heart and the seeds of wild grasses, the heads of which they obtain by arm over arm reeling in of the stem. It is interesting that in spite of this use of the fore limbs in a special circumstance, that edible objects like peanuts are always lifted first by the jaws and then transferred to the fore paws for manipulation during husking or fragmentation prior to storage in the cheek pouches. Occasionally a squirrel with its mouth full of food will clutch an object on the ground and pull it toward the body but will then merely hold it with its paw until the mouth can be used as the grasping organ.

The golden-mantled ground squirrel has a vocabulary of at least four different sounds. There is a high- pitched "peesk" which is quite bird-like in tone, sometimes followed by a trill which is rather more musical than the similar trill of the western chipping sparrow. Both single and multiple noses seem prompted by excitement or alarm. These sounds are made while sitting, sometimes with one foot raised. The mouth is widely opened for the first sound and the body vibrates obviously with the trill. On August 6, 1938, the writer stopped to investigate a singing squirrel which had gathered an audience of a number of campers. One of them estimated that the squirrel, presumably a female since it was occasionally followed by young, had already sung for an hour and "sang almost every day!" There is a throaty little growl which is uttered as a warning to interlopers and during pursuit of them or while in the throes of combat. This sound is commonly employed when squirrels are competing for peanuts. Rather rarely a squirrel running from a pursuer, utters a series of high squealing notes when pursuit is close. In general these animals are rather silent and are usually credited with the single note first mentioned (Bailey, 193, p. 140).