which way the other has gone. Smell serves as a means of identifying the other members of the same family. Outsiders are quickly detected and promptly driven away. The members of one family of squirrels which was closely watched were found to be very sociable, never quarreling among themselves. The parents were often seen sitting side by side feeding in perfect harmony (see fig. 29), while at other times this pair would sit together and rub noses in a very affectionate way. The only time that they were seen to show fight was when a strange male squirrel attempted to enter their burrow, and then the male of the pair promptly put the intruder to flight.
Fig. 29. Adult male and female Nelson Antelope Ground Squirrels, feeding in harmony side by side under wholly natural conditions. Photographed by J. Dixon, May 9, 1918, on lower San Emigdio Creek, Kern County. The openings under the horizontal layers of the wash banks afforded these squirrels safe retreats. Note the characteristic Ammospermophilus pose of body and tail.
The alarm note of the Nelson Antelope Ground Squirrel is much subdued as compared with the clear penetrating trill of the Desert Antelope Ground Squirrel. In fact, the former is much less frequently heard at all. While the junior author was watching a family of Nelson Squirrels at play on the morning of May 8, 1918, an old female was seen to disappear into one of the numerous holes in the bank. About two minutes later his attention was attracted by the low, inquisitive chirr of this same squirrel, which was standing motionless less than ten feet behind him. This alarm note was repeated five or six times at intervals of from 30 to 45 seconds. In uttering this note the mouth was opened, but the effort was not convulsive nor was the thorax greatly contracted. The note was subdued in tone and probably not audible to human ears at a distance exceeding one hundred feet. The confidential quality of the call note reminded the observer very much of the clucking note of the female valley quail when keeping her young together.
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