1997-06-13_REPORT - M1981302 (18)

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10. Behavior A- Individual 1. Locomotion a. Jumping- The saltatorW powers of Z. hudsonius are well described, and are believed to occur primarily when an animal is frightened. Quimby (1951) noted that the species may jump as far as three feet, while other authors claim to have observed jumps up to 10 feet (Krutzsch 1954), but these observations are in doubt (Quimby 1951). Quimby (1951) found the greatest jumps to occur initially and normally cover a distance of two to three feet; subsequent jumps were shorter but more rapid. A jumping mouse in full retreat progressed by jumps of about one foot. As a means of protection, the animal may move by several long bounds and then stop or remain motionless. When not frightened, animals may progress by a series of short hops of one to six inches (Whitaker 1972). It is believed the tail acts as a balancing organ during jumping (Krutzsch 1954). b. Walking/Crawling- Whitaker (1972) states that the common name of this species is a misnomer. Mice of the species do not normally progress by jumping, but more often move slowly through the grass, and frequently crawl through the grass or under the grass, sometimes flattening their bodies to the ground and proceeding on all fours. C. Swimming- Whitaker (1972) reported that several authors have found Z. hudsonius to be a good swimmer both on the surface and underwater. Quimby (1951) observed an individual swim rapidly by lunges produced by sweeping strokes of the hind limbs employed simultaneously, and swim more steadily and slowly by using all four limbs one at a time, with the anterior part of the body being held high in the water. The tail is not used for swimming, either for propulsion or as a rudder. d. Climbing- Z. hudsonius has been observed to climb over brush, and to climb up grass stems during feeding (Whitaker 1972). e. Digging- Quimby (1951) described how caged Z. hudsonius construct underground burrows: "After selecting a spot, usually a depression, the animal began to excavate the soil by means of the front feet, throwing it out behind. This process continued until the hole was deep enough to enclose the anterior half of the mouse, at which time the hind feet were also brought into action to throw the loose dirt out of the burrow." r. Washing- Zapus have been observed to wash their feet, faces, and especially their long tails; "The tail was grasped in the forepaws, and passed completely through the mouth, whereas the hands and feet were washed by means of the forepaws" (Whitaker 1972). 2. Voice and Noises- Quimby (1951) found that the young Z. hudsonius at birth are naked and helpless, but emit a high-pitched squeaking sound, audible for several feet. A "suckling note" is made during the first week. Adults are usually silent, but a few sounds have been recorded, such as FzW Amu Survey Pi scs,I= Much Ll. 1"3 1