![]() Once they reach adulthood, they usually have their own burrow and search for food on their own. Grazing negatively impacts the Jerboa pre- and post-hibernation population, but not the survival rate. Also, more food availability during pre-hibernation contributes to larger jerboa body mass in ungrazed regions, and entices more jerboas to migrate to ungrazed areas during post-hibernation. Just like other animals that hibernate, these creatures are heavier pre-hibernation specifically in ungrazed sites (Shuai). Temporary burrows are shorter in length than permanent burrows. Jerboas hibernate during the winter and use the permanent winter burrow for this. The permanent summer burrow is actively used throughout the summer and the young are raised there. They also have two permanent burrows: one for summer and one for winter. They have a second, temporary burrow used for hunting at night. A temporary, summer day burrow is used for cover while hunting during the daylight. Related jerboas often create four types of burrows. This allows the jerboa to quickly escape predators. In most cases, burrows are constructed with an emergency exit that ends just below the surface or opens at the surface but is not strongly obstructed. In the summer, jerboas occupying holes plug the entrance to keep out hot air and, some researchers speculate, predators. During the rainy season, they make tunnels in mounds or hills to reduce the risk of flooding. They dig the entrances to their burrow near plant life, especially along field borders. At night, they leave the burrows due to the cooler temperature of their environment. During the heat of the day, they shelter in burrows. Jerboas are most active at twilight (crepuscular). This may explain why evolution of bipedal locomotion is favored in desert-dwelling rodents that forage in open habitats. The bipedal locomotion of jerboas involves hopping, skipping, and running gaits, associated with rapid and frequent, difficult-to-predict changes in speed and direction, facilitating predator evasion relative to quadrupedal locomotion. Some species of the jerboa family have long ears like a rabbit, whilst others have ears that are short like those of a mouse or rat. This colour usually matches the jerboa habitat (an example of cryptic colouration). Jerboa fur is fine, and usually the colour of sand. Jerboas use their tails to balance when hopping, and as a prop when sitting upright. ![]() The tail of a jerboa can be longer than its head and body, and a white cluster of hair is commonly seen at the end of the tail. Like other bipedal animals, their foramen magnum - the hole at the base of the skull - is forward-shifted, which enhances two-legged locomotion. Also unlike Kangaroos, primary tendons in the hindlimbs only recovered and reused about 3.1-14.3% of energy contributed to the jump, lower than many hopping animals. However, when examined closely, their locomotion differs: In addition to speed, they make use of sharp turns and great vertical leaps, to confuse and escape predators. Jerboas move around in a similar manner to kangaroos, which is by hopping, or saltation. Both have long hind legs, short forelegs, and long tails. Jerboas look somewhat like miniature kangaroos, and have some external similarities. ![]() ![]() However, phylogenetic analysis split all three as distinct families, leaving just the jerboas in Dipodidae and revealing them to be a monophyletic group. ![]() Jerboas, as previously defined, were thought to be paraphyletic, with the jumping mice ( Zapodidae) and birch mice ( Sminthidae) also classified in the family Dipodidae. ![]()
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