Birch mouse

Birch mice (genus Sicista) are small jumping rodents that resemble mice with long, tufted tails and very long hind legs, allowing for remarkable leaps. They are the only extant members of the family Sminthidae. They were formerly classified as part of the subfamily Sicistinae in the family Dipodidae alongside the jerboas and jumping mice. However, phylogenetic evidence supports all three of these belonging to distinct families, thus leaving only the jerboas in Dipodidae and promoting Sicistinae to its own family. They are native to Eurasian forests, shrublands, and grasslands, and have a vast geographic distribution. They dig shallow burrows in which they build nests from grass, and are typically active at night. They use their large feet to jump and climb on bushes and shrubs, using their toes and tails to cling to branches. Birch mice are omnivores and primarily eat seeds, berries, and insects. They hibernate during the winter, losing a great deal of weight in the process. They are all of a similar small size with relatively long tail lengths. Sicista contains several species, though population estimates are limited, the International Union for Conservation of Nature (IUCN) categorises multiple as endangered or critically endangered.