Degu is a small rodent with greyish brown coat, which is lighter on the under part. The tail exhibits a black, bushy tip. The closest relatives of this highly social and curious animal are the guinea pig and chinchilla. Males and females look alike, although females are around 10% smaller than males. Newborn babies of this species are able to see and start exploring the environment during the first few hours of their lives. In addition, degus are very vocal animals. They usually live 3 - 4 years in the wild and 5 - 8 years in captivity.
Degus mainly occur in the west central Chile, where they live in "matorral" habitat - a mediterranean-type semi-arid shrubland, located on the lower western slopes of the Andes. These rodents can often be seen in areas, dominated by cattle grazing, due to which they are considered a pest species in certain parts of their range.
Degus are social animals, forming small groups of 1 - 2 males and 2 - 5 females, which are typically related. Females of a group practice allomothering, rearing offspring of one another. Each group has its own territory, where it lives during most of the year. These diurnal animals are active in the morning and evening. Degus are semi-fossorial, digging huge burrow systems, where they live together with Bennett's chinchilla rats. Feeding occurs above the surface, although they tend to descend to the low branches of shrubs to find food. Degus enjoy wallowing in dust. Each group has its favorite wallowing sites, which they mark with their gland secretions. Due to these secretions, group members are able to identify each other and establish their territory.
Degus have a polygynous mating system. During the breeding season, males aggressively defend their mating rights. They usually drive out other males from their burrow, limiting their access to 2 - 4 females, living there. Populations in the wild are known to breed once a year, typically during the autumn, in late May. Young are born between late winter and early spring (in September-October). Gestation period lasts for 90 days, yielding a litter of 4 - 6 babies. The number of litters per year depends on weather conditions: usually, wet years bring 2 litter, while dry years yield only a single litter. Newborn degus are precocial, possessing fur and teeth. They are born with open eyes and can move around the nest independently. Weaning occurs within 4 - 5 weeks, while sexual maturity is reached at 12 - 16 weeks old. They attain adult size at 6 months old. As a general rule, young degus remain in single-sex groups until around 9 months of age, and only after that they begin breeding.
Currently, there are no notable threats to the overall population of these rodents.
According to IUCN, the Degus is abundant and widespread throughout its range but no overall population estimate is available. Currently, this species is classified as Least Concern (LC) on the IUCN Red List.
Due to selective browsing, degus play an important role in the ecosystem of their range. They are known to reduce the fiber content of their diet by consuming shrubs that are relatively less fibrous and thorny. They often drive away conspecifics in order to increase their feeding area. On the other hand, due to consuming and damaging cultivated prickly pear cactus, wheat, vineyards and orchards, degus are considered a pest species in some part of their range. In other parts of their range, these animals are a key prey species for local predators.