Degus have well-developed sight, smell, and hearing. They are highly vocal and use various calls to communicate with one another, including alarm calls, mating calls, and communication between parents and young. Vision is very important in avoidance of predators and in foraging. It has been shown that degus are able to see ultraviolet wavelengths, and that their urine reflects in the UV range when fresh. It has therefore been suggested that degus' urine scent marks are also visual cues. These scent marks are also used as dust wallows, allowing members of a social group to identify each other by scent.
Communication Channels: visual ; tactile ; acoustic ; chemical
Other Communication Modes: scent marks
Perception Channels: visual ; tactile ; acoustic ; chemical
Octodon degus is considered the most common mammal in its range, and is not considered threatened or endangered.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
Degus are significant agricultural pests in some areas. They take advantage of cultivated prickly pear cactus, wheat, vineyards, and orchards as abundant food sources, and can do considerable damage. They are also known to host three species of parasites that can infect humans.
Negative Impacts: injures humans (carries human disease); crop pest
Degus are frequently kept as pets, and are used extensively in laboratory research. Because they are largely diurnal, they are useful in research on circadian rhythms, and their intolerance of sugars makes them ideal models for diabetes research.
Positive Impacts: pet trade ; research and education
Octodon degus affects the plant community in its habitat by selective browsing. Degus behaviorally reduce the fiber content of their diet, preferrentially eating shrubs such as Adesmia bedwellii, Baccharis paniculata, and Chenopodium petioare, which are less fibrous and less thorny than others. These species have been shown to increase their foliage area upon exclusion of degus. As degus are very common, they are themselves an important food source for their predators.
Degus often live in association with Bennett's chinchilla rats (Abrocoma bennettii). The two species are known to share burrow systems and have even been observed in the same chamber within a burrow. This is believed to be a mutualistic relationship, but it is not well understood.
Ecosystem Impact: creates habitat
Mutualist Species:
Degus are generalist herbivores. They feed on the leaves, bark, and seeds of shrubs and forbs. Among their favorite foods are the bark of Cestrum palqui and Mimosa cavenia, leaves and bark of Proustia cuneifolia, Atriplex repunda, and Acacia caven, annuals such as Erodium cicutarum when in season, green grasses, and thistle seeds. Degus choose food items that reduce fiber and increase nitrogen and moisture in the diet, and thus prefer young leaves and avoid woodier shrubs. Degus rely on microbial fermentation in their enlarged cecum (they are "hindgut fermenters") to digest their food. They reingest a large percentage of their feces, usually during the night. This allows them to maximize their digestion. Degus store food in the winter, and it has been reported that they occasionally eat meat in old age.
Plant Foods: leaves; wood, bark, or stems; seeds, grains, and nuts
Other Foods: dung
Foraging Behavior: stores or caches food
Primary Diet: herbivore (Folivore , Granivore , Lignivore); coprophage
Octodon degus is generally considered endemic to west central Chile, where it inhabits the lower slopes of the Andes. Although some have argued that its range may extend north into Peru, this is not well supported. It is common in the international pet trade, however, and is often used in laboratory studies outside of its native range.
Biogeographic Regions: neotropical (Native )
Octodon degus inhabits a mediterranean-type semi-arid shrubland ecosystem called "matorral", which is found on the western slopes of the Andes between 28 and 35 degrees south latitude. Further north the climate becomes too arid to support this plant community, and further south it is too wet. Degus appear to be limited to elevations below 1200 meters, both by the distribution of their habitat and by their intolerance of low oxygen partial pressure. Degus are well able to inhabit lands influenced by cattle grazing, and are agricultural pests in some areas.
Range elevation: 0 to 1200 m.
Habitat Regions: temperate ; terrestrial
Terrestrial Biomes: chaparral
Other Habitat Features: agricultural
In laboratory conditions, degus typically live five to eight years.
Typical lifespan
Status: captivity: 5 to 8 years.
Octodon degus superficially resembles a gerbil, but is much larger. Degus typically weigh between 170 and 300 g, and measure between 325 and 440 mm in length, including the tail. The fur is yellow-brown on the back and head, and the underparts and feet are cream colored. There is a pale band around the eye and, in some individuals, the neck. The tail is moderately long and conspicuously tufted. The ears are large and darkly pigmented. The fifth digit is reduced, and on the forefeet it has a nail instead of a claw. The cheekteeth are hypsodont and their biting surfaces resemble a figure of eight. Sexes are difficult to distinguish, but males tend to be about 10% larger than females. Pups are born furred and able to see, and begin exploring within hours of birth. Octodon degus can be distinguished from the two other members of the genus Octodon by slight differences in dental morphology. It is also smaller than its relatives and its tail is said to be more noticeably tufted.
Range mass: 170 to 300 g.
Range length: 325 to 440 mm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger
Average basal metabolic rate: 0.958 W.
Octodon degus is subject to predation by larger mammals such as culpeo foxes (Lycalopex culpaeus), and from the air by raptors such as barn owls (Tyto alba), short-eared owls (Asio flammeus), and black-chested buzzard eagles (Geranoaetus melanoleucus). Degus use vigilance and cover to avoid predators. Their pelage is also counter-shaded and matches the soil color, which reduces visibility to predators. Degus live socially and use alarm calls to warn others of danger. When a predator is spotted, they take cover in shrubby areas and may retreat to the communal burrow.
Known Predators:
Anti-predator Adaptations: cryptic
During the annual breeding season, male-male aggression temporarily increases. Males exclude other males from their burrow and monopolize the females (usually 2 to 4) who live there. Dustbathing and urine marking may be used in the defense of territory by both sexes, but these behaviors particularly increase in the male during the breeding season. Courting males often engage in mutual grooming with females, and frequently perform a courtship ritual which involves wagging of the tail and trembling of the body. The male then raises a hind leg and sprays urine onto the female. This may serve to familiarize her with his scent and perhaps make her more receptive to his advances in the future. Receptive females may sometimes enurinate males in a similar fashion. Related female degus may nurse each other's young.
Mating System: polygynous ; cooperative breeder
In the wild degus tend to breed once per year. The breeding season usually begins in late May (autumn in Chile), and the young are conceived in late winter to early spring (September to October). In wet years, degus may produce second litters. It has been suggested that degus may be induced ovulators, but this has not been established for certain. There is also some evidence that male reproductive organs may be sensitive to changes in photoperiod. The gestation period is 90 days, and litter size is typically 4-6 pups. The young are precocial. They are born with fur and teeth; their eyes are open and they are able to move about the nest on their own. Pups are weaned at 4 to 5 weeks, and become sexually mature between 12 and 16 weeks of age. Degus do not reach adult size until about 6 months of age, however, and they generally live in same-sex social groups until they are about 9 months old and their first breeding season occurs. It has been reported that pups raised in isolation in the laboratory experience severe neural and behavioral abnormalities.
Breeding interval: Degus breed once a year.
Breeding season: Wild degus breed in September and October.
Range number of offspring: 4 to 6.
Range gestation period: 90 to 95 days.
Range weaning age: 4 to 6 weeks.
Range time to independence: 4 to 6 weeks.
Range age at sexual or reproductive maturity (female): 12 to 16 weeks.
Range age at sexual or reproductive maturity (male): 16 (high) weeks.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous ; post-partum estrous
Average birth mass: 14 g.
Average number of offspring: 6.
Before conception can occur, the male degu must invest considerable energy in the defense of his territory and harem from other males. The female subsequently expends considerable energy in gestation and lactation. The pregnancy is relatively long for a rodent, and the young are born well developed. After birth, both parents protect and provision the pups. Degus nest communally, and groups of related females nurse one another's young. In the laboratory, the female remains close to the pups until two weeks after birth, and males have been observed to huddle with the young during this period without instances of infanticide. In the wild, male degus may spend as much time feeding and huddling with the young as females do. Pups begin to eat solid food at about two weeks of age, and venture out of the burrow at three weeks. Upon weaning at four to six weeks, the pups are able to live independently of the parents and form same-sex social groups until their first breeding season.
Parental Investment: precocial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Male, Female); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male, Female); pre-independence (Protecting: Male, Female)
The common degu (Octodon degus; /ˈdeɪɡuː/), or, historically, the degu, is a small hystricomorpha rodent endemic to the Chilean matorral ecoregion of central Chile.[2] The name degu on its own indicates either the entire genus Octodon or, more commonly, just the common degu. Common degus belong to the parvorder Caviomorpha of the infraorder Hystricognathi, along with the chinchilla and guinea pig. The word degu comes from the indigenous language of Chile, Mapudungun, and the word dewü, meaning 'mouse' or 'rat'.[3]
The animal may be kept as a domestic pet, though there are prohibitions on their ownership in some territories. As a pet, the animal is larger than a golden hamster but smaller than a fancy rat.
The common degu is a small animal with a body length of 25.0 to 31.0 cm (9.8–12.2 in) and a weight of 170 to 400 g (6.0 to 14.1 oz). It has yellow-brown fur above and creamy-yellow below, with yellow around the eyes and a paler band around the neck. It has a long, thin tail with a tufted, black tip, dark sparsely furred ears, and pale grey toes. Its fifth toe is small with a nail, rather than a claw, on the fore feet. Its hind feet are bristled. Its cheek teeth are shaped like figures-of-eight, hence the degu's genus name Octodon.[4]
Common degus are highly social. They live in burrows, and, by digging communally, they are able to construct larger and more elaborate burrows than they could on their own.[5] Degus digging together coordinate their activities, forming digging chains.[6] Females living in the same group have been shown to spontaneously nest communally;[7][8] they nurse one another's young. They spend a large amount of time on the surface, where they forage for food.[6] When foraging, their ability to detect predators is increased in larger groups,[9] and each animal needs to spend less time in vigilance.
Common degus exhibit a wide array of communication techniques. They have an elaborate vocal repertoire comprising up to 15 different sounds,[10] and the young need to be able to hear their mother's calls if the emotional systems in their brains are to develop properly.[11] They use their urine to scent mark,[12] and experiments have shown that they react to one another's marks,[13] although in males the hormone testosterone may suppress their sense of smell somewhat.[14]
Common degus are seasonal breeders; the breeding season for wild degus begins in the Chilean autumn when day and night are roughly equal,[15] with pups born in early to mid-spring.[16] Female degus are pregnant for approximately ninety days,[4][17] having a comparatively long gestation period compared to other non-caviomorph rodents. Female pregnant weight varies over the course of gestation and according to litter size;[18] litters contain an average of six pups,[7] but size can range from one or two up to twelve young.[18] Common degu pups are born relatively precocial, fully furred and with eyes open, and their auditory and visual systems are functional at birth.[19] Unlike most other rodents, male common degus also take part in protecting and raising their pups until they are old enough to leave the family.[20]
Unlike some other octodontids, common degus are diurnal[21] (active during the day), and they have good vision. Their retinas include rod cells and two types of cone cells, corresponding to peak sensitivity in the green and ultraviolet regions of the spectrum.[22] Behavioral experiments have shown that degus are able to discriminate ultraviolet light from the wavelengths visible to humans; it is likely that this ultraviolet sensitivity has a social function, since both their ventral (stomach) fur and their urine are highly UV reflective.[23]
Common degus are strictly herbivorous, in the wild feeding on grasses and browsing the leaves of shrubs, though they will also take seeds.[24] Throughout much of the year forage is dried[21] and so common degus are specially adapted to a very high fibre intake,[25] and this varies between food types and environmental conditions.[26] Like some other herbivores such as rabbits, they perform coprophagy (faecal reingestion) so as to extract more nutrition from their diet.[27] This also serves to maintain healthy gut function during times when food is scarce.[27] Although they are active by day, in high summer they do not leave their burrows in the middle of the day[21] and instead emerge to forage in the mornings and evenings.
Perhaps the most remarkable feature of common degu physiology is their intolerance of dietary sugar. Common degus have been found to have a divergent insulin structure (one of the hormones that regulate blood glucose level) and so are highly susceptible to developing diabetes mellitus when fed regularly on a diet containing free sugars.[28] This is thought to be due to evolutionary pressure arising from the lack of availability of free sugars in the degu's natural environment.[29] Because of this, the ingredients of non-degu-specific hard feed formulations given to captive common degus should be checked for sugar-laden ingredients, such as molasses, honey, and glucose syrup.
Common degus entered the research spotlight due to their unique relationship with sugar and diabetes, but are also studied for a wide variety of other reasons. Neuroscientists at the Riken Institute in Tokyo, Japan, used common degus for research into tool use in animals with good eye-and-paw coordination, in which they spontaneously learned to use a tiny rake to retrieve out-of-reach seeds.[30] Common degus have also been found to spontaneously stack objects in order of decreasing size.[31] In both cases it is the first time these behaviours have been recorded in animals other than apes and birds.
Another interesting area of common degu research is circadian rhythm function, i.e. the ability of the brain to tell what time of day it is. Degus have the ability to show both diurnal and nocturnal rhythms if the environment permits,[32] allowing a unique opportunity for study. Common degus can take cues that do not relate to day length, such as temperature,[33] melatonin levels[34] and even scents from other degus[35] to adjust their rhythms.
Common degus are also invaluable in development and aging studies. Research has shown that separation anxiety caused by separating pups from their mother from an early age for periods of half an hour or more can cause developmental and behavioural changes in later life, similar to ADHD in humans.[36] In elderly common degus, neural markers have been discovered which are remarkably similar to those in humans with Alzheimer's disease, which is the first time this has been seen in a wild-type rodent.[37]
After initial interest into common degus as research subjects, they have become popular as pets, though until recently they were seldom found in pet shops. Their advantages over traditional small pets are their diurnal habits, bubbly personalities, the haired tail (as compared to rats and mice) and their lifespan: they are reported to live up to 13 years under ideal circumstances (though a poor gene pool or genetic background often reduces a pet degu's lifespan significantly). The average lifespan of a common degu in captivity is typically around six to eight years of age.
One disadvantage of the common degu as a pet is their predisposition to chewing, due to their continually growing incisor and molar teeth.[4] For this reason, common degus cannot be housed in plastic-bottomed cages typically found in pet stores. A metal cage with multiple levels made for rats and secured double latches works best. It is important to line the levels with grass mats or a soft fabric so that the common degus do not get bumblefoot.
Untamed common degus, as with some other small animals kept as pets, can be prone to biting, but their intelligence makes them easy to tame. Regular non-predatory handling and food offerings help with this transition. It is important to never try to catch a common degu by the tail because the skin and tuft at the end is easily "shed" (pulled off). This helps common degus in the wild elude capture by predators, but it is painful to the creature and the tail end will not grow back. When tail shedding occurs, common degus will chew off the damaged portion. This can reduce the chances of infection.
Common degus often "groom" their human owners with a gentle nibbling action, and readily bond with any person spending time with them. Common degus need regular sand baths, like Chinchillas need dust baths, to keep their coats healthy and free from grease. Chinchilla sand is ideal for this. They should have access to these baths regularly, preferably two or three times a week for half an hour at a time. However, too frequently, daily sand bathing can make their coats soiled.
Some jurisdictions consider common degus as a potential invasive species and forbid owning them as a pet.
In the United States, they are illegal to own in California,[38] Utah,[39] Georgia, Connecticut,[40] and Alaska.[41]
Common degus in captivity
Two common degus outside
Baby common degus nursing
Adult common degu perched on a platform
Two common degus
Common degu scratching
Three common degu pups, eight days old
Two young common degus
Common degu performing a trick
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Newborn common degu (1 day old)
Mother nursing newborn pups
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Curious adults in a wooden cage
Degu with blue coat, a common colour variation
The common degu (Octodon degus; /ˈdeɪɡuː/), or, historically, the degu, is a small hystricomorpha rodent endemic to the Chilean matorral ecoregion of central Chile. The name degu on its own indicates either the entire genus Octodon or, more commonly, just the common degu. Common degus belong to the parvorder Caviomorpha of the infraorder Hystricognathi, along with the chinchilla and guinea pig. The word degu comes from the indigenous language of Chile, Mapudungun, and the word dewü, meaning 'mouse' or 'rat'.
The animal may be kept as a domestic pet, though there are prohibitions on their ownership in some territories. As a pet, the animal is larger than a golden hamster but smaller than a fancy rat.
_Degu.JPG)
