Common degu

{{Hatnote|This species was historically called degu. See degu for a list of other degu species now considered distinct from the common degu.}}

{{Speciesbox

| image = Octodon degus -Heidelberg Zoo, Germany-8a.jpg

| image_caption = At Heidelberg Zoo, Germany

| status = LC

| status_system = IUCN3.1

| status_ref = {{cite iucn |author=Roach, N. |date=2016 |title=Octodon degus |volume=2016 |page=e.T15088A78321302 |doi=10.2305/IUCN.UK.2016-2.RLTS.T15088A78321302.en |access-date=19 November 2021}}

| genus = Octodon

| species = degus

| authority = (Molina, 1782)

| range_map = Octodon degus range.svg

| range_map_caption = Range of O. degus

| synonyms =

Sciurus degus Molina, 1782

Octodon degus: Waterhouse, 1848

}}

The common degu (Octodon degus; {{IPAc-en|ˈ|d|eɪ|ɡ|uː}}), or, historically, the degu, is a small hystricomorpha rodent endemic to the Chilean matorral ecoregion of central Chile.C. Michael Hogan & World Wildlife Fund. 2013. Chilean Matorral. Ed. Mark McGinley. Encyclopedia of Earth. National Council for Science and the Environment. Washington DC 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'.{{Citation |title=Diccionario Mapuche: Mapudungun/Español, Español/Mapudungun |language=es |edition=2nd |year=2006 |editor=Muñoz Urrutia, Rafael |location=Santiago, Chile |isbn=978-956-8287-99-3 |pages=104, 105, 141 |publisher=Editorial Centro Gráfico}}

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.

Description

The common degu is a small animal with a body length of {{convert|25.0|to(-)|31.0|cm|in|abbr=on}} and a weight of {{convert|170|to|400|g|oz|abbr=on}}. 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.

Social behavior

File:Octodon degus -Artis Zoo, Netherlands-8b.jpg in the Netherlands]]

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.{{Citation|last1=Ebensperger| first1=L. A.| last2=Bozinovic| first2=F.| year=2000| title=Communal burrowing in the hystricognath rodent, Octodon degus: A benefit of sociality?| journal=Behavioural and Ecological Sociobiology| volume=47| pages=365–369|issn=0340-5443|doi=10.1007/s002650050678|issue=5| hdl=10533/172245| s2cid=12859012| hdl-access=free}} Degus digging together coordinate their activities, forming digging chains.{{Citation| last1=Ebensperger| first1=L. A.| last2=Bozinovic| first2=F.| year=2000b| title=Energetics and burrowing behaviour in the semifossorial degu Octodon degus (Rodentia: Octodontidae)| journal=Journal of Zoology| volume=252| pages=179–186|doi=10.1111/j.1469-7998.2000.tb00613.x|issue=2| hdl=10533/172199| hdl-access=free}} Females living in the same group have been shown to spontaneously nest communally;{{Citation| last1=Ebensperger| first1=L.A.| last2=Veloso| first2=C.| last3=Wallem| first3=P.| year=2002| title=Do female degus communally nest and nurse their pups?| journal=Journal of Ethology| volume=20| pages=143–146|doi=10.1007/s10164-002-0063-x| issn=0289-0771| issue=2| s2cid=38854503}}{{Citation| last1=Ebensperger| first1=L.A.| last2=Hurtado| first2=M.| last3=Lacey| first3=E.| last4=Chang| first4=A.| year=2004| title=Communal nesting and kinship in degus (Octodon degus)| journal=Naturwissenschaften| volume=91| pages=391–395| doi=10.1007/s00114-004-0545-5| issn=0028-1042| pmid=15309311| last5=Chang| first5=AT| issue=8| bibcode=2004NW.....91..391E| hdl=10533/175502| s2cid=929721| hdl-access=free}} they nurse one another's young. They spend a large amount of time on the surface, where they forage for food. When foraging, their ability to detect predators is increased in larger groups,{{Citation| last1=Quirici| first1=V.| last2=Castro| first2=R.A.| last3=Oyarzun| first3=J.| last4=Ebensperger| first4=L.A.| year=2008| title=Female degus (Octodon degus) monitor their environment while foraging socially| journal=Anim Cogn| volume=11| pages=441–448| doi=10.1007/s10071-007-0134-z| issn=1435-9448| pmid=18214556| issue=3| s2cid=17723026}} 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,{{Citation| last=Long| first=C.V.| year= 2007| title= Vocalisations of the degu (Octodon degus), a social caviomorph rodent| journal= Bioacoustics| volume= 16| issue=3| pages= 223–244| issn=0952-4622| doi=10.1080/09524622.2007.9753579| s2cid=84569309}} and the young need to be able to hear their mother's calls if the emotional systems in their brains are to develop properly.{{Citation| last1=Ziabreva |first1=I. |last2=Schnabel |first2=R. |last3=Poeggel |first3=G. |last4=Braun |first4=K. | year=2003 |title=Mother's voice "buffers" separation-induced receptor changes in the prefrontal cortex of Octodon degus |journal=Neuroscience | volume=119 | pages=433–441| doi=10.1016/S0306-4522(03)00123-4| issue=2| pmid=12770557|s2cid=28635328 }} They use their urine to scent mark,{{Citation |last=Kleiman |first=D.G. |title=The Biology of Hystricomorph Rodents |year=1974 |editor-last=Rowlands |editor-first=I. W. |editor-last2=Weir |editor-first2=B. J. |chapter=Patterns of behaviour in hystricomorph rodents |place=London |publisher=Academic Press |lccn=74005683}} and experiments have shown that they react to one another's marks,{{Citation| last1=Fischer| first1=R.| last2=Meunier| first2=G.| year=1985| title=Responses to conspecifics' urine by the degu Octodon degus| journal=Physiological Behaviour| volume=34| pages=999–1001| doi=10.1016/0031-9384(85)90027-7| pmid=4059390| issue=6| s2cid=27846946}} although in males the hormone testosterone may suppress their sense of smell somewhat.{{Citation| last1=Jechura| first1=T.| last2=Walsh| first2=J. | first3=T.| year=2003| title=Testosterone suppresses circadian responsiveness to social cues in the diurnal rodent Octodon degus| journal=Journal of Biological Rhythms| volume=18| pages=43–50| doi=10.1177/0748730402239675| pmid=12568243| last3=Lee| issue=1| s2cid=40262270| doi-access=free}}

File:Degu father.JPG

Common degus are seasonal breeders; the breeding season for wild degus begins in the Chilean autumn when day and night are roughly equal,{{Citation| last1=Ebensperger| first1=L.A.| last2=Caiozzi| first2=A.| year=2002| title=Male degus, Octodon degus, modify their dustbathing behaviour in response to social familiarity of previous dustbathing marks| journal=Revista Chilena de Historia Natural| volume=75| pages=157–163| doi=10.4067/S0716-078X2002000100015| issn=0716-078X| doi-access=free}} with pups born in early to mid-spring.{{Citation| last1=Bozinovic| first1=F.| last2=Bacigalupe| first2=L.| last3=Vasquez| first3=R.| last4=Visser| first4=H.| last5=Veloso| first5=C.| last6=Kenagy| first6=G.| year=2004| title=Cost of living in free-ranging degus (Octodon degus): Seasonal dynamics of energy expenditure| journal=Comparative Biochemistry and Physiology A| volume=137| pages=597–604| doi=10.1016/j.cbpb.2003.11.014| pmid=15123196| issue=3}} Female degus are pregnant for approximately ninety days,{{Citation| last1=Woods| first1=C.| last2=Boraker| first2=D.| url=http://www.science.smith.edu/departments/Biology/VHAYSSEN/msi/pdf/i0076-3519-067-01-0001.pdf| date=21 November 1975| title=Octodon degus| journal=Mammalian Species| issue=67|pages=1–5| doi=10.2307/3503820| jstor=3503820| s2cid=253992625}}{{Citation| last1=Brown| first1=C.| last2=Donnelly| first2=T.| year=2001| title=Cataracts and reduced fertility in degus (Octodon degus): Contracts secondary to diabetes mellitus| journal=Lab Animal | volume=30| pages=25–26| issn=0093-7355}} 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;{{Citation| last1=Long| first1=C.V.| last2=Ebensperger| first2=L.A.| year=2009| title=Pup growth rates and breeding female weight changes in two populations of captive bred degus (Octodon degus), a precocial caviomorph rodent| journal=Reprod Domest Anim.| volume=45| issue=6| pages=975–82| doi=10.1111/j.1439-0531.2009.01470.x| issn=0936-6768 | pmid=19497026}} litters contain an average of six pups, but size can range from one or two up to twelve young. Common degu pups are born relatively precocial, fully furred and with eyes open, and their auditory and visual systems are functional at birth.{{Citation| last1=Reynolds| first1=T.| last2=Wright| first2=J.| year=1979| title=Early postnatal physical and behavioural development of degus (Octodon degus)| journal=Lab Animal | volume=13| pages=93–9| doi=10.1258/002367779780943576| issue=2| pmid=480906| s2cid=22769488| doi-access=free}} 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.{{cite web|url=https://www.exoticnutrition.com/breeding-degus.aspx|title=Breeding Degus|website=Exoticnutrition.com|access-date=20 May 2019}}

Unlike some other octodontids, common degus are diurnal{{Citation| last1=Kenagy| first1=G.| last2=Nespolo| first2=R.| last3=Vasquez| first3=R.| last4=Bozinovic| first4=F.| year=2002| title=Daily and seasonal limits of time and temperature to activity of degus| journal=Revista Chilena de Historia Natural| volume=75| pages=567–581| doi=10.4067/S0716-078X2002000300008| issn=0716-078X| issue=3| doi-access=free}} (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.{{Citation| last1=Cha'vez| first1=A.| last2=Bozinovic| first2=F.| last3=Peich| first3=F.| last4=Palacios| first4=A.| year=2003| title=Retinal spectral sensitivity, fur coloration and urine reflectance in the genus Octodon (Rodentia): Implications for visual ecology| journal=Investigative Ophthalmology & Visual Science| volume=44| pages=2290–2296| doi=10.1167/iovs.02-0670| issue=5| pmid=12714673| doi-access=free}} 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.{{Citation| last1=Palacios| first1=A.| last2=Bozinovic| first2=F.| year=2003| title=An "enactive" approach to ingtegrative and comparative biology: Thoughts on the table| journal=Biol. Res.| volume=36| pages=101–105| doi=10.4067/S0716-97602003000100008| issn=0716-9760| pmid=12795209| issue=1| doi-access=free}}

Diet

File:2007-12-09 (20) Degu.JPG

Common degus are strictly herbivorous, in the wild feeding on grasses and browsing the leaves of shrubs, though they will also take seeds.{{Citation| last1=Bozinovic| first1=F.| last2=Gallardo| first2=P.A.| last3=Visser| first3=G.H.| last4=Cortés| first4=A.| year=2003| title=Seasonal acclimatization in water flux rate, urine osmolality and kidney water channels in free-living degus: Molecular mechanisms, physiological processes and ecological implications| journal=J Exp Biol| volume=206| pages=2959–2966| doi=10.1242/jeb.00509| pmid=12878664| issue=Pt 17| doi-access=free}} Throughout much of the year forage is dried and so common degus are specially adapted to a very high fibre intake,{{Citation| last=Langer| first=P.| year=2002| title=The digestive tract and life history of small mammals| journal=Mammal Review| volume=32| pages=107–131| doi=10.1046/j.1365-2907.2002.00101.x|issue=2| doi-access=free}} and this varies between food types and environmental conditions.{{Citation| last1=Gutiérrez| first1=J.| last2=Bozinovic| first2=F.| year=1998| title=Diet selection in captivity by a generalist herbivorous rodent (Octodon degus) from the Chilean coastal desert| journal=Journal of Arid Environments| volume=39| pages=601–607| doi=10.1006/jare.1998.0412| issue=4| bibcode=1998JArEn..39..601G}} Like some other herbivores such as rabbits, they perform coprophagy (faecal reingestion) so as to extract more nutrition from their diet.{{Citation| last1=Kenagy| first1=G.| last2=Veloso| first2=C.| last3=Bozinovic| first3=F.| year=1999| title=Daily rhythms of food intake and feces reingestion in the degu, an herbivorous Chilean rodent: Optimizing digestion through coprophagy| journal=Physiological and Biochemical Zoology| volume=72| pages=78–86| doi=10.1086/316644| pmid=9882606| issue=1| s2cid=32432487}} This also serves to maintain healthy gut function during times when food is scarce. Although they are active by day, in high summer they do not leave their burrows in the middle of the day and instead emerge to forage in the mornings and evenings.

Common degus have an intolerance of dietary sugar. They 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.{{cite journal |last1=Opazo |first1=J.C. |last2=Soto-Gamboa |first2=M. |last3=Bozinovic |first3=F. |year=2004 |title=Blood glucose concentration in caviomorph rodents |journal=Comp. Biochem. Physiol. A |volume=137 |issue=1 |pages=57–64 |doi=10.1016/j.cbpb.2003.09.007|pmid=14720591 }} This is thought to be due to evolutionary pressure arising from the lack of availability of free sugars in the degu's natural environment.{{cite journal |last1=Nishi |first1=M. |last2=Steiner |first2=D. |year=2003 |title=Cloning of complementary DNA's encoding islet amyloid polypeptide, insulin, and glucagon precursors from a New World rodent, the degu, Octodon degus |journal=Molecular Endocrinology |volume=4 |pages=1192–8 |doi=10.1210/mend-4-8-1192 |pmid=2293024 |issue=8 |doi-access=free}} 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.{{citation needed|date=November 2011}}

Research subjects

File:Degu Dolly.jpg

Common degus are research subjects due to their relationship with sugar and diabetes, but are also studied for a 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. Common degus have also been found to spontaneously stack objects in order of decreasing size. In both cases, it is the first time these behaviours have been recorded in animals other than apes and birds.{{Citation| last1=Tokimoto| first1=N.| last2=Okanoya| first2=K.| year=2004| title=Spontaneous construction of "Chinese boxes" by degus (Octodon degus): A rudiment of recursive intelligence?| journal=Japanese Psychological Research| volume=46| pages=255–261| doi=10.1111/j.1468-5584.2004.00257.x| issue=3| doi-access=free}}

Another 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.{{Citation| last2=Edgar| first2=D. M.| last1=Kas| first1=M. J. H.| s2cid=18503215| year=2000| title=Photic phase response curve in Octodon degus: Assessment as a function of activity phase preference| journal=American Journal of Physiology| volume=278| issue=5| pages=R1385–1389|pmid=10801311| doi=10.1152/ajpregu.2000.278.5.R1385| doi-access=free}} Common degus can take cues that do not relate to day length, such as temperature,{{Citation| last1=Kas| first1=M.J.| last2=Edgar| first2=D.M.| year=1998| title=Crepuscular rhythms of EEG sleep-wake in a hystricomorph rodent, Octodon degus| journal=J. Biol. Rhythms| volume=13| pages=9–17| doi=10.1177/074873098128999871| pmid=9486839| issue=1| s2cid=32894633}} melatonin levels{{Citation| last1=Morris| first1=L.G.| last2=Tate| first2=B.L.| year=2007| title=Phase response curve to melatonin in a putatively diurnal rodent, Octodon degus| journal= Chronobiol. Int.| volume=24| pages=407–411| doi=10.1080/07420520701420352| pmid=17612940| issue=3| s2cid=13223071}} and scents from other degus{{Citation| last1=Jechura| first1=T.J.| last2=Mahoney| first2=M.M.| last3=Stimpson| first3=C.D.| last4=Lee| first4=T.M.| s2cid=7354002| year=2006| title=Odor-specific effects on reentrainment following phase advances in the diurnal rodent, Octodon degus| journal=Am. J. Physiol. Regul. Integr. Comp. Physiol.| volume=291| pages=R1808–1816| doi=10.1152/ajpregu.00005.2006| issn=0363-6119| pmid=16840658| issue=6}} to adjust their rhythms.

Common degus are also used in development and aging studies. Separation anxiety caused by separating degu 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.{{Citation| last1=Zehle| first1=S.| last2=Bock| first2=J.| last3=Jezierski| first3=G.| last4=Gruss| first4=M.| last5=Braun| first5=K.| year=2007| title=Methylphenidate treatment recovers stress-induced elevated dendritic spine densities in the rodent dorsal anterior cingulate cortex| journal=Dev. Neurobiol.| volume=67| pages=1891–1900| doi=10.1002/dneu.20543| pmid=17874461| issue=14| s2cid=25698865}} In elderly common degus, neural markers have been discovered which are similar to those in humans with Alzheimer's disease, which is the first time this has been seen in a wild-type rodent.{{Citation| last1=Inestrosa| first1=N.C.| last2=Reyes| first2=A.E.| last3=Chacon| first3=M.A.| last4=Cerpa| first4=W.| last5=Villalon| first5=A.| last6=Montiel| first6=J.| last7=Merabachvili| first7=G.| last8=Aldunate| first8=R.| last9=Bozinovic| first9=F.| last10=Aboitiz| first10=Francisco| year=2004| title=Human-like rodent amyloid-beta-peptide determines Alzheimer pathology in aged wild-type Octodon degus| journal=Neurobiol. Aging| volume=26| pages=1023–8| doi=10.1016/j.neurobiolaging.2004.09.016| pmid=15748782| issue=7| s2cid=29644857| display-authors=8}}

As pets

File:Degus-4er-Bande.jpg

File:Common degu in a cage - 2023 March 7.webm

After initial interest into common degus as research subjects, they have become popular as pets. 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).{{citation needed|date=November 2011}} 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. For this reason, common degus cannot be housed in plastic-bottomed cages typically found in pet stores. Lining the floors of a degu enclosure with grass mats or a soft fabric prevents infections known as bumblefoot.{{citation needed|date=December 2010}}

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. The common degu's tail skin and tuft 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, and as such pulling on it or picking up a degu by the tail is not recommended. When tail shedding occurs, common degus will chew off the damaged portion. This can reduce the chances of infection.{{citation needed|date=April 2018}}

Common degus often "groom" their human owners with a gentle nibbling action, and will bond with people that spend time with them. Common degus need regular sand baths, like Chinchillas need dust baths, to keep their coats healthy and free from grease. They should have access to these baths regularly, preferably two or three times a week for half an hour at a time. However, daily sand bathing can make their coats soiled.{{citation needed|date=April 2018}}

=Prohibitions=

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,{{Cite web|url=https://www.wildlife.ca.gov/living-with-wildlife/restricted-pet-species|title=Why can't I have a [...] in California?|last=CDFW|first=California Department of Fish and Wildlife|date=2018|website=Wildlife.ca.gov|access-date=2019-04-11}} Utah,{{cite web|url=https://rules.utah.gov/publicat/code/r657/r657-003.htm#T24|title=UT Admin Code R657-3. Collection, Importation, Transportation, and Possession of Animals. April 1, 2019|website=Rules.utah.gov|access-date=20 May 2019}} Georgia, Connecticut,{{cite web|url=https://eregulations.ct.gov/eRegsPortal/Browse/getDocument?guid={D0E38E56-0000-CCCD-B87B-ABCD1F121231|title=Regulations of Connecticut State Agencies : TITLE 26. Fisheries & Game|website=Eregulations.ct.gov|access-date=20 May 2019}} and Alaska.{{cite web|url=https://www.animalhub.com/10-cool-facts-degus/|title=10 Facts That Make Degus The Coolest Pet Ever!|date=6 March 2016|website=Animalhub.com|access-date=20 May 2019}}