Editing Sugar glider (section)

==Biology and behaviour==
[[File:Sugarglider hp.jpg|175px|thumb|right|Sugar gliders' hind feet are adapted to firmly grasp surfaces such as this rock wall]]

===Gliding===
The sugar glider is one of a number of [[Gliding possum|volplane (gliding) possums]] in Australia. It glides with the fore- and hind-limbs extended at right angles to the body, with feet flexed upwards.<ref name=Jackson(1999) /> The animal launches itself from a tree, spreading its limbs to expose the gliding membranes. This creates an [[aerofoil]] enabling it to glide {{convert|50|m|yd|abbr=off}} or more.<ref name="Strahan-1983">{{cite book|author=Strahan, the Australian Museum|editor=Ronald|title=Complete book of Australian mammals : the national photographic index of Australian wildlife|year=1983|publisher=Angus & Robertson|location=[Sidney]|isbn=0207144540|edition=1. publ.}}</ref> For every {{convert|1.82|m|abbr=on}} travelled horizontally when gliding, it falls {{convert|1|m|abbr=on}}.<ref name=Jackson(1999) /> Steering is controlled by moving limbs and adjusting the tension of the gliding membrane; for example, to turn left, the left forearm is lowered below the right.<ref name=Jackson(1999) />

This form of [[arboreal locomotion]] is typically used to travel from tree to tree; the species rarely descends to the ground. Gliding provides three dimensional avoidance of arboreal predators, and minimal contact with ground dwelling predators; as well as possible benefits in decreasing time and energy consumption<ref name=Nagy(1985)>{{cite journal|last1=Nagy|first1=K. A.|last2=Suckling|first2=G. C.|title=Field energetics and water balance of sugar gliders, "Petaurus breviceps" (Marsupialia: Petauridae) |journal=Australian Journal of Zoology |date=1985 |volume=33 |issue=5|pages=683–691 |doi=10.1071/ZO9850683}}</ref> spent foraging for nutrient poor foods that are irregularly distributed.<ref>{{cite journal |last1=Byrnes |first1=G |last2=Spence |first2=A |title=Ecological and biomechanical insights into the evolution of gliding in mammals|journal=Integrative and Comparative Biology |date=2011 |volume=51 |issue=6 |pages=991–1001 |doi=10.1093/icb/icr069 |pmid=21719434|doi-access=free }}</ref> Young carried in the pouch of females are protected from landing forces by the [[septum]] that separates them within the pouch.<ref name=Jackson(1999) />

===Torpor===
Sugar gliders can tolerate ambient air temperatures of up to {{convert|40|°C|°F}} through behavioural strategies such as licking their coat and exposing the wet area, as well as drinking small quantities of water.<ref name=smith(73) />
In cold weather, sugar gliders will huddle together to avoid heat loss, and will enter [[torpor]] to conserve energy.<ref name=Kortner(2000) /> Huddling as an energy conserving mechanism is not as efficient as torpor.<ref name=Kortner(2000) /> Before entering torpor, a sugar glider will reduce activity and body temperature normally in order to lower energy expenditure and avoid torpor.<ref name="arjournals.annualreviews.org">{{cite journal |first=Fritz |last=Geiser |title=Metabolic Rate and Body Temperature Reduction During Hibernation and Daily Torpor |volume=66 |issue=1 |pages=239–274 |year=2004|doi=10.1146/annurev.physiol.66.032102.115105 |journal=Annual Review of Physiology |pmid=14977403|s2cid=22397415 }}</ref><ref name="ReferenceA">{{cite journal |first=Nereda |last=Christian |author2=Fritz Geiser  |title=To use or not to use torpor? Activity and body temperature as predictors |journal=Naturwissenschaften |volume=94 |issue=6 |pages=483–487 |year= 2007 |doi=10.1007/s00114-007-0215-5 |pmid=17252241|bibcode=2007NW.....94..483C |s2cid=24061894 }}</ref> With energetic constraints, the sugar glider will enter into daily torpor for 2–23 hours while in rest phase.<ref name=Kortner(2000) /> 
Torpor differs from [[hibernation]] in that torpor is usually a short-term daily cycle.  Entering torpor saves energy for the animal by allowing its body temperature to fall to a minimum of {{convert|10.4|°C|°F}}<ref name=Kortner(2000) /> to {{convert|19.6|°C|°F}}.<ref name="springerlink1">{{cite journal |first=Fritz |last=Geiser |author2=Joanne C. Holloway |author3=Gerhard Körtner |title=Thermal biology, torpor and behaviour in sugar gliders: a laboratory-field comparison |journal=Journal of Comparative Physiology B |volume=177 |issue=5 |pages=495–501 |year=2007 |doi=10.1007/s00360-007-0147-6 |pmid=17549496 |s2cid=24469410 }}</ref> When food is scarce, as in winter, heat production is lowered in order to reduce energy expenditure.<ref>{{cite journal |pmid=11765973 | volume=171 | issue=8 | title=Seasonal changes in the thermoenergetics of the marsupial sugar glider, ''Petaurus breviceps'' |date=November 2001 | journal=J. Comp. Physiol. B | pages=643–50 | doi=10.1007/s003600100215 | last1 = Holloway | first1 = JC | last2 = Geiser | first2 = F| s2cid=1008750 }}</ref> With low energy and heat production, it is important for the sugar glider to peak its body mass by fat content in the autumn (May/June) in order to survive the following cold season. In the wild, sugar gliders enter into daily torpor more often than sugar gliders in captivity.<ref name="ReferenceA"/><ref name="springerlink1"/> The use of torpor is most frequent during winter, likely in response to low ambient temperature, rainfall, and seasonal fluctuation in food sources.<ref name=Kortner(2000)>{{cite journal|last1=Kortner|first1=G|last2=Geiser|first2=F|title=Torpor and activity patterns in free-ranging sugar gliders "Petaurus breviceps" (Marsupialia)|journal=Oecologia|date=2000|volume=123|issue=3|pages=350–357|doi=10.1007/s004420051021|pmid=28308589|bibcode=2000Oecol.123..350K|s2cid=10103980}}</ref>

===Diet and nutrition===
[[File:Petaurus breviceps Gould.jpg|thumb|1863 illustration by [[John Gould]]]]
Sugar gliders are seasonally adaptive omnivores with a wide variety of foods in their diet, and mainly forage in the lower layers of the forest canopy.<ref name="Jackson(2k)"/><ref name=smith87>{{cite journal |last1=Smith |first1=AP |title=Diet and feeding strategies of the marsupial glider in temperate Australia |journal=Journal of Animal Ecology |date=1982 |volume=51 |issue=1 |pages=149–166 |doi=10.2307/4316|jstor=4316 }}</ref> Sugar gliders may obtain up to half their daily water intake through drinking rainwater, with the remainder obtained through water held in its food.<ref name=Nagy(1985) /> In summer they are primarily [[insectivorous]], and in the winter when insects (and other [[arthropod]]s) are scarce, they are mostly [[Exudate|exudativorous]] (feeding on [[acacia gum]], [[eucalyptus]] [[Plant sap|sap]], [[manna (disambiguation)|manna]],{{efn| When dried, an [[exudate]] (such as sap) becomes [[Crystallization|crystallized]] and is referred to as ''manna'',<ref>{{cite web|title=manna|url=http://wordnetweb.princeton.edu/perl/webwn?o2=&o0=1&o8=1&o1=1&o7=&o5=&o9=&o6=&o3=&o4=&s=manna&i=1&h=100#c|work=WordNet Search – 3.1|publisher=WordNet. Princeton University|access-date=19 December 2012|quote=(n) manna (hardened sugary exudation of various trees) : Synset (semantic) relations, ''direct hypernym'' (n) sap (a watery solution of sugars, salts, and minerals that circulates through the vascular system of a plant)}}</ref><ref>{{cite book|editor-last=Pickert|editor-first=Executive: Joseph P.|title=The American heritage dictionary of the English language.|year=1992|publisher=Houghton Mifflin|location=Boston|isbn=0395825172|edition=4th|page=[https://archive.org/details/americanheritage0000unse_a1o7/page/1065 1065]|quote=manna ''n''. 4. The dried exudate of certain plants|url-access=registration|url=https://archive.org/details/americanheritage0000unse_a1o7/page/1065}}</ref> which is consumed by sugar gliders.<ref>{{cite web|editor-last=Cianciolo|author=Janine M., DVM|title=Sugar Glider Nutrition|url=http://www.sugar-gliders.com/sugar-glider-diet.htm|work=Past Newsletters|publisher=SunCoast Sugar Gliders|quote=Sugar gliders eat manna in the wild. Manna is a crusty sugar left from where sap flowed from a wound in a tree trunk or branch.}}</ref>}} [[Honeydew (secretion)|honeydew]] or [[lerp (biology)|lerp]]).<ref>{{cite web|title=The Sugar Glider Diet|url=http://www.sugarglidercorner.com/category/sugar-glider-diet/|work=Sugar Glider Diet Archives|publisher=Sugar Glider Cage|access-date=6 October 2012|archive-url=https://web.archive.org/web/20120824125424/http://www.sugarglidercorner.com/category/sugar-glider-diet/|archive-date=24 August 2012|url-status=dead}}</ref> Sugar gliders have an enlarged [[caecum]] to assist in digestion of [[complex carbohydrates]] obtained from gum and sap.<ref>{{cite journal |last1=Dierenfeld |first1=Ellen |title=Feeding behavior and nutrition of the Sugar Glider (''Petaurus breviceps'')|journal=Veterinary Clinics of North America: Exotic Animal Practice |date=2009 |volume=12 |issue=2 |pages=209–215 |doi=10.1016/j.cvex.2009.01.014|pmid=19341949 }}</ref>
 
To obtain sap or gum from plants, sugar gliders will strip the bark off trees or open bore holes with their teeth to access stored liquid.<ref name="smith87"/> Little time is spent [[foraging]] for insects, as it is an energetically expensive process, and sugar gliders will wait until insects fly into their habitat, or stop to feed on flowers.<ref name="smith87"/>
Gliders consume approximately 11 g of dry food matter per day.<ref name=Nagy(1985) /> This equates to roughly 8% and 9.5% of body weight for males and females, respectively.

They are [[opportunistic feeder]]s and can be [[Carnivore|carnivorous]], preying mostly on lizards and small birds.  They eat many other foods when available, such as nectar, acacia seeds, bird eggs, pollen, fungi and native fruits.<ref>{{cite web |last=McLeod, DVM |first=Lianne |title=Feeding Sugar Gliders / Nutritional Needs and Sample Diets |url=http://exoticpets.about.com/cs/sugargliders/a/sgfeeding.htm |publisher=About.com |access-date=3 October 2012 |archive-date=25 August 2012 |archive-url=https://web.archive.org/web/20120825030756/http://exoticpets.about.com/cs/sugargliders/a/sgfeeding.htm |url-status=dead }}</ref><ref>{{cite web |title=Natural Diet |url=http://www.sugarglider.com/gliderpedia/index.asp?NaturalDiet |work=Gliderpedia |publisher=SugarGlider.com |access-date=2012-11-02}}</ref> Pollen can make up a large portion of their diet, therefore sugar gliders are likely to be important [[pollinator]]s of ''[[Banksia]]'' species.<ref name=vanTets>{{cite journal |last1=van Tets |first1=Ian G. |last2=Whelan |first2=Robert J. |title=Banksia pollen in the diet of Australian mammals |journal=Ecography |date=1997 |volume=20 |issue=5 |pages=499–505 |doi=10.1111/j.1600-0587.1997.tb00418.x|doi-access=free }}</ref>

===Reproduction===

Like most [[marsupial]]s, female sugar gliders have two [[Ovary|ovaries]] and two [[Uterus|uteri]]; they are [[polyestrous]], meaning they can go into [[Estrus|heat]] several times a year.<ref name=suckling1 /> The female has a [[Pouch (marsupial)|marsupium]] (pouch) in the middle of her abdomen to carry offspring.<ref name="Hilltop"/> The pouch opens anteriorly, and two lateral pockets extend posteriorly when young are present. Four nipples are usually present in the pouch, although reports of individuals with two nipples have been recorded.<ref name=smith(73) /> Male sugar gliders have two pairs of [[Bulbourethral gland|bulbourethral glands]]<ref>{{Cite book |last1=Quesenberry |first1=Katherine |url=https://books.google.com/books?id=t-_eDwAAQBAJ&pg=PA387 |title=Ferrets, Rabbits and Rodents - E-Book: Ferrets, Rabbits and Rodents - E-Book |last2=Mans |first2=Christoph |last3=Orcutt |first3=Connie |date=2020-04-24 |publisher=Elsevier Health Sciences |isbn=978-0-323-48434-3 |language=en}}</ref> and a [[marsupial penis|bifurcated penis]] to correspond with the two uteri of females.<ref>{{cite journal |last1=Morges |first1=Michelle A. |last2=Grant |first2=Krystan R. |last3=MacPhail |first3=Catriona M. |last4=Johnston |first4=Matthew S. |title=A Novel Technique for Orchiectomy and Scrotal Ablation in the Sugar Glider (''Petaurus breviceps'') |journal=Journal of Zoo and Wildlife Medicine |date=March 2009 |volume=40 |issue=1 |pages=204–206 |doi=10.1638/2007-0169.1|pmid=19368264 |s2cid=24253225 }}</ref>

The age of sexual maturity in sugar gliders varies slightly between the males and females. Males reach maturity at 4 to 12 months of age, while females require from 8 to 12 months. In the wild, sugar gliders breed once or twice a year depending on the climate and habitat conditions, while they can breed multiple times a year in captivity as a result of consistent living conditions and proper diet.<ref name="Hilltop"/>

A sugar glider female gives birth to one (19%) or two (81%) babies (joeys) per litter.<ref name=suckling1 /> The gestation period is 15 to 17 days, after which the tiny joey {{convert|0.2|g|oz|abbr=on}} will crawl into a mother's pouch for further development. They are born largely undeveloped and furless, with only the [[olfaction|sense of smell]] being developed.  The mother has a scent gland in the external marsupium to attract the sightless joeys from the uterus.<ref name = "Tynes(2010)">{{cite book|editor1-last=Tynes|editor1-first=Valarie V.|title=Behavior of exotic pets|date=2010|publisher=[[Wiley-Blackwell|Blackwell Pub.]]|location=Chichester, West Sussex|isbn=9780813800783|edition=1st|chapter=Sugar gliders}}</ref> Joeys have a continuous arch of cartilage in their [[shoulder girdle]] which disappears soon after birth; this supports the forelimbs, assisting the climb into the pouch.<ref>{{cite web|last=Antinoff |first=Natalie |title=Practical anatomy and physical examination: Ferrets, rabbits, rodents, and other selected species (Proceedings) |url=http://veterinarycalendar.dvm360.com/avhc/article/articleDetail.jsp?id=638213&sk=&date=&%0A%09%09%09&pageID=5 |date=August 2009 |publisher=CVC in Kansas City Proceedings |access-date=11 November 2012 |url-status=dead |archive-url=https://web.archive.org/web/20130724140555/http://veterinarycalendar.dvm360.com/avhc/article/articleDetail.jsp?id=638213&sk=&date=&%0A%09%09%09&pageID=5 |archive-date=24 July 2013 }}</ref> Young are completely contained in the pouch for 60 days after birth, wherein [[mammae]] provide nourishment during the remainder of development.<ref name="Tynes(2010)"/> Eyes first open around 80 days after birth, and young will leave the nest around 110 days after birth.<ref name=smith(73) /> By the time young are [[Weaning|weaned]], the [[Endotherm|thermoregulatory system]] is developed, and in conjunction with a large body size and thicker fur, they are able to regulate their own body temperature.<ref name=holloway(2000)>{{cite journal|last1=Holloway|first1=Joanne C.|last2=Geiser|first2=Fritz|title=Development of thermoregulation in the sugar glider Petaurus breviceps (Marsupialia: Petauridae)|journal=Journal of Zoology|date=November 2000|volume=252|issue=3|pages=389–397|doi=10.1111/j.1469-7998.2000.tb00634.x|doi-access=free}}</ref>

Breeding is seasonal in southeast Australia, with young only born in winter and spring (June to November).<ref name=suckling1 /> Unlike animals that move along the ground, the sugar glider and other gliding species produce fewer, but heavier, offspring per litter.  This allows female sugar gliders to retain the ability to glide when pregnant.<ref>{{cite journal|last1=Fokidis|first1=H|last2=Risch|first2=T|date=2008|title=The burden of motherhood: gliding locomotion in mammals influences maternal reproductive investment|journal=Journal of Mammalogy|volume=89|issue=3|pages=617–625|doi=10.1644/07-MAMM-A-116R1.1|doi-access=free}}</ref>

===Socialisation===
Sugar gliders are highly social animals. They live in family groups or [[Colony (biology)|colonies]] consisting of up to seven adults, plus the current season's young. Up to four age classes may exist within each group, although some sugar gliders are solitary, not belonging to a group.<ref name=suckling1 /> They engage in [[social grooming]], which in addition to improving hygiene and health, helps bond the colony and establish group identity.

Within social communities, there are two codominant males who suppress subordinate males, but show no aggression towards each other. These co-dominant pairs are more related to each other than to subordinates within the group; and share food, nests, mates, and responsibility for scent marking of community members and territories.<ref name=Klettenheimer1>{{cite journal|last1=Klettenheimer|first1=B|last2=Temple-Smith|first2=P|last3=Sofrondis|first3=G|title=Father and son sugar gliders: more than a genetic coalition?|journal=Journal of Zoology|date=1997|volume=242|issue=4|pages=741–750|doi=10.1111/j.1469-7998.1997.tb05823.x}}</ref>

Territory and members of the group are marked with saliva and a scent produced by separate glands on the forehead and chest of male gliders. Intruders who lack the appropriate scent marking are expelled violently.<ref name="dpiwtas"/> Rank is established through scent marking; and fighting does not occur within groups, but does occur when communities come into contact with each other.<ref name=smith(73) /> Within the colony, no fighting typically takes place beyond threatening behaviour.<ref>Pasatta, J. (1999). [http://animaldiversity.ummz.umich.edu/accounts/Petaurus_breviceps/ "Petaurus breviceps" (On-line)], Animal Diversity Web. Accessed 10 November 2012</ref> Each colony defends a territory of about {{convert|1|hectare|acre}} where eucalyptus trees provide a [[staple food]] source.{{citation needed|date=January 2020}}

Sugar gliders are one of the few species of [[mammal]]s that exhibit [[Paternal care|male parental care]].<ref name=Goldingay(2010)>{{cite journal|last1=Goldingay|first1=R. L.|title=Direct male parental care observed in wild sugar gliders|journal=Australian Mammalogy|date=2010|volume=32|issue=2|pages=177–178|doi=10.1071/AM10009}}</ref> The oldest codominant male in a social community shows a high level of parental care, as he is the probable father of any offspring due to his social status.
This paternal care evolved in sugar gliders as young are more likely to survive when [[parental investment]] is provided by both parents.<ref name=Goldingay(2010) /> In the sugar glider, biparental care allows one adult to huddle with the young and prevent [[hypothermia]] while the other parent is out foraging, as young sugar gliders aren't able to [[Thermoregulation|thermoregulate]] until they are 100 days old (3.5 months).<ref name=Goldingay(2010) />

Communication in sugar gliders is achieved through vocalisations, visual signals and complex chemical odours.<ref name=smith(73) /> Chemical odours account for a large part of communication in sugar gliders, similar to many other nocturnal animals. Odours may be used to mark territory, convey health status of an individual, and mark rank of community members. Gliders produce a number of vocalisations including barking and hissing.<ref>{{Cite journal |last=Johnson |first=Dan H. |date=20 May 2011 |title=Hedgehogs and Sugar Gliders: Respiratory Anatomy, Physiology, and Disease |url=https://doi.org/10.1016/j.cvex.2011.03.006 |journal=Veterinary Clinics of North America: Exotic Animal Practice |volume=14 |issue=2 |pages=267-85, vi|doi=10.1016/j.cvex.2011.03.006 |pmid=21601815 |url-access=subscription }}</ref>