Editing Addax (section)

==Behavior and ecology==
Addax herds contain both males and females, and have from five to 20 members. They will generally stay in one place and only wander widely in search of food. The herd is usually formed around one dominant male.<ref name=":0" /> In captivity, males show signs of territoriality and mate guarding while captive females establish dominance hierarchies, with oldest females holding highest rank <ref name=Krausman2007/>  Herds are more likely to be found along the northern edge of the tropical rain system during the summer and move north as winter falls.  They are able to track rainfall and will head for these areas where vegetation is more plentiful. Males are territorial and guard females,<ref name=Spevak1993>{{cite journal |author=Spevak, E.M. |year=1993 |title=Species survival plan contributions to research and reintroduction of the addax ''Addax nasomaculatus'' |journal=International Zoo Yearbook |volume=32 |issue=1 |pages=91–98 |doi=10.1111/j.1748-1090.1993.tb03520.x}}</ref> while the females establish their own dominance hierarchies.<ref name=Reason1988>{{cite journal |author1=Reason, R.C. |author2=Laird, E.W. |year=1988 |title=Determinants of dominance in captive female addax (''Addax nasomaculatus'') |journal=Journal of Mammalogy |volume=69 |issue=2 |jstor=1381391 |pages=375–377 |doi=10.2307/1381391}}</ref>

Due to its slow movements, the addax is an easy target for [[Predation|predators]] such as [[human]]s, [[lion]]s, [[leopard]]s, [[cheetah]]s and [[African wild dog]]s. [[Caracal]]s, [[serval]]s and [[hyena]]s attack calves. The addax is normally not aggressive, though individuals may charge if they are disturbed.<ref name=Krausman2007/>

===Adaptations===
[[File:Addax-1-Zachi-Evenor.jpg|thumb|Addaxes grazing in dry conditions]]
The addax is amply suited to live in the deep desert under extreme conditions. It can survive without free water almost indefinitely, because it gets moisture from its food and dew that condenses on plants. Scientists{{who|date=December 2015}} think the addax has a special lining in its stomach that stores water in pouches to use in times of [[dehydration]]. It also produces highly concentrated [[urine]] to conserve water.<ref name=arkive>{{cite web|title=Addax|url=http://www.arkive.org/addax/addax-nasomaculatus/#text=All |work=Wildscreen |publisher=ARKive|access-date=20 June 2012 |archive-url=https://web.archive.org/web/20120618050555/http://www.arkive.org/addax/addax-nasomaculatus/#text=All#text=All |archive-date=18 June 2012|url-status=dead|df=dmy-all}}</ref> The pale colour of the coat reflects radiant heat, and the length and density of the coat helps in [[thermoregulation]]. In the day the addax huddles together in shaded areas, and on cool nights rests in sand hollows. These practices help in dissipation of body heat and saving water by cooling the body through evaporation.<ref name=Krausman2007/>

In a study, eight addaxes on a diet of grass hay (''[[Chloris gayana]]'') were studied to determine the retention time of food from the digestive tract. It was found that food retention time was long, taken as an adaptation to a diet including a high proportion of slow fermenting grasses; while the long fluid retention time could be interpreted to be due to water-saving mechanisms with low water turnover and a roomy rumen.<ref name=hummel>{{cite journal |last=Hummel |first=J. |author2=Steuer, P. |author3=Südekum, K.-H. |author4=Hammer, S. |author5=Hammer, C. |author6=Streich, W. J.|author7=Clauss, M.|title=Fluid and particle retention in the digestive tract of the addax antelope (''Addax nasomaculatus'') — Adaptations of a grazing desert ruminant|journal=Comparative Biochemistry and Physiology A|year=2008 |volume=149 |issue=2 |pages=142–149 |doi=10.1016/j.cbpa.2007.11.001 |pmid=18083600 |url=http://www.zora.uzh.ch/2368/2/CBP_Addax_Passage_2008V.pdf |access-date=21 March 2019 |archive-date=5 July 2017 |url-status=live |archive-url=https://web.archive.org/web/20170705110034/https://www.zora.uzh.ch/2368/2/CBP_Addax_Passage_2008V.pdf}}</ref>

===Diet===
[[File:Addax mit kalb.jpg|thumb|An addax calf with its mother]]
The addax lives in desert terrain where it eats grasses and leaves of what [[shrubs]], [[leguminous]] herbs and bushes are available. Primarily a [[Grazing (behaviour)|grazer]], its staple foods include ''[[Aristida]]'', ''[[Panicum]]'', and ''[[Stipagrostis]]'', and it will only consume browse, such as leaves of ''[[Acacia]]'' trees in the absence of these grasses.<ref name=hummel /> It also eats perennials which turn green and sprout at the slightest bit of humidity or rain. The addax eats only certain parts of the plant and tends to crop the ''Aristida'' grasses neatly to the same height. By contrast, when feeding on ''Panicum'' grass, the drier outer leaves are left alone while it eats the tender inner shoots and seeds. These [[seeds]] are important part of the addax's diet, being its main source of protein.<ref name="f&w"/>

===Reproduction===
Females are [[sexually mature]] at 2 to 3 years of age and males at about 2 years. Breeding occurs throughout the year, but it peaks during winter and early spring. In the northern Sahara, breeding peaks at the end of winter and the beginning of spring; in the southern Sahara, breeding peaks from September to October and from January to mid-April. Each estrus bout lasts for one or two days.<ref name=Krausman2007/>

In a study, the [[blood serum]] of female addaxes was analyzed through [[immunoassay]] to know about their [[luteal phase]]. [[Estrous cycle]] duration was of about 33 days. During pregnancy, [[Obstetric ultrasonography|ultrasonography]] showed the uterine horns as coiled. The maximum diameters of the [[ovarian follicle]] and the [[corpus luteum]] were {{cvt|15|mm}} and {{cvt|27|mm}}. Each female underwent an [[Anovulatory cycle|anovulatory period]] lasting 39 to 131 days, during which there was no [[ovulation]]. Anovulation was rare in winter, which suggested the effect of seasons on the estrous cycle.<ref name=Asa>{{cite journal |last=Asa |first=C.S. |author2=Houston, E.W. |author3=Fischer, M.T. |author4=Bauman, J.E.|author5=Bauman, K.L. |author6=Hagberg, P.K. |author7= Read, B.W. |title=Ovulatory cycles and anovulatory periods in the addax (''Addax nasomaculatus'') |journal=Journal of Reproduction and Fertility |year=1996 |volume=107 |issue=1 |pages=119–124 |doi=10.1530/jrf.0.1070119 |pmid=8699424 |doi-access=free}}</ref>

[[Pregnancy (mammals)|Gestation period]] lasts 257–270 days (about nine months). Females may lie or stand during the delivery, during which one calf is born. A postpartum estrus occurs after two or three days.<ref name=Densmore1986>{{cite journal |author1=Densmore, M.A. |author2=Kraemer, D.C. |year=1986 |title=Analysis of reproductive data on the addax (''Addax nasomaculatus'') in captivity |journal=International Zoo Yearbook |volume=24 |issue=1 |pages=303–306 | doi=10.1111/j.1748-1090.1985.tb02559.x}}</ref> The calf weighs {{cvt|5|kg}} at birth and is weaned at 23–29 weeks old.<ref name=Manski1991>{{cite journal |author=Manski, D.A. |year=1991 |title=Reproductive behavior of addax antelope |journal=Applied Animal Behaviour Science |volume=29 |issue=1 |pages=39–66 |doi=10.1016/0168-1591(91)90237-r}}</ref>