Editing Impala (section)

===Reproduction===
[[File:Fighting impalas brighten.jpg|thumbnail|alt=Males lock horns in a mating fight|Two males fighting for [[dominance (ethology)|dominance]]]]
Males are [[sexual maturity|sexually mature]] by the time they are a year old, though successful mating generally occurs only after four years. Mature males start establishing territories and try to gain access to females. Females can conceive after they are a year and a half old; [[oestrus]] lasts for 24 to 48 hours, and occurs every 12–29 days in non-pregnant females.<ref name="Nowak" /> The annual three-week-long rut (breeding season) begins toward the end of the [[wet season]], typically in May. [[Gonad]]al growth and [[hormone]] production in males begin a few months before the breeding season, resulting in greater aggressiveness and territoriality.<ref name="estes" /> The [[bulbourethral gland]]s are heavier, [[testosterone]] levels are nearly twice as high in territorial males as in bachelors,<ref>{{cite journal |last1 = Bramley |first1 = P.S. |last2 = Neaves |first2 = W.B. |title = The relationship between social status and reproductive activity in male impala, ''Aepyceros melampus'' |journal = [[Reproduction (journal)|Journal of Reproduction and Fertility]] |year = 1972 |volume = 31 |issue = 1 |pages = 77–81 |pmid = 5078117 |doi = 10.1530/jrf.0.0310077|url=http://www.reproduction-online.org/content/31/1/77.full.pdf|doi-access = free }}</ref> and the neck of a territorial male tends to be thicker than that of a bachelor during the rut. Mating tends to take place between full moons.<ref name="estes" />
[[File:Impala (Aepyceros melampus) (W1CDR0000514 BD37).ogg|right|thumb|Sounds of rutting male]]
[[Rut (mammalian reproduction)|Rutting]] males fight over dominance, often giving out noisy roars and chasing one another; they walk stiffly and [[Display (zoology)|display]] their neck and horns. Males desist from feeding and allogrooming during the rut, probably to devote more time to garnering females in oestrus;<ref name=hart2/> the male checks the female's urine to ensure that she is in oestrus.<ref>Hart, Lynette A., and Benjamin L. Hart. "[https://www.researchgate.net/profile/Benjamin_Hart4/publication/232525532_Species-specific_patterns_of_urine_investigation_and_flehmen_in_Grant%27s_gazelle_Gazella_granti_Thomson%27s_gazelle_G_thomsoni_impala_Aepyceros_melampus_and_eland_Taurotragus_oryx/links/554522870cf24107d397b00d.pdf Species-specific patterns of urine investigation and flehmen in Grant's gazelle (Gazella granti), Thomson's gazelle (G. thomsoni), impala (Aepyceros melampus), and eland (Taurotragus oryx)]." Journal of Comparative Psychology 101.4 (1987): 299.</ref><ref name=hart2>{{cite journal |last = Mooring |first = M. S. |author2 = Hart, B. L. |title = Differential grooming rate and tick load of territorial male and female impala |journal = [[Behavioral Ecology (journal)|Behavioral Ecology]] |year = 1995 |volume = 6 |issue = 1 |pages = 94–101 |doi = 10.1093/beheco/6.1.94 }}</ref> On coming across such a female, the excited male begins the [[Courtship display|courtship]] by pursuing her, keeping a distance of {{convert|3|-|5|m|ft}} from her. The male flicks his tongue and may nod vigorously; the female allows him to lick her vulva, and holds her tail to one side. The male tries mounting the female, holding his head high and clasping her sides with his forelegs. Mounting attempts may be repeated every few seconds to every minute or two. The male loses interest in the female after the first copulation, though she is still active and can mate with other males.<ref name="estes" /><ref name="schenkel" />

Gestation lasts six to seven months. Births generally occur in the midday; the female will isolate herself from the herd when labour pain begins.<ref name=jarman>{{cite book |last = Jarman |first = M.V. |title = Impala Social Behaviour: Territory, Hierarchy, Mating, and the Use of Space |year = 1979 |publisher = Parey |location = Berlin, Germany |isbn = 978-3-489-60936-0 |pages = 1–92 |oclc = 5638565}}</ref> The perception that females can delay giving birth for an additional month if conditions are harsh may however not be realistic.<ref>{{cite web|url=http://blog.londolozi.com/2016/11/can-impala-really-delay-their-births|first=Shaun|last=D'Araujo|title=Can Impala Really Delay Their Births?|website=Londolozi Blog|date=20 November 2016}}</ref> A single calf is born, and is immediately concealed in cover for the first few weeks of its birth. The fawn then joins a nursery group within its mother's herd. Calves are suckled for four to six months; young males, forced out of the group, join bachelor herds, while females may stay back.<ref name="estes" />