Animal Diversity Web

Ge­o­graphic Range

Cen­ter of dis­tri­b­u­tion is the south­west­ern African rain­for­est and the wet­ter re­gions of the south­ern sa­vanna. Specif­i­cally Gam­bia to S.W. Ethiopia, south to An­gola, Namibia, N.W. Botswana. (Estes, 1991; Honacki et al., 1982)

• Biogeographic Regions
• ethiopian
  • native

Habi­tat

The si­tatunga is semi­aquatic, and so spe­cial­ized that it oc­curs only in swamps or per­ma­nent marshes. Par­tial to pa­pyrus and phrag­mites within swamps, it may also occur in wet­lands dom­i­nated by bull­rushes, reeds, and sedges. They fre­quent the deep­est parts of the swamp. (Estes, 1991; Nowak, 1991)

• Aquatic Biomes
• lakes and ponds

Phys­i­cal De­scrip­tion

The Si­tatunga, a swamp-dwelling an­te­lope, ex­hibits great elon­ga­tion of the hooves, which have a wide splay and naked pad­like pat­tern. They pos­sess unique flex­i­bil­ity of the joints at the feet, rep­re­sent­ing struc­tural adap­ta­tions for walk­ing on boggy and marshy ground.

Col­oration varies ge­o­graph­i­cally and in­di­vid­u­ally. Males are gray-brown to choco­late-brown, fe­males are brown to bright chest­nut, and calves are bright ru­fous-red, woolly coated, spot­ted, and striped. Adults are long coated and have char­ac­ter­is­tic whiteish marks on the face, ears, cheeks, body, legs, and feet.

Males are con­sid­er­ably larger than fe­males (100 cm tall vs. 75-90 cm tall). Males pos­sess horns rang­ing in length from 508-924 mm. Horns are char­ac­ter­ized by two twists and are ivory tipped. (Estes, 1991; Nowak, 1991)

• Other Physical Features
• endothermic
• homoiothermic
• bilateral symmetry

• Sexual Dimorphism
• male larger
• sexes colored or patterned differently

• Range mass

  50 to 125 kg

  110.13 to 275.33 lb

Re­pro­duc­tion

Breed­ing oc­curs through­out the year, males are polyg­y­nous, and fe­males pro­duce a sin­gle young at an av­er­age in­ter­val of 11.6 months. The mean ges­ta­tion pe­riod is 247 days, and sex­ual ma­tu­rity is at­tained at ap­prox­i­mately 1 yr. by fe­males and 1.5 yrs. by males.

A male ap­proaches a fe­male in a low stretch pos­ture while the fe­male may back away slowly. When the male comes within a few inches of the fe­male, she may sud­denly bound away, caus­ing con­sid­er­able com­mo­tion in the swamp. The male per­sis­tently fol­lows, but al­ways stays be­hind. It is char­ac­ter­is­tic of this species that the male lay his head and neck on the fe­male's back and lifts his forelegs off the ground in a mount­ing at­tempt. The fe­male re­sponds with neck wind­ing, in which her neck an­gles down obliquely and her head turns sharply up, thrust­ing for­ward, up­ward and back with mouth wide open. The male then mounts with his head rest­ing on her back, and her head and neck point for­ward and down.

Fe­males hide their calves on plat­forms in se­cluded dry reeds grow­ing in deep water. Calves are un­able to move slowly and de­lib­er­ately through the swamp like adults, and fol­low their moth­ers closely for sev­eral months only after learn­ing how. A mother feeds near the calf's hid­ing spot, fin­ishes, and walks up to the calf. It licks the young's snout, then moves away. The calf gets up and fol­lows the mother, and she leads it to a pro­tected place where it can suckle. (Estes, 1991; Nowak, 1991)

• Key Reproductive Features
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual

• Range number of offspring

  1 to 2

• Average number of offspring

  1

• Average number of offspring

  1

  AnAge

• Range gestation period

  7.5 to 8.6 months

• Average gestation period

  8.23 months

• Average age at sexual or reproductive maturity (female)
  Sex: female

  401 days

  AnAge

• Parental Investment
• altricial
• precocial
• post-independence association with parents

Lifes­pan/Longevity

• Average lifespan
  Status: captivity

  22.6 years

  AnAge

Be­hav­ior

So­cial or­ga­ni­za­tion: Si­tatunga are semi-so­cial, non­ter­ri­to­r­ial, and seden­tary. Swamps are highly pro­duc­tive ecosys­tems and si­tatun­gas can live at den­si­ties of 55/km^(2) or higher. Fe­males tend to form herds and males as­so­ci­ate to­gether or with fe­males until subadult. As adults, males avoid one an­other.

Ac­tiv­ity: Si­tatun­gas move through the swamp along es­tab­lished path­ways. These have nu­mer­ous side branches lead­ing to feed­ing grounds and neigh­bor­ing river­ine for­est. They are ac­tive both di­ur­nally and noc­tur­nally and may move into marshy land at night. They typ­i­cally feed at any hour in areas where they are pro­tected. They also lie on plat­forms of veg­e­ta­tion that each an­i­mal pre­pares for it­self by re­peated cir­cling and tram­pling. They also stand and ru­mi­nate in the water.

Lo­co­mo­tion: Si­tatun­gas are slow and clumsy land run­ners, but their plung­ing run works well in water. Their broad and splayed hooves keep them from sink­ing in soft ground as deeply as other un­gu­lates. They are usu­ally slow and in­con­spic­u­ous, and are good swim­mers.

Vocal com­mu­ni­ca­tion: Males often bark at night, some­times as an alarm sig­nal, or per­haps as a way of an­nounc­ing their lo­ca­tion. Fe­males have a sin­gle higher-pitched bark. A male fol­low­ing a fe­male in a low stretch may utter a sup­pressed roar. (Estes, 1991)

• Key Behaviors
• motile
• social

Com­mu­ni­ca­tion and Per­cep­tion

• Perception Channels
• tactile
• chemical

Food Habits

Al­chornea cordi­fo­lia, com­mon around Lake Vic­to­ria, pro­vides a fa­vorite browse for si­tatunga. For­ag­ing takes place in both dry land and swamp. Si­tatunga se­lect plants in the flow­er­ing stage. They often emerge at night from swamp­lands to graze on nearby dry land, as well as in ad­ja­cent forests where they browse on fo­liage and creep­ers. Feed­ing ac­tiv­ity is apt to be con­cen­trated in a small area of swamp for many days at a time, then they sud­denly shift to new grounds. Si­tatunga feed while im­mersed up to their shoul­ders and move slowly through the veg­e­ta­tion. Some­times forelegs may be im­mersed while hind legs are el­e­vated. They may rear to reach flow­ers of tall reeds, sedges, grasses and fo­liage, and males have been known to break branches with their horns. When feed­ing on long leaves, a si­tatunga wraps its tongue around a clump, pulls it into its mouth, and crops it with its in­cisors. (Estes, 1991; King­don, 1974)

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Snare trap­pers value Si­tatunga as a food source, but they are also ap­pre­ci­ated for their skins.

• Positive Impacts
• food
• body parts are source of valuable material

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

None

Con­ser­va­tion Sta­tus

Lions and wild dogs prey on si­tatun­gas, and leop­ards catch some that ven­ture into river­ine for­est. Si­tatun­gas are vul­ner­a­ble to snare-trap­pers due to their use of reg­u­lar path­ways. They may also be dri­ven by beat­ers into nets or into deep water where spear­men in boats eas­ily dis­patch them. (Estes, 1991; Honacki et al., 1982)

• IUCN Red List

  Least Concern
  More information

• IUCN Red List

  Least Concern
  More information

• US Federal List

  No special status

• CITES

  Appendix III No special status

Other Com­ments

The si­tatunga and bush­buck are close enough ge­net­i­cally to pro­duce vi­able hy­brids in cap­tiv­ity, and al­most in­dis­tin­guish­able from the nyala ex­cept for pelage and hooves. (Estes, 1991)

Si­tatunga is a com­mon host an­i­mal for the par­a­site Schis­to­soma, a blood fluke found in mesen­tery blood ves­sels. (De­lany, 1979)

When being pur­sued, si­tatun­gas may avoid de­tec­tion by sub­merg­ing in swamps until only their nos­trils and eyes re­main above water. (Estes, 1991)

Con­trib­u­tors

Marcy Coash (au­thor), Uni­ver­sity of Michi­gan-Ann Arbor, Phil Myers (ed­i­tor), Mu­seum of Zo­ol­ogy, Uni­ver­sity of Michi­gan-Ann Arbor.

Ref­er­ences

De­lany, M. 1979. Ecol­ogy of African Mam­mals. New York, New York: Long­man group Inc..

Estes, R. 1991. The Be­hav­ior Guide to African Mam­mals. Berke­ley and Los An­ge­les, Ca.: Uni­ver­sity of Cal­i­for­nia Press.

Games, I. 1983. Ob­ser­va­tions on si­tatunga (Trage­la­phus spekii selousi) in the. Bi­o­log­i­cal Con­ser­va­tion, 27: 157-170.

Honacki, J., K. Kin­man, J. Koeppl. 1982. Mam­mal Species of the World. Lawrence, Kansas: Allen Press Inc., and The As­so­ci­a­tion of Sys­tem­at­ics Col­lec­tions.

King­don, J. 1974. East African Mam­mals. Chicago, Il.: The Uni­ver­sity of Chicago Press.

Nowak, R. 1991. Walker's Mam­mals of the World. Bal­ti­more, Md.: Johns Hop­kins Uni­ver­sity Press.

Starin, E. 2000. Notes on Si­tatunga in the Gam­bia. African Jour­nal of Ecol­ogy, 38: 339-342.