Head and body length: 125-150 cm

Shoulder height: 81-90 cm

Tail length: 18-23 cm

Adult weight: 28.5-38.6 kg

A large, heavyset gazelle; males are larger than females and have particularly robust necks. The general body color is pale yellowish-brown and the undersides are strikingly white; the two colors meet in a sharp horizontal line across the flanks. A large white rump patch extends above the base of the tail and protrudes forward on each hip in a characteristic point. The tail itself is white with a black tuft of hair at the tip. The face is strikingly marked with bold stripes. The centre of the face, from the horns to the muzzle, is deep reddish-black, bordered by striking white stripes. Another black stripe on each side of the face runs from the horns, through the eye, to the muzzle. The chin and upper throat are white. Both sexes have distinctive question-mark-shaped horns with tips that curve inwards. Horns of males are heavy and deflect backwards from the forehead; the basal two thirds are heavily ringed with 14-22 annulations. Typical horn length for males is 38-48 cm, but exceptional specimens may exceed 58 cm. Horns of females are much thinner and less laterally curved, and are typically shorter (exceptionally they may exceed 40 cm).

Similar species

• Grant's gazelle (Nanger granti) also lives in East Africa, but has a more southerly range. Both species lack a dark flank strip (seen in most small gazelles), but can be easily differentiated by horn shape and the high contrast of the facial markings in Soemmerring's gazelle.

Gestation period: 6.5-7 months.

Litter size: One.

Weaning: Around 6 months.

Sexual maturity: Females at 18-21 months.

Life span: Up to 15.5 years.

In the wild, Soemmerring's gazelles breed year round; calves have been recorded in every month in Ethiopia, although they were observed in lower numbers between October and December. Infants weigh 3.5-4.5 kg at birth, and typically lie cached in dense vegetation for the first month.

Soemmerring's gazelles are adapted to arid savannas and can survive with low water consumption. In Sudan, seasonal migrations were formerly recorded: northward in March/April, and returning southward in September/October for the dry season. However, it is unknown whether these still occur due to the decline of available habitat and a decreasing number of gazelles. Typical current population density is 1.3-1.8 animals per km². Mature males are territorial, staking out areas of desireable resources - notably good forage - to attract females. Territories are marked with dung middens, and are defended from other males. Males herd groups of females as they wak through their territories, vocalizing with a "nasal croak" while doing so. The breeding behaviour of this species lacks the laufschlag foreleg kick typical of gazelles. Instead, the male drives the female at a walking pace, with a ritualized "trotting in place."

Family group: Females typically live in small herds of 3-5 individuals. In open habitats herds tend to be larger: 5-20 individuals are common, but they may number 50-150 or even 250 individuals. Mature males tend to be solitary, associating with females when they enter their territories. Young males may form small bachelor groups.

Diet: Primarily grasses and herbs.

Main Predators: Cheetah, African wild dog, lion, hyena. Young are susceptible to predation by smaller carnivores, including caracal, serval, jackals, birds of prey, and pythons.

Soemmerring's gazelles inhabit open grasslands interspersed with thorny brush in the Horn of Africa, to altitudes of 1,000 m. The approximate range is depicted in the map below; the three main regions of occupancy coincide with the three named subspecies: N. s. soemmerringii from Sudan, N. s. berberana from northern Ethiopia, Eritrea, and Somalia, and N. s. butteri from southern Ethiopia. The population on Eritrea's Dahlak Kebir Island is of unknown taxonomic status.

IUCN Red List: Vulnerable (2016).

CITES Listing: Not listed (2017).

Threats: Illegal hunting and habitat degradation, particularly overgrazing by livestock.

The total population is estimated to be 6,000-7,500 individuals, and continues to show declines across the species' mainland range. Approximately half of the world population - estimated at 3,000-4,000 animals - inhabits Dahlak Kebir Island (Eritrea), where the species was likely introduced historically.