The gerenuk (; so, garanuug; ''Litocranius walleri''), also known as the giraffe gazelle, is a long-necked

antelope The term antelope is used to refer to many species of even-toed ruminant that are indigenous to various regions in Africa and Eurasia. Antelope comprise a wastebasket taxon defined as any of numerous Old World grazing and browsing hoofed mamm ...

found in parts of East Africa. The sole member of the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

''Litocranius'', the gerenuk was first described by the naturalist

Victor Brooke Sir Victor Alexander Brooke, 3rd Baronet (5 January 1843 – 23 November 1891), was an Anglo-Irish sportsman- naturalist and baronet. He was the father of Field Marshal The 1st Viscount Alanbrooke, and grandfather of The 1st Viscount Brookeboro ...

in 1879. It is characterised by its long, slender neck and limbs. The antelope is tall, and weighs between . Two types of colouration are clearly visible on the smooth

coat A coat typically is an outer garment for the upper body as worn by either gender for warmth or fashion. Coats typically have long sleeves and are open down the front and closing by means of buttons, zippers, hook-and-loop fasteners, toggles, ...

: the reddish brown back or the "saddle", and the lighter flanks, fawn to buff. The horns, present only on males, are lyre-shaped. Curving backward then slightly forward, these measure .

Taxonomy and phylogeny

The gerenuk was first described by

in 1879 on the basis of three male

specimen Specimen may refer to: Science and technology * Sample (material), a limited quantity of something which is intended to be similar to and represent a larger amount * Biological specimen or biospecimen, an organic specimen held by a biorepository f ...

s procured on "the mainland of Africa, north of the island of Zanzibar". Brooke used the

scientific name In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bo ...

''Gazella walleri'', on the request of Gerald Waller (who provided the specimens) to name it after his deceased brother. The type locality was later corrected by John Kirk, who originally obtained the specimens on the "coast near the River Juba in southern

Somalia Somalia, , Osmanya script: 𐒈𐒝𐒑𐒛𐒐𐒘𐒕𐒖; ar, الصومال, aṣ-Ṣūmāl officially the Federal Republic of SomaliaThe ''Federal Republic of Somalia'' is the country's name per Article 1 of thProvisional Constitut ...

" before giving them to Waller. In 1886, Franz Friedrich Kohl proposed a new genus for the gerenuk, ''Litocranius''. The common name derives from the

Somali Somali may refer to: Horn of Africa * Somalis, an inhabitant or ethnicity associated with Greater Somali Region ** Proto-Somali, the ancestors of modern Somalis ** Somali culture ** Somali cuisine ** Somali language, a Cushitic language ** Somali ...

name for the animal (''gáránúug''); the first recorded use of the name dates back to 1895. It is also known as the "giraffe gazelle" due to its similarity to the

giraffe The giraffe is a large African hoofed mammal belonging to the genus ''Giraffa''. It is the tallest living terrestrial animal and the largest ruminant on Earth. Traditionally, giraffes were thought to be one species, '' Giraffa camelopardal ...

. Two

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics ( morphology), but that can successfully interbreed. Not all specie ...

have been proposed, but these are considered to be independent species by some authors. * ''L. w. sclateri'' (Northern gerenuk or Sclater's gazelle)

Neumann Neumann is German and Yiddish for "new man", and one of the 20 most common German surnames. People * Von Neumann family, a Jewish Hungarian noble family A–G *Adam Neumann (born 1979), Israeli-born entrepreneur and founder of WeWork * Alfre ...

, 1899: Its range extends from northwestern Somalia (

Berbera District Berbera District ( so, Degmada Barbara) is a district of the Sahil province in Somaliland. Its capital lies at Berbera. Demographics It is inhabited by people from the CIISE MUUSE, Garhajis and Habr Je'lo sub-clans of the Isaaq Somalis Th ...

) westward to touch the Ethiopian border and Djibouti. * ''L. w. walleri'' (Southern gerenuk or Waller's gazelle) (Brooke, 1879): Its range extends through northeastern Tanzania through Kenya to Galcaio (Somalia). The range lies north of the

Shebelle River The Shebelle River ( so, Webi Shabeelle, ar, نهر شبيلي, am, እደላ) begins in the highlands of Ethiopia, and then flows southeast into Somalia towards Mogadishu. Near Mogadishu, it turns sharply southwest, where it follows the coast ...

and near Juba River. In 1997

Colin Groves Colin Peter Groves (24 June 1942 – 30 November 2017) was a British-Australian biologist and anthropologist. Groves was Professor of Biological Anthropology at the Australian National University in Canberra, Australia. Education Born in Englan ...

proposed that ''Litocranius'' is a sister

taxon In biology, a taxon ( back-formation from '' taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular n ...

of the similarly long-necked dibatag (''Ammodorcas clarkei''), but withdrew from this in 2000. A 1999

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups ...

study based on

cytochrome b Cytochrome b within both molecular and cell biology, is a protein found in the mitochondria of eukaryotic cells. It functions as part of the electron transport chain and is the main subunit of transmembrane cytochrome bc1 and b6f complexes. F ...

and

cytochrome c oxidase subunit III Cytochrome c oxidase subunit III (COX3) is an enzyme that in humans is encoded by the ''MT-CO3'' gene. It is one of main transmembrane subunits of cytochrome c oxidase. It is also one of the three mitochondrial DNA (mtDNA) encoded subunits (M ...

analysis showed that the

tribe The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide usage of the term in English is in the discipline of anthropology. This definition is contested, in part due to confl ...

Antilopini Antilopini is a tribe of bovids often referred as true antelopes like gazelles. They live in and around the Sahara, Horn of Africa, throughout eastern and southern Africa, and Eurasia. Depending on species, the females have either very short and/ ...

, to which the gerenuk belongs, is

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gr ...

. In 2013, Eva Verena Bärmann and colleagues (of the

University of Cambridge , mottoeng = Literal: From here, light and sacred draughts. Non literal: From this place, we gain enlightenment and precious knowledge. , established = , other_name = The Chancellor, Masters and Schola ...

) revised the phylogeny of tribe on the basis of

nuclear Nuclear may refer to: Physics Relating to the nucleus of the atom: *Nuclear engineering *Nuclear physics *Nuclear power *Nuclear reactor *Nuclear weapon *Nuclear medicine *Radiation therapy *Nuclear warfare Mathematics *Nuclear space *Nuclear ...

and

mitochondrial A mitochondrion (; ) is an organelle found in the cells of most Eukaryotes, such as animals, plants and fungi. Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is used t ...

gene analysis. The

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to ...

prepared by them (given below) showed that the

springbok The springbok (''Antidorcas marsupialis'') is a medium-sized antelope found mainly in south and southwest Africa. The sole member of the genus ''Antidorcas'', this bovid was first described by the German zoologist Eberhard August Wilhelm ...

(''Antidorcas marsupialis'') forms a

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English ter ...

with the gerenuk; this clade is sister to the

saiga The saiga antelope (, ''Saiga tatarica''), or saiga, is a critically endangered antelope which during antiquity inhabited a vast area of the Eurasian steppe spanning the foothills of the Carpathian Mountains in the northwest and Caucasus in t ...

(''Saiga tatarica'', tribe

Saigini Saigini is a tribe of artiodactyl mammals of the Bovidae family, subfamily Antilopinae, comprising two species of medium-sized antelopes that inhabit the Eurasian steppes. Taxonomy Description The tribe was created in 1945 by the American pa ...

) and the genera ''Antilope'' (

blackbuck The blackbuck (''Antilope cervicapra''), also known as the Indian antelope, is an antelope native to India and Nepal. It inhabits grassy plains and lightly forested areas with perennial water sources. It stands up to high at the shoulder. Ma ...

), ''

Eudorcas ''Eudorcas'' is a genus of antelope; the species are commonly called gazelles. ''Eudorcas'' was originally considered a subgenus of the genus ''Gazella A gazelle is one of many antelope species in the genus ''Gazella'' . This article also ...

'', ''

Gazella A gazelle is one of many antelope species in the genus ''Gazella'' . This article also deals with the seven species included in two further genera, '' Eudorcas'' and '' Nanger'', which were formerly considered subgenera of ''Gazella''. A third ...

'' and '' Nanger'' (of Antilopini).

Description

The gerenuk is a notably tall, slender

that resembles

gazelle A gazelle is one of many antelope species in the genus ''Gazella'' . This article also deals with the seven species included in two further genera, '' Eudorcas'' and '' Nanger'', which were formerly considered subgenera of ''Gazella''. A third ...

s. It is characterised by its long, slender neck and limbs, the flat, wedge-like head and the large, round eyes. Males are nearly tall, and the shorter females ; the head-and-body length is typically between . Males weigh between ; females are lighter, weighing . The species is

sexually dimorphic Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...

. The tail, that ends in a black tuft, measures . Two types of colouration are clearly visible on the smooth

: the reddish brown

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage * Dorsal c ...

parts (the back or the "saddle"), and the lighter flanks, fawn to buff. The underbelly and insides of the legs are cream in colour. The eyes and the mouth are surrounded by white fur. Females have a dark patch on the

crown A crown is a traditional form of head adornment, or hat, worn by monarchs as a symbol of their power and dignity. A crown is often, by extension, a symbol of the monarch's government or items endorsed by it. The word itself is used, partic ...

. The horns, present only on males, are lyre-like ("S"-shaped). Curving backward then slightly forward, these measure . The gerenuk resembles the dibatag, with which it is

sympatric In biology, two related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter one another. An initially interbreeding population that splits into two or more distinct species s ...

in eastern and central Somalia and southeastern Ethiopia. Both are brachyodonts and share several facial and

cranial Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...

features, along with a two-tone colouration of the coat and strong thick horns (only in males). However, there are also some features distinguishing it from the gerenuk, including major morphological differences in horns, horn cores, tail,

postorbital The ''postorbital'' is one of the bones in vertebrate skulls which forms a portion of the dermal skull roof and, sometimes, a ring about the orbit. Generally, it is located behind the postfrontal and posteriorly to the orbital fenestra. In some ...

area and

basioccipital The basilar part of the occipital bone (also basioccipital) extends forward and upward from the foramen magnum, and presents in front an area more or less quadrilateral in outline. In the young skull this area is rough and uneven, and is joined t ...

processes. The gerenuk has a longer, heavier neck and a shorter tail. A finer point of difference is the absence of an inward-curving lobe in the lower edge of the ear (near its tip) in the gerenuk. The subspecies of the gerenuk are similar in colouration; the southern gerenuk is the smaller of the two.

Ecology and behaviour

The gerenuk is a diurnal animal (active mainly during the day), though it typically stands or rests in shade during the noon. Foraging and feeding is the major activity throughout the day; females appear to spend longer time in feeding. The gerenuk may expose itself to rain, probably to cool its body. The social structure consists of small herds of two to six members. Herds typically comprise members of a single sex, though female herds additionally have juveniles. Some males lead a solitary life. Fighting and travel are uncommon, possibly as a strategy to save energy for foraging. Both sexes maintain

home range A home range is the area in which an animal lives and moves on a periodic basis. It is related to the concept of an animal's territory which is the area that is actively defended. The concept of a home range was introduced by W. H. Burt in 1943. He ...

s large, and might overlap. Those of males are scent-marked with

preorbital gland The preorbital gland is a paired exocrine gland found in many species of hoofed animals, which is homologous to the lacrimal gland found in humans. These glands are trenchlike slits of dark blue to black, nearly bare skin extending from the me ...

secretions and guarded - hence these may be termed

territories A territory is an area of land, sea, or space, particularly belonging or connected to a country, person, or animal. In international politics, a territory is usually either the total area from which a state may extract power resources or a ...

. The sedentary tendency of the antelope appears to increase with age.

Diet

Primarily a browser, the gerenuk feed on foliage of bushes as well as trees, shoots, herbs, flowers and fruits. It can reach higher branches and twigs better than other gazelles and antelopes by standing erect on its hindlegs and elongating its neck; this helps it reach over above the ground. ''

Acacia ''Acacia'', commonly known as the wattles or acacias, is a large genus of shrubs and trees in the subfamily Mimosoideae of the pea family Fabaceae. Initially, it comprised a group of plant species native to Africa and Australasia. The genus nam ...

'' species are eaten whenever available, while evergreen vegetation forms the diet during droughts. The pointed mouth assists in extracting leaves from thorny vegetation. The gerenuk does not drink water regularly. Major predators of the antelope include

African wild dog The African wild dog (''Lycaon pictus''), also called the painted dog or Cape hunting dog, is a wild canine which is a native species to sub-Saharan Africa. It is the largest wild canine in Africa, and the only extant member of the genus '' Lyca ...

cheetah The cheetah (''Acinonyx jubatus'') is a large cat native to Africa and central Iran. It is the fastest land animal, estimated to be capable of running at with the fastest reliably recorded speeds being , and as such has evolved specialized ...

hyena Hyenas, or hyaenas (from Ancient Greek , ), are feliform carnivoran mammals of the family Hyaenidae . With only four extant species (each in its own genus), it is the fifth-smallest family in the Carnivora and one of the smallest in the cl ...

lion The lion (''Panthera leo'') is a large cat of the genus '' Panthera'' native to Africa and India. It has a muscular, broad-chested body; short, rounded head; round ears; and a hairy tuft at the end of its tail. It is sexually dimorphic; adu ...

s and

leopard The leopard (''Panthera pardus'') is one of the five extant species in the genus '' Panthera'', a member of the cat family, Felidae. It occurs in a wide range in sub-Saharan Africa, in some parts of Western and Central Asia, Southern Russia, ...

Reproduction

Gerenuk reproduce throughout the year. Females reach

sexual maturity Sexual maturity is the capability of an organism to reproduce. In humans it might be considered synonymous with adulthood, but here puberty is the name for the process of biological sexual maturation, while adulthood is based on cultural definit ...

at around one year, and males reach sexual maturity at 1.5 years, although in the wild they may only be successful after acquiring a territory (perhaps 3.5 years). The

gestation period In mammals, pregnancy is the period of reproduction during which a female carries one or more live offspring from implantation in the uterus through gestation. It begins when a fertilized zygote implants in the female's uterus, and ends once ...

is about seven months. They are born one at a time, weighing about at birth. Offspring were produced through

artificial insemination Artificial insemination is the deliberate introduction of sperm into a female's cervix or uterine cavity for the purpose of achieving a pregnancy through in vivo fertilization by means other than sexual intercourse. It is a fertility treatment ...

for the first time in 2010 at

White Oak Conservation White Oak Conservation, which is part of Walter Conservation, is a conservation center in northeastern Florida. It has long been dedicated to the conservation and care of endangered and threatened species, including rhinoceros, okapi, bongo a ...

Yulee, Florida Yulee is a Census county division (CCD) in Nassau County, Florida, United States. The population is currently 28,798 as of April 2018. Yulee is part of the Jacksonville metropolitan area, which was home to 1,504,980 people in 2017. Today, t ...

. Four female calves were born, and one of the four was later inseminated successfully by White Oak and SEZARC (South-East Zoo Alliance for Reproduction & Conservation), creating a second generation of calves born from artificial insemination. Gerenuk can live thirteen years or more in captivity, and at least eight years in the wild.

References

External links

Gerenuk
at the ''

Encyclopædia Britannica The (Latin for "British Encyclopædia") is a general knowledge English-language encyclopaedia. It is published by Encyclopædia Britannica, Inc.; the company has existed since the 18th century, although it has changed ownership various t ...

''
Gerenuk at Al Wabra Wildlife Preserve
{{Taxonbar, from=Q208112 Antilopini Fauna of East Africa Fauna of the Horn of Africa Mammals described in 1879 Mammals of Djibouti Mammals of Ethiopia Mammals of Kenya Mammals of Somalia Mammals of Tanzania