Common duiker
The common duiker (Sylvicapra grimmia), also known as the gray duiker or bush duiker, is a small antelope and the sole member of its genus, widely distributed across sub-Saharan Africa from Senegal in the west to South Africa in the south.[1][2] Characterized by a shoulder height of 45–60 cm, body length of 80–115 cm, and weight of 10–20 kg, it has a grizzled gray to pale reddish-brown coat, whitish underparts, a short black crest between the ears, and a distinctive black tuft on its short tail; males possess straight, vertically oriented horns measuring 7–18 cm, while females are hornless or rarely have short spikes.[3][1] This adaptable species inhabits a variety of open to semi-closed environments, including savannas, grasslands, scrublands, woodlands, and mountainous areas up to 3,000 m elevation, but it generally avoids dense rainforests and arid deserts.[1][3] Primarily crepuscular or nocturnal, common duikers are often solitary or form monogamous pairs, maintaining territories marked by glandular secretions and dung piles; they exhibit agile, bounding locomotion and produce loud bleating alarm calls when threatened.[3][1] Their diet is mainly browsing-oriented, consisting of leaves, shoots, fruits, seeds, and flowers, supplemented opportunistically by insects, small vertebrates, birds, and even carrion; gestation lasts 4–7 months, typically yielding one (rarely two) precocial young per birth, with sexual maturity reached at 8–9 months.[1][3] Classified as Least Concern on the IUCN Red List due to its extensive range spanning 39 countries and a large, stable population estimated in the millions, the common duiker faces no major global threats but experiences localized declines from bushmeat hunting, habitat fragmentation, and human-wildlife conflict.[2][1][4]Taxonomy
Classification
The common duiker, known scientifically as Sylvicapra grimmia (Linnaeus, 1758), belongs to the order Artiodactyla, which encompasses even-toed ungulates, and is placed within the family Bovidae, a diverse group of ruminant artiodactyls including antelopes, cattle, and goats.[5] Within Bovidae, it is assigned to the subfamily Cephalophinae, which comprises the duikers—small to medium-sized antelopes adapted primarily to forested and wooded environments—though classifications vary at the subfamily level, with some phylogenetic analyses placing the duiker tribe Cephalophini within the broader subfamily Antilopinae.[6][2] The genus Sylvicapra is monotypic, containing only S. grimmia as its sole species, highlighting its unique taxonomic position among duikers. Evolutionarily, S. grimmia is part of the Cephalophinae subfamily, which originated in the late Miocene epoch approximately 6–8 million years ago, as evidenced by the earliest fossil records from African sites.[7] This divergence from other bovid lineages reflects an adaptation to Africa's diverse habitats, transitioning from ancestral forest-dwelling forms to more open savanna environments, with the subfamily's radiation driven by Pleistocene climatic fluctuations and habitat fragmentation.[7] Fossil evidence, including horn cores and postcranial remains, supports this timeline, positioning Cephalophinae as a relatively recent offshoot within the Bovidae family, which itself traces back to the early Miocene around 20 million years ago. Common names for S. grimmia include gray duiker, bush duiker, and savanna duiker, reflecting its widespread distribution and adaptability across sub-Saharan Africa.[2] The species encompasses several subspecies that vary slightly in morphology and geographic range, with further details provided in dedicated taxonomic discussions.[5]Subspecies
The common duiker (Sylvicapra grimmia) is classified into 11 recognized subspecies, reflecting adaptations to diverse habitats across sub-Saharan Africa, though some classifications propose up to 14 or more based on varying interpretations of morphological clines.[8] These subspecies exhibit regional variations in pelage coloration, body size, horn length, and coat texture, often correlated with local environmental conditions such as aridity or elevation.[8] Subspecies recognition relies primarily on morphological differences, including variations in fur color (from grayish-yellow to reddish or pale tones), pelage length (longer in montane forms), cranial measurements, ear size (larger in arid-adapted populations), and the extent of the black nasal blaze on the face.[8] However, boundaries between subspecies can be debated due to clinal variation, with intermediate forms common where ranges overlap, complicating strict delineations without genetic confirmation.[8] The following table summarizes the 11 recognized subspecies, their primary distributions, and notable variations:| Subspecies | Distribution | Key Variations |
|---|---|---|
| S. g. grimmia | Southern South Africa (Cape Province) | Type subspecies; typical grizzled gray pelage; moderate size and horn length. |
| S. g. altivallis | Central Kenya (Aberdare Mountains, Mt. Kenya) | Montane form with longer pelage; darker tones; extended nasal blaze. |
| S. g. caffra | Southern Mozambique, eastern Zimbabwe, Swaziland, Lesotho, northeastern South Africa | Lighter, grayish coat; brighter forehead; medium size adapted to savanna. |
| S. g. campbelliae | Eastern Guinea to western Uganda, Rwanda, Burundi | Smaller size; less pronounced hue differentiation; variable nasal blaze. |
| S. g. hindei | Southeastern Kenya, northern Tanzania | Small body and ears; long fur; varied hues; short legs. |
| S. g. lobeliarum | Eastern Uganda, western Kenya (Mt. Elgon) | Montane-adapted with elongated pelage; darker coloration. |
| S. g. madoqua | Western Ethiopia, western Eritrea | Pale tones suited to semi-arid conditions; larger ears. |
| S. g. nyansae | Southeastern Sudan to western Kenya | Intermediate size; grizzled pelage; adapted to woodland-savanna transitions. |
| S. g. orbicularis | Southern Somalia to northern Mozambique | Fading nasal blaze below eyes; glossy short pelage in lowlands. |
| S. g. splendidula | Southeastern Gabon to western Zimbabwe | Reddish hues in forested areas; whitish underparts; medium horn length. |
| S. g. steinhardti | Southern Angola to northwestern South Africa | Pale feet; larger body size; minimal caudal spotting; arid-adapted features. |