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Cephalophus silvicultoryellow-backed duiker

By Kristina DeWitt

Geographic Range

Cephalophus silvicultor is found throughout western central Africa. Yellow-backed duikers range from Guinea-Bissau eastward to Uganda and Sudan, and as far south as Angola and Zambia. Yellow-backed duikers have the widest range in comparison to other forest duiker species. They are typically found in forested areas with dense understory growth. ("The Encyclopedia of Mammals", 2001; Herman and Sayama, 1951; Huffman, 2004)

Habitat

Yellow-backed duikers prefer forested habitats with dense undergrowth, although they can be found in a variety of forested habitats, including savannah and farmland. There is evidence of interspecific competition between yellow-backed duikers and their larger relatives, Jentink's duikers (Cephalophus jentinki). In some situations, Jentink's duikers may force yellow-backed duikers out of preferred habitat. (Newing, 2001)

In captivity, yellow-backed duikers are not tolerant of cold temperatures. They cannot be exposed to climates of 7 degrees Celsius (55 degrees Fahrenheit) for a prolonged time, but can tolerate temperatures of 43 degrees Celsius (110 degrees Fahrenheit). (Barnes, et al., 2002)

Physical Description

The coat of yellow-backed duikers is black or brown in color with a yellow triangular patch near the tail. This yellow patch typically will not appear until about 1 month of age and will not be completely developed until about 10 months. Males and females resemble each other in appearance, although females are slightly larger. The muzzle area is a light gray color which surrounds their white lips. Both sexes have short, conical horns that grow between 8.5 and 21 centimeters long. ("The Encyclopedia of Mammals", 2001; Huffman, 2004)

Young yellow-backed duikers are born a dark brown color with spotted flanks and red undersides. These cryptic colors help them remain hidden from predators in the forest. ("The Encyclopedia of Mammals", 2001; Huffman, 2004)

Yellow-backed duikers have unique scent glands located posterior to each eye. Unlike other antelope species, these glands secrete from a grouping of pores, not from a solitary large opening. These scent glands are used to mark territorial boundaries. Yellow-backed duikers are built for life in dense vegetation. The body is arched, with short forelegs and longer hindlegs for manuverability. ("The Encyclopedia of Mammals", 2001; Huffman, 2004)

Yellow-backed duikers are one of the largest species of forest duikers, ranging from 45 to 80 kilograms in the wild. The body is 115 to 145 centimeters in length, with a short tail measuring 11 to 18 centimeters. Yellow-backed duikers have the largest brain size relative to body size than any other antelope species. ("The Encyclopedia of Mammals", 2001)

  • Range mass
    45 to 80 kg
    99.12 to 176.21 lb
  • Range length
    115 to 145 cm
    45.28 to 57.09 in

Reproduction

Yellow-backed duiker mating pairs have been observed licking and nibbling each other socially. This behavior is also viewed between mothers and calves. Adult duikers socially rub their preorbital scent glands on other adults bodies and legs. Duiker mates also press these scent glands together as a possible sign of pair bonding. It is thought that females defend territories that they share with males. However, the pair bond may be fairly transitory. (Estes, 1991)

In captivity, yellow-backed duikers go into estrus once per month throughout the year, lasting 2 to 3 days. Gestation is approximately 7 months, after which females give birth to one calf. Occasionaly, 2 calves are born. Females may breed twice each year. Young yellow-backed duikers stay hidden for 1 to 2 weeks in the forest. One male calf in captivity at the Los Angeles Zoo was weaned after 95 days, although others have been recorded at about 5 months. Females are sexually mature at 9 to 12 months of age, while males reach maturity at 12 to 18 months. (Barnes, et al., 2002; Huffman, 2004)

  • Breeding interval
    Yellow-backed duikers may breed twice each year.
  • Breeding season
    Yellow-backed duikers can breed throughout the year.
  • Range number of offspring
    1 to 2
  • Average number of offspring
    1
  • Average number of offspring
    1
    AnAge
  • Range gestation period
    4 (low) months
  • Average gestation period
    7 months
  • Range weaning age
    3.17 to 5 months
  • Range age at sexual or reproductive maturity (female)
    9 to 12 months
  • Range age at sexual or reproductive maturity (male)
    12 to 18 months

Young are weaned after approximately 5 months. It is unknown how long young stay with the mother. The young remain hidden for their first week of life, after which they begin to emerge from hiding to browse on vegetation. (Huffman, 2004)

  • Parental Investment
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
  • extended period of juvenile learning

Lifespan/Longevity

In captivity, other species of Cephalophus can live 10 to 15 years. In the wild duikers can live 10 to 12 years. ("The Encyclopedia of Mammals", 2001; Huffman, 2004)

  • Range lifespan
    Status: wild
    10 to 12 years
  • Average lifespan
    Status: captivity
    22.5 years
    AnAge

Behavior

Yellow-backed duikers are a non-gregarious species. They rest alone during the day in "forms" - regularly used resting places under fallen trees, in dense undergrowth, or in root forms - and forage at night. Males and females share territories and loosely associate for mating. Duikers are exceptionally susceptible to stress in captivity (capture myopathy). ("The Encyclopedia of Mammals", 2001; Barnes, et al., 2002; Kranz and Lumpkin, 1982)

Yellow-backed duikers have also been seen resting on the peaks of termite mounds in order to gain a vantage point. This and the fact that some females have been observed with broken horns, suggests that duikers actively defend territories. Territorial boundaries are also marked with the maxillary glands. (Huffman, 2004)

Home Range

Home range sizes are not known.

Communication and Perception

Yellow-backed duikers communicate with unique scent glands anterior to the eyes. These maxillary glands are made of connective tissues that surrounds 2 to 3 secretory layers forming hairless slits. The presence of these glands cause the cheeks to swell. Duikers also have scent glands behind each hoof. Gland scents are used to communicate territorial boundaries, reproductive status, and as a way of cementing social bonds. Yellow-backed duikers also communicate through grunts and shrill bleats. When alarmed, these duikers emit a shrill whistle, erect their dorsal crest, and flee. ("The Encyclopedia of Mammals", 2001; Estes, 1991; Huffman, 2004)

Food Habits

Yellow-backed duikers are selective-foraging frugivores. Typical diets are low in fiber. Starches are fermented quickly, with rapid passage through the digestive tract. Along with fruit, yellow-backed duikers eat leaves, seeds, buds, bark, and shoots. Four yellow-backed duikers in the wild ate 71.3% fruit matter and 28.6% dry weight. Occasionally, these forest antelopes will kill and eat small animals, such as birds. Of the 28.6% dry weight, 0.1% was animal matter. (Barnes, et al., 2002; Kranz and Lumpkin, 1982)

Yellow-backed duikers specialize on eating fallen fruits and can consume fruits or seeds that are too large or hard for primates and other frugivores to eat. Duiker cheek teeth are specialized for chewing tough bark and roots. A long pointed tongue and mobile lips allow foliage to be easily obtained and manipulated. Duikers search the ground for food using their hooves and snouts to dig. The large size of yellow-backed duikers forces them to forage almost constantly. (Estes, 1991)

  • Animal Foods
  • birds
  • mammals
  • Plant Foods
  • leaves
  • roots and tubers
  • wood, bark, or stems
  • seeds, grains, and nuts
  • fruit

Predation

Predators of yellow-back duikers include African hunting dogs, lions, and leopards. When they are alarmed, the typical resopnse is for the yellow rump hairs to stand erect. A shrill call may be emitted before dashing into the cover of underbrush habitat. Young duikers stay hidden in the forest for more than 7 days to evade predators before beginning to venture out. When threatened, the response is to flee into dense forest. Their habit of seeming to dive into the undergrowth gives them their common name, duiker, which is derived from Afrikaans for "diving buck." Yellow-backed duikers also hold their yellow rump hairs erect when agitated. (Huffman, 2004; Kranz and Lumpkin, 1982; Huffman, 2004; Kranz and Lumpkin, 1982)

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

It is unknown how important forest duikers are in seed dispersal in African forests. Duikers have been observed spitting out digested seeds after rumination. Some seeds remain intact and are dispersed in this way. Duikers act as predators on other seeds by damaging them during digestion. Larger mammals also prey on adult and young duikers. (Feer, 1995)

Three new species of Coccidia have been found in forest duikers. These parasites were not found in any other wild or domestic African ruminant. Coccidia was documented in Philantomba monticola, Cephalophus dorsalis, and Cephalophus nigrifrons. Cephalophus maxwelli was discovered with the parasite Selenomas ruminanticum. It is possible that Coccidia species will be discovered in C. silvicultor. (Herman and Sayama, 1951; Pampiglione, et al., 1973)

  • Ecosystem Impact
  • disperses seeds

Economic Importance for Humans: Positive

Cephalophus silvicultor is an important form of meat and money for people living in central and western Africa. In many instances, yellow-backed duiker meat is necessary bushmeat for local survival. They are hunted with a variety of methods, including snares, shotguns, or netting. At night, duikers are easily shot because they stand still when light is shone on them. (Newing, 2001)

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

Economic Importance for Humans: Negative

There are no known adverse effects of Cephalophus silvicultor on humans.

Conservation Status

Human expansion has caused a change in some African habitats from mature forests to clearings for agriculture, directly impacting yellow-duiler populations, which rely on forested habitat. Yellow-backed duikers require dense forest cover to hide, because of their large size. Smaller duikers, such as blue duikers (Philantomba monticola), can conceal themselves in the more open habitats where they live. (Estes, 1991; Wilkie and Finn, 1990)

Other Comments

Cephalophus silvicultor is considered one of the most evolutionarily ancestral (primitive) African antelopes that exists today. ("The Encyclopedia of Mammals", 2001)

The name "duiker" comes from an African word meaning "diver". This refers to their tendency to run and hide in forest cover when threatened. Cephalophus silvicultor can be broken into its Greek roots. "Kephale" refers to the head, and "lophus" to a crest, both are associated with a tuft of fur on the yellow-backed duikers head. "Silva" means woods or forest, and "cultor" implies a farmer or inhabitant, both these terms imply the animal lives in the forest. (Huffman, 2004)

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Kristina DeWitt (author), University of Wisconsin-Stevens Point, Chris Yahnke (editor, instructor), University of Wisconsin-Stevens Point.

Glossary

Ethiopian

living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

World Map

acoustic

uses sound to communicate

agricultural

living in landscapes dominated by human agriculture.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

cryptic

having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

food

A substance that provides both nutrients and energy to a living thing.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

frugivore

an animal that mainly eats fruit

herbivore

An animal that eats mainly plants or parts of plants.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

monogamous

Having one mate at a time.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

scent marks

communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

sexual ornamentation

one of the sexes (usually males) has special physical structures used in courting the other sex or fighting the same sex. For example: antlers, elongated tails, special spurs.

solitary

lives alone

tactile

uses touch to communicate

terrestrial

Living on the ground.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

year-round breeding

breeding takes place throughout the year

References

"San Francisco Zoo Animals" (On-line). Yellow-backed Duiker. Accessed October 13, 2006 at http://www.sfzoo.org/cgi-bin/animals.py?ID=87.

2001. The Encyclopedia of Mammals. Pp. "542-545" in D MacDonald, ed. Barnes and Noble Inc.

Barnes, R., K. Greene, J. Holland, M. Lamm. 2002. Management and Husbandry of Duikers at the Los Angeles Zoo. Zoo Biology, 21/2: "107-121".

Estes, R. 1991. The Behavior Guide to African Mammals Including Hoofed Mammals, Carnivores, Primates. University of California Press. Accessed November 29, 2006 at http://books.google.com/books?hl=en&lr=&id=g977LsZHpcsC&oi=fnd&pg=PR11&sig=73mHRqw7GQTw93UUcVXIIx7s6jM&dq=duiker+mating+systems&prev=http://scholar.google.com/scholar%3Fq%3Dduiker%2Bmating%2Bsystems%26hl%3Den%26lr%3D#PRA1-PA90000,M1.

Feer, F. 1995. Seed Dispersal in African Forest Ruminants. Journal of Tropical Ecology, 11: 687-689. Accessed December 01, 2006 at http://www.jstor.org/view/02664674/di008869/00p0125a/0?frame=frame&userID=8fec23ca@uwsp.edu/01cce4405f00501b3ca63&dpi=3&config=jstor.

Geser, S., P. Dollinger. 2006. "World Association of Zoos and Aquariums (WAZA)" (On-line). WAZA - World Association of Zoos and Aquariums - Virtual Zoo. Accessed October 13, 2006 at http://www.waza.org/virtualzoo/factsheet.php?id=119-009-009-014&view=Antelopes.

Herman, C., K. Sayama. 1951. Further Notes on Selenomonas from Californian Mammals. Transactions of the American Microscopical Society: 185-187. Accessed November 29, 2006 at http://www.jstor.org/view/00030023/sp050176/05x0019s/0?frame=noframe&userID=8fec23ca@uwsp.edu/01cc99331300501b33b1a&dpi=3&config=jstor.

Huffman, B. 2004. "An Ultimate Ungulate Fact Sheet" (On-line). Cephalophus silvicultor. Accessed October 13, 2006 at http://www.ultimateungulate.com/Artiodactyla/Cephalophus_silvicultor.htm.

Kranz, K., S. Lumpkin. 1982. Notes on the Yellow-backed duiker Cephalophus sylvicultor in captivity with comments on its natural history. International Zoo Yearbook, 22: 232-240.

Newing, H. 2001. Bushmeat Hunting and Management: implications of duiker ecology and interspecific competition. Biodiversity and Conservation, 10: "99-118".

Pampiglione, S., G. Ricci-Bitti, M. Kabala. 1973. On Some Coccidia of Cephalophus in Zaire. Journal of Wildlife Disease, 9: 282-286. Accessed November 29, 2006 at http://www.jwildlifedis.org/cgi/reprint/9/4/282.

Plowman, A. 2002. Nutrient Intake and Apparent Digestibility of Diets Consumed by Captive Duikers at the Dambari Field Station, Zimbabwe. Zoo Biology, 21: "135-147".

Wilkie, D., J. Finn. 1990. Slash-Burn Cultivation and Mammal Abundance in the Ituri Forest, Zaire. Biotropica, Vol. 22, No. 1: pp. 90-99. Accessed November 29, 2006 at http://links.jstor.org/sici?sici=0006-3606%28199003%2922%3A1%3C90%3ASCAMAI%3E2.0.CO%3B2-V&size=LARGE.

Woolf, N. 1986. New Hope for Exotic Species,. BioScience, Vol 36/No 9: 594-597. Accessed November 29, 2006 at http://www.jstor.org/view/00063568/ap040293/04a00040/0?frame=noframe&userID=8fec23ca@uwsp.edu/01cc99331300501b33b1a&dpi=3&config=jstor.

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