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.
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.
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).
- Habitat Regions
- tropical
- terrestrial
- Terrestrial Biomes
- forest
- rainforest
- Other Habitat Features
- agricultural
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.
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.
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.
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.
- Other Physical Features
- endothermic
- homoiothermic
- bilateral symmetry
- Sexual Dimorphism
- female larger
- ornamentation
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.
- Mating System
- monogamous
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.
- Key Reproductive Features
- iteroparous
- year-round breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- viviparous
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.
- Parental Investment
-
pre-fertilization
- provisioning
-
protecting
- female
-
pre-hatching/birth
-
provisioning
- female
-
protecting
- female
-
provisioning
-
pre-weaning/fledging
-
provisioning
- female
-
provisioning
- 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.
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).
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.
- Key Behaviors
- terricolous
- nocturnal
- motile
- sedentary
- solitary
- territorial
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.
- Other Communication Modes
- scent marks
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.
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.
- 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.
- 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.
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
Cephalophus 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
.
- 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.
- 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 (
Cephalophus monticola
), can conceal themselves in the more open habitats where they live.
Other Comments
Cephalophus silvicultor
is considered one of the most evolutionarily ancestral (primitive) African antelopes
that exists today.
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.
Additional Links
Contributors
Tanya Dewey (editor), Animal Diversity Web.
Kristina DeWitt (author), University of Wisconsin-Stevens Point, Chris Yahnke (editor, instructor), University of Wisconsin-Stevens Point.
- Ethiopian
-
living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- tropical
-
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
- terrestrial
-
Living on the ground.
- forest
-
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
- 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.
- agricultural
-
living in landscapes dominated by human agriculture.
- 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.
- 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.
- 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.
- monogamous
-
Having one mate at a time.
- 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).
- year-round breeding
-
breeding takes place throughout the year
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- viviparous
-
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
- nocturnal
-
active during the night
- motile
-
having the capacity to move from one place to another.
- sedentary
-
remains in the same area
- solitary
-
lives alone
- 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
- visual
-
uses sight to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
- scent marks
-
communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- 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.
- food
-
A substance that provides both nutrients and energy to a living thing.
- herbivore
-
An animal that eats mainly plants or parts of plants.
- frugivore
-
an animal that mainly eats fruit
References
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 .
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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 .
"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 Barnes and Noble Inc.