Ader's Duiker
Encyclopedia
The Aders' Duiker also known as Nunga in Swahili
, Kunga marara in Kipokomo, and Harake in Giriama
), is a small forest dwelling Duiker
found only on Zanzibar
and in a small coastal enclave
in Kenya
. It is also critically endangered. It is believed by some to be a subspecies of the Red, Harvey's
, or Peters's Duiker
or a subspecies of a combination of the above.
12 kilograms, while those in the south weigh only 7.5 kilograms. Aders' Duikers have a reddish-brown coat which is grayer on the neck and lighter down the backside and underneath. There is a small red crest running along the head. Aders' Duikers also have small, simple horns of 3 to 6 centimeters. The muzzle is pointed, and the nose has a flat front. The ears measure 7-8.3 cm long, and there is a marked cowlick or whorl of hair on the nape of the neck.
vegetation, especially on "red soil". C. adersi is sympatric with C. harveyi on the mainland and with C. monticola sundevalli on Zanzibar, although nothing is known regarding their ecological separation.
There are estimated to be around 1,400 Aders' Duikers left in the world. They are threatened by habitat destruction, feral dogs and over-hunting. Aders' Duikers are particularly sought by humans due to their soft skin and sweet meat.
Aders' Duikers live in coastal forest
s, thicket
s and woodland
s where they eat flower
s, leaves
, and fruit
which has fallen from the forest canopy. The species appears to be diurnal, as it is rarely seen active at night. Typical feeding patterns are from dawn to around 1100 hours, which is followed by a period of rest and rumination. At about 1500 hours Aders' Duikers generally become active, and will continue foraging until nightfall.
They are generally solitary or found in small groups, such as pairs or trios. They feed primarily on fallen flowers, fruits, and leaves - often picking up scraps dropped by monkeys and birds foraging in the trees. (Swai 1983; Imani pers. comm. to Williams 1998)
C. adersi shows a particular dependence on the flowers and berries which grow prolifically from trees common to the area, such as ebony (Diospyros consolataei), kudu berry (Cassine aethiopica) and bush guarri (Euclea schimperi), and bushes such as turkey berry (Canthium spp.) and Polyspheria. In addition to these, they will eat sprouts, buds, and other fresh growth found at ground level. This Duiker species can apparently manage without drinking, getting most of the hydration they need from their diet.
According to Williams et al. (1996), the Duikers have extremely specific habitat requirements, being found only in areas of old growth thicket, with the highest population densities (11.4±5.18 per km²) recorded in relatively undisturbed high thicket. However, Kanga (1999) did report some Aders' Duikers in secondary thicket. In the Arabuko-Sokoke Forest in Kenya, Aders' Duikers inhabit regions of Cyanometra forest.
Not much is known of the Aders' reproductive habits although it is speculated that they breed all year long. The population in Zanzibar
had declined from 5000 in 1983 to 640 in 1999, and it is thought it will probably continue to decrease rapidly. In Kenya
the Duiker is present at very low densities, though the decline is probably not as severe as the other population..
Several conservation plans have been made, and a captive-breeding program has been proposed.
Swahili language
Swahili or Kiswahili is a Bantu language spoken by various ethnic groups that inhabit several large stretches of the Mozambique Channel coastline from northern Kenya to northern Mozambique, including the Comoro Islands. It is also spoken by ethnic minority groups in Somalia...
, Kunga marara in Kipokomo, and Harake in Giriama
Giriama
The Giriama are one of the nine ethnic groups that make up the Mijikenda ....
), is a small forest dwelling Duiker
Duiker
A duiker is any of about 21 small to medium-sized antelope species from the subfamily Cephalophinae native to Sub-Saharan Africa.Duikers are shy and elusive creatures with a fondness for dense cover; most are forest dwellers and even the species living in more open areas are quick to disappear...
found only on Zanzibar
Zanzibar
Zanzibar ,Persian: زنگبار, from suffix bār: "coast" and Zangi: "bruin" ; is a semi-autonomous part of Tanzania, in East Africa. It comprises the Zanzibar Archipelago in the Indian Ocean, off the coast of the mainland, and consists of numerous small islands and two large ones: Unguja , and Pemba...
and in a small coastal enclave
Arabuko Sokoke National Park
The Arabuko-Sokoke Forest is located on the coast of Kenya, 110 km north of Mombassa and is protected as a national Forest Reserve. The Arabuko-Sokoke National Park is only a small portion of the Arabuko-Sokoke Forest Reserve, a few square kilometres in size and is located on the north-western...
in Kenya
Kenya
Kenya , officially known as the Republic of Kenya, is a country in East Africa that lies on the equator, with the Indian Ocean to its south-east...
. It is also critically endangered. It is believed by some to be a subspecies of the Red, Harvey's
Harvey's Duiker
Harvey's Red Duiker is one of 19 species of duiker found in Tanzania and scattered through Kenya, southern Somalia, and, possibly, central Ethiopia....
, or Peters's Duiker
Peters's Duiker
Peter's Duiker , is a small antelope found in Gabon, Equatorial Guinea, southern Cameroon and northern Republic of Congo....
or a subspecies of a combination of the above.
Characteristics
The Aders' Duiker stands at around 30 centimeters tall at the shoulder. Their weight varies greatly depending on geographical location; those in eastern Zanzibar weighWeight
In science and engineering, the weight of an object is the force on the object due to gravity. Its magnitude , often denoted by an italic letter W, is the product of the mass m of the object and the magnitude of the local gravitational acceleration g; thus:...
12 kilograms, while those in the south weigh only 7.5 kilograms. Aders' Duikers have a reddish-brown coat which is grayer on the neck and lighter down the backside and underneath. There is a small red crest running along the head. Aders' Duikers also have small, simple horns of 3 to 6 centimeters. The muzzle is pointed, and the nose has a flat front. The ears measure 7-8.3 cm long, and there is a marked cowlick or whorl of hair on the nape of the neck.
Distribution and habitat
Aders' Duikers live primarily in coastal forests and woodlands in Africa. The species can live in quite dry scrub near the sea or among coral outcrops - in Zanzibar they are restricted to tall thicket forest growing on waterless coral rag . In Arabuko Sokoke (Kenya), Aders' Duikers are most often trapped within CynometraCynometra
Cynometra is genus of tropical forest trees with a pantropical distribution. It is particularly important as a forest component in west Africa and the neotropics. Cynometra alexandri is a familiar timber tree of central and east Africa...
vegetation, especially on "red soil". C. adersi is sympatric with C. harveyi on the mainland and with C. monticola sundevalli on Zanzibar, although nothing is known regarding their ecological separation.
There are estimated to be around 1,400 Aders' Duikers left in the world. They are threatened by habitat destruction, feral dogs and over-hunting. Aders' Duikers are particularly sought by humans due to their soft skin and sweet meat.
Ecology and behavior
The species is very shy, alert, and sensitive to sound. As a result, common methods of hunting include the brute-force method of driving the Duikers into nets with dogs, or silent ambush at feeding sites.Aders' Duikers live in coastal forest
Forest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...
s, thicket
Thicket
A thicket is a very dense stand of trees or tall shrubs, often dominated by only one or a few species, to the exclusion of all others. They may be formed by species that shed large amounts of highly viable seeds that are able to germinate in the shelter of the maternal plants.In some conditions the...
s and woodland
Woodland
Ecologically, a woodland is a low-density forest forming open habitats with plenty of sunlight and limited shade. Woodlands may support an understory of shrubs and herbaceous plants including grasses. Woodland may form a transition to shrubland under drier conditions or during early stages of...
s where they eat flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s, leaves
Leaves
-History:Vocalist Arnar Gudjonsson was formerly the guitarist with Mower, and he was joined by Hallur Hallsson , Arnar Ólafsson , Bjarni Grímsson , and Andri Ásgrímsson . Late in 2001 they played with Emiliana Torrini and drew early praise from the New York Times...
, and fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
which has fallen from the forest canopy. The species appears to be diurnal, as it is rarely seen active at night. Typical feeding patterns are from dawn to around 1100 hours, which is followed by a period of rest and rumination. At about 1500 hours Aders' Duikers generally become active, and will continue foraging until nightfall.
They are generally solitary or found in small groups, such as pairs or trios. They feed primarily on fallen flowers, fruits, and leaves - often picking up scraps dropped by monkeys and birds foraging in the trees. (Swai 1983; Imani pers. comm. to Williams 1998)
C. adersi shows a particular dependence on the flowers and berries which grow prolifically from trees common to the area, such as ebony (Diospyros consolataei), kudu berry (Cassine aethiopica) and bush guarri (Euclea schimperi), and bushes such as turkey berry (Canthium spp.) and Polyspheria. In addition to these, they will eat sprouts, buds, and other fresh growth found at ground level. This Duiker species can apparently manage without drinking, getting most of the hydration they need from their diet.
According to Williams et al. (1996), the Duikers have extremely specific habitat requirements, being found only in areas of old growth thicket, with the highest population densities (11.4±5.18 per km²) recorded in relatively undisturbed high thicket. However, Kanga (1999) did report some Aders' Duikers in secondary thicket. In the Arabuko-Sokoke Forest in Kenya, Aders' Duikers inhabit regions of Cyanometra forest.
Not much is known of the Aders' reproductive habits although it is speculated that they breed all year long. The population in Zanzibar
Zanzibar
Zanzibar ,Persian: زنگبار, from suffix bār: "coast" and Zangi: "bruin" ; is a semi-autonomous part of Tanzania, in East Africa. It comprises the Zanzibar Archipelago in the Indian Ocean, off the coast of the mainland, and consists of numerous small islands and two large ones: Unguja , and Pemba...
had declined from 5000 in 1983 to 640 in 1999, and it is thought it will probably continue to decrease rapidly. In Kenya
Kenya
Kenya , officially known as the Republic of Kenya, is a country in East Africa that lies on the equator, with the Indian Ocean to its south-east...
the Duiker is present at very low densities, though the decline is probably not as severe as the other population..
Several conservation plans have been made, and a captive-breeding program has been proposed.
External links
- Aders’ duiker (Cephalophus adersi) at ARKive
- Aders’ duiker (Cephalophus adersi) at ultimateungulate