Duiker, rhymes with biker

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Of course - sorry - it was not a living thylacine, and I'm both impressed and dismayed that the real answer - Zebra duiker or Banded duiker Cephalophus zebra - had been posted within 20 minutes of publication [adjacent photo of C. zebra from the Zebra duiker page on the outstanding Ultimate Ungulate]. Well done Chris (of Catalogue of Organisms) for getting there so quick. I saw the Zebra duiker photo (taken at Sapo National Park in Liberia by a team gathering data on pygmy hippos), on the EDGE blog (here) and thought it would be fun to use for this purpose. And of course now I have a good excuse to talk (briefly) about duikers...

Duikers, or cephalophines, are an entirely African group of bovids, and so far as we know they have never gotten out of Africa. Virtually nothing is known of their early history: there's a partial maxilla and a molar from the Miocene, and a few Pliocene and Pleistocene records, some of which are of extant species. The Miocene molar is interesting as it's from northern Africa, where no duikers occur today. However, Manlius (2001) suggested that an animal depicted in a 4th dynasty hunting scene (dating to c. 2561-2459 BC) at Atet's tomb in Meidum, Egypt, is a Jentink's duiker C. jentinki, and proposed on the basis of this that an isolated population of this species might have persisted in Egypt until at least this time. Flores (2001) pointed out that duiker bones were identified from an Egyptian tomb in 1948, perhaps providing support for this idea. Given the present range of C. jentinki (Sierra Leone, Liberia, Ivory Coast), a purported presence in ancient Egypt is very difficult to believe, but maybe these discoveries do show that duikers did occur north of the Sahara until recently.

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Phylogenetic work suggests that duikers belong to four distinct lineages. Maxwell's duiker C. maxwelli and the Blue duiker C. monticola - together sometimes called the blue duikers or the 'conservative dwarfs' - seem to form a clade that is the sister-group to all other duikers. They differ from the others in lacking inguinal glands, in having an untufted tail and in other features. On the basis of these differences the blue duikers have sometimes been given their own genus, Philantomba, and the distinct status and monophyly of this taxon was recently supported by Jansen van Vuuren & Robinson (2001). A widespread and very successful savannah specialist (the Bush duiker, Grey duiker, Common duiker or Grimm's duiker Sylvicapra grimmia: over 40 subspecies have been named) forms the sister-taxon to a combined giant duiker and red duiker clade (Jansen van Vuuren & Robinson 2001). The phylogenetic position of the Zebra duiker and Ader's duiker C. adersi are uncertain and they may represent distinct lineages within the giant duiker + red duiker clade [adjacent image shows the duiker case at the Walter Rothschild Museum in Tring. From The Art of Jane Tomlinson].

Containing about 20 species and a substantially greater number of subspecies, the duiker radiation appears to have occurred rapidly and recently (post-Miocene), with the amount of divergence between the major lineages being relatively minor. The exact placement of duikers within Bovidae is uncertain but they're almost certainly antilopines close to gazelles, dwarf antelopes and so on (Hassanin & Douzery 1999a, b, Price et al. 2005). Their small size and 'slinker' ecomorphotype (read on) have generally led to the assumption that duikers are primitive. However, their complex brains, reduced horns, and shortened faces led Kingdon (1997) to suggest that they're dwarfed from larger ancestors rather than primitive, and the genetic and fossil data do suggest that they're a young group.

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Ranging in size from about 4 to about 80 kg, duikers include diurnal, cathemeral and nocturnal species (cathemeral animals are active at any hour). Mostly forest dwellers, they also include savannah species as well as taxa that frequent montane environments (Ruwenzori duiker C. rubidus) and swamps (Black-fronted duiker C. nigrifrons). Some species have been reported to climb on sloping tree trunks. Most species are coloured in reds and browns but some are blackish. Jentink's duiker, the largest species, has a black head and neck, a white collar over the shoulders, and a grizzled grey body (despite its size and striking appearance, it wasn't scientifically discovered until 1884 and not named until 1892) [adjacent photo of Jentink's duiker from here on Ultimate Ungulate]. Reddish crests that virtually conceal the small, posteriorly placed horns are common. Apparently, duiker's hearts are huge, being about twice as large, proportionally, as that of a human (Ralls 1973).

Duikers are what is known as slinkers: mostly small-bodied, they rely on concealment and rapid acts of explosive saltation to avoid and escape predators, they are highly territorial, monogamous, and with sexes that (generally) are similarly sized* and similarly armed (slinking has also been termed the 'microcursorial adaptive syndrome', but that ain't so catchy). The ability of duikers to dive rapidly into deep cover explains their common name (it's Afrikaans for diver). It's apparently pronounced like 'biker', and not 'doy-kah' as I've been saying for the last few decades. Duikers possess large preorbital (or maxillary) glands as well as pedal glands and (in some) inguinal (= groin) glands, and they frequently mark objects in their territory, in some cases doing so about every 10 minutes.

* Female duikers are often up to 4% bigger than males.

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Like all slinkers, duikers specialise on high quality food like leaves and fruits, and fungi and bark are also eaten. They also eat insects and carrion, and regularly kill and eat frogs, small mammals, lizards, and birds. That's right: omnivorous bovids. Ants were found to make up over 10% of the stomach contents (dry weight) of Blue duiker (Ronald & Kranz 2001) and captive animals are fed dog food in addition to plants (Nowak 1999). Some duiker species have been reported to sometimes toy with prey in the same way that domestic cats do. In Angola, people believe that the Yellow-backed duiker C. sylvicultor eats the meat of Bell's hinge-backed tortoise Kinixys belliana by forcibly blasting the tortoise's body out of the shell (Lumpkin & Kranz 1984). I don't think this is true but wish it was [the picture shown above - from here on Ultimate Ungulate - shows an Abbott's duiker C. spadix photographed in the Udzungwa Mountains, Tanzania. One of the first photos ever taken of this species in the wild, it shows the duiker eating a frog].

While duikers might seem like the sort of mammals that would usually be regarded as 'less advanced' than the big, noble antelopes that live out on the sunny plains (and, indeed, some workers have interpreted things this way), there are indications from duiker anatomy and behaviour that they are actually among the smartest and most complex of bovids: if you like, the 'most advanced'. Their brains are large and complex and are said to be the biggest (proportionally) of all the bovids. A relatively long gestation and slow growth rate may be consequences of a prolonged learning period (Kingdon 1997), and it seems that duikers have to learn to predict and exploit the behaviour of herbivorous canopy animals, like monkeys, fruit bats and birds. The fruits that these animals drop are eaten by the duikers.

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Spinage (1986) wrote about a Common duiker that he raised as a pet and later released into the wild. It then disappeared completely, until (two months later) a grass fire destroyed all the vegetation that the duiker would have been familiar with. The duiker now reappeared, standing in the open behind the house where it had been reared, looking dejected. In a charred and blackened environment, Spinage suggested that the duiker had returned to the only familiar place. He petted it, and it went away, but when seen again on later occasions it would run up to him and stand to be stroked (Spinage 1986, p. 134) [adjacent image shows skull of Maxwell's duiker. Image © University of Edinburgh, from here].

Evidence suggests that duikers are being harvested at unsustainable rates for the bushmeat trade, and most species are now regarded as being at risk.

For previous Tet Zoo articles on bovids see McGowan's mystery bovid, Welcome.... to the world of sheep, Return.... to the world of sheep, and the brief article on takins.

Refs - -

Flores, D. V. 2001. More about duikers in ancient Egypt. Science 292, 440.

Hassanin, A. & Douzery, J. P. 1999a. Evolutionary affinities of the enigmatic saola (Pseudoryx nghetinhensis) in the context of the molecular phylogeny of Bovidae. Proceedings of the Royal Society of London B 266, 893-900.

- . & Douzery, J. P. 1999b. The tribal radiation of the family Bovidae (Artiodactyla) and the evolution of the mitochondrial cytochrome b gene. Molecular Phylogenetics and Evolution 13, 227-243.

Jansen van Vuuren, B. & Robinson, T. J. 2001. Retrieval of four adaptive lineages in duiker antelope: evidence from mitochondrial DNA sequences and fluorescence in situ hybridization. Molecular Phylogenetics and Evolution 20, 409-425.

Kingdon, J. 1997. The Kingdon Field Guide to African Mammals. Academic Press, San Diego.

Lumpkin, S. & Kranz, K. R. 1984. Cephalophus sylvicultor. Mammalian Species 225, 1-7.

Manlius, N. 2001. Were there duikers in ancient Egypt? Science 291, 1701.

Nowak, R. M. 1999. Walker's Mammals of the World, Sixth Edition. Volume II. The Johns Hopkins University Press, Baltimore and London.

Price, S. A., Bininda-Emonds, O. R. P. & Gittleman, J. L. 2005. A complete phylogeny of the whales, dolphins and even-toed hoofed mammals (Cetartiodactyla). Biological Reviews 80, 445-473.

Ralls, K. 1973. Cephalophus maxwelli. Mammalian Species 31, 1-4.

Ronald. K. & Kranz, K. 2001. Duikers. In MacDonald, D. (ed) The New Encyclopedia of Mammals. Oxford University Press (Oxford), pp. 542-545.

Spinage, C. A. 1986. The Natural History of Antelopes. Christopher Helm, London.

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What became of those Egyptian bones, as couldn't they be identified further to see if they are indeed Jentink's duiker, or some other species that occurs closer to Egypt?

By Richard Hing (not verified) on 08 Aug 2008 #permalink

Nice! BTW, somebody posted a similar cropped picture of Jentink's duiker shoulders on a related forum. Everybody answered "ratel" or "malayan tapir".

Duiker... hmmm... how shall I remember that? when I used to go to school, they didn't tell us about it, and I have finished my education thinking that I know almost everything :) ehe :) nobody told me, that discovering new species is constant process - I think that's not Ok.
I discovered this blog lately - and i find it very interesting.
Greetings,

Lovely article about lovely animals! They remind me of a reconstruction of early domestic cows which looked quite tiny and duikery... grrr... can't remember in which book I saw that (last century).
As to the pronunciation... the few people I heard talk about them seem to say 'diker'. But from an Afrikaans (or Dutch) standpoint 'doyker' is just as good an approximation, as is 'dowker'.

As Afrikaans speaker, it would more closely rhyme with "Faker", and that with a slightly rolled "r". The UI sound in Afrikaans is almost a tripthong, moving from the throat to the middle of the mouth.

They are cute animals and even survive quite close to urban areas. I see then quite often on my way to work in the midlands of Natal, Cedara, some 25km west of Pietermaritzburg.

Great to know more about them.

The problem is that in most areas they just call it "Meat".

Their German name is "Ducker" - in other words, an animal that ducks (for cover). Is this is a corruption of the Afrikaans name 'Duiker', or an actual description of the animal's behaviour?

I always assumed it was pronounced 'Dooker'. Don't I feel linguistically advanced.

Wonderful article.... Now when are you gonna show us the REAL thylacine photos, huh?

By Max Paddington (not verified) on 08 Aug 2008 #permalink

I can all tell you, being a Dutch speaker myself, that the -ui-sound is one that simply does not exist in English, nor is there anything really close to it. By the way, us Dutch speakers use the same sound for the letter combinations -uy-and occasionaly eu-. (It's an ' ui' in 'euforie' or 'Euhelopus'...but not in ' Europa'. There it is yet another sound that is nonexistent in English) I'm sorry I can't make things easier!

Very nice article. Always thought about duikers as a primitive clad. Now you opened my eyes, I ought to read about them more as behaviour of clewer animals is always so interesting.
The scull is also speaks for itself.

BTW, what are English rules of names adopted from other languages?

So, duiker is da-ook-err. Why, then, jacana is not pronounced yassana?

On the pronounciation:

I lived in the Netherlands for awhile and from the little dutch I learned I thought it was pronounced "Dowker".
It is spelled like the dutch word for sugar, suiker, pronounced like "sowker", I think.
Brian above would know better then I.

I will now have to pronounce it so that english speakers know what I am talking about. I was getting odd looks saying "dowker". hmm. :)

Ok now people, back to important matters :-)
glands... horns... jaws...
Catching and eating meat without upper incisors seems hard. Makes one wonder if they swallow those frogs whole or chew them up first.

This seems to be as good a place/time as any to ask a question that I have oft' pondered: Do any ungulates without upper incisors bite defensively? My little experience with hoofed beasts is with horses and cattle. Horses of course will bite quite nastily, but cattle never seem to. They just dip and lift their head to engage their horn with you if they have a problem with you. Even when restrained cattle only use their horns and feet. So duikers eat some meat huh? Fascinating and cool. Do they bite when caught? Do any other bovids or antilocaprids etc. sans uppers bite when caught? ...always wondered...

Manlius (2001) suggested that an animal depicted in a 4th dynasty hunting scene (dating to c. 2561-2459 BC) at Atet's tomb in Meidum, Egypt, is a Jentink's duiker C. jentinki, and proposed on the basis of this that an isolated population of this species might have persisted in Egypt until at least this time. Flores (2001) pointed out that duiker bones were identified from an Egyptian tomb in 1948, perhaps providing support for this idea. Given the present range of C. jentinki (Sierra Leone, Liberia, Ivory Coast), a purported presence in ancient Egypt is very difficult to believe, but maybe these discoveries do show that duikers did occur north of the Sahara until recently.

Natural ranges are surely not sacrosanct where humans are involved. Is it too hard to believe that, if duikers made good hunting (whatever that is conceived as, culturally) - and also made good eating? decorative pelts? - then they might have been reported, sought, captured, transported, bred and released, deliberately introduced into Egypt to provide both entertainment and a delicacy for Egyptian nobility?

Apes and peacocks were reportedly brought to Solomon, and did not Montezuma have a zoo and aviary of exotic species? I seem to recall... also hearing of other zoologic/botanic gardens in antiquity... eg Hanging Gardens of Babylon...
Wallabies, coypu, exotic felids... in UK... all outside their 'natural range'... and doing fine it seems!

By Graham King (not verified) on 08 Aug 2008 #permalink

Many thanks to all for comments. Some select responses. Richard asked...

What became of those Egyptian bones, as couldn't they be identified further to see if they are indeed Jentink's duiker, or some other species that occurs closer to Egypt?

Good question. Flores (2001) cited Brunton (1948) as regards the finding of duiker skull and leg bones 'in a predynastic grave at Matmar (in the Badari region) dated to the Naqada III period'. She didn't provide further information and you'd need to get hold of Brunton (1948) to see if the identification could be taken further. It may well be worth tracking down those bones: they should be in London.

Jerzy asked: BTW, what are English rules of names adopted from other languages? That's a very good question. I don't think there are any rules (I certainly don't apply any): we just best guess words based on what they look like. Sorry.

Tilsim asked how duikers manage to eat meat given that they lack upper incisors. Duikers have a wide gape and flexible mouth, and after grabbing prey with the front of the mouth, they chew the prey into bits with the cheek teeth. They've been reported using their cheek teeth to break apart animals as big as pigeons. It would be useful to know if there are any characters of the dentition that correlate with these forays into carnivory, but so far as I can tell there aren't any detailed studies on duiker dentition.

AnJaCo asked if any ungulates without upper incisors bite defensively. Chevrotains are reported to bite in defence, but then they have big upper canines. Other than that, I'm not aware of defensive biting in ruminants, though I wouldn't rule it out. One of the Monty Python movies opens with some quote about moose bites being nasty.. but I don't think this was based on zoologically accurate data :) Having allowed goats and cows and so on to chew on my fingers (I have photos) I'm not really sure that any ruminant could give a painful bite with the front of its mouth.

Refs - -

Brunton, G. 1948. Matmar, British Museum Expeditions to Middle Egypt, 1929-1931. Quaritch, London.

Heh I just saw these being captured and eaten on Iplayer - was an episode of wild- unexplorered africa in central african rainforest. Ive always found these 'primitive' creatures interesting - nice article

This is essentially a zero-content post, but I find it somewhat amusing that this is now the top ranked google result for "omnivorous bovid."

After this post and thread I'm wondering; a few million years down the road might be see a beaked mammal evolving? that is, a horny covering over the premaxillae and the front of the dentary appearing to take the place of lost teeth.

Darren, you're too good for the internet! That was an exquisitely structured essay that belongs in something like "Harpers": the low-key natural history gradually building to a "human interest" peak with the comments on intelligence and the story of the tamed duiker... and then the shocking jab of the penultimate sentence, about the bushmeat trade.

This deserves wider circulation.

By Allen Hazen (not verified) on 08 Aug 2008 #permalink

Jerzy asked "what are English rules of names adopted from other languages?"

English, rules? You are kidding I assume. ;) As a lifelong English speaker I have long come to the conclusion that English doesn't have rules, just a set of rough guidelines that work more often (slightly more often) than not.

For what it's worth I have always pronounced the 'ui' in duiker as a diphthong, with a result something like duykuh - I have absolutely no reason to think this is anymore right than anyother suggestion, but it works for me.

With regard to pronunciation, what really winds me up is pronounciation of Greek/Latin binomials. I had several years compulsory Latin at school, and have done a little Greek (ancient, not modern), and I have quite strong feelings about things like C and G being pronounced hard etc. The rules I learned were that it is always correct to pronounce a scientific name using classical pronunciation, except where the name is derived from a proper noun in some other language, in which case it should be pronounced as in that language, but if in doubt classical Latin pronunciation should be used. The alternative, with c pronounced s and G pronounced j, is 'florists latin' - I guess that shows that much of my learning of the rules was way back in my 'A' level botany classes.

As far as I am concerned how people pronounce them is entirely up to them (as long as we all know what we are talking about) - but when books or on-line guides state how a name should be pronounced and don't follow proper Latin or Greek pronounciation that really annoys me.

Damn, I've gone off on one... ah well I guess most of you will disagree with me, but that just makes it more fun.

By the way Darren, may I agree with those who suggested it was truely evil of you to have very briefly raised a tiny hint of hope that the picture was of a thylacine. :)

By Mark Lees (not verified) on 08 Aug 2008 #permalink

Australia might not be the place to find the Thylacine.

Villagers in Indonesia Irian Jaya province claim to have found a Tasmanian tiger living in the hills around the Indonesian - Papua New Guinea border, the Antara News Agency reported in 1997. (http://www.petermaas.nl/extinct/speciesinfo/tasmaniantiger.html)

Does anyone know if this search continues?

Thanks for info!

About duikers in Egypt - it would be good to re-check these supposed duiker bones for mistake, I seen enough misidentifications repeated for decades. In any case, I agree that savanna-living gray duiker Sylvicapra is the only one likely to be known to ancient Egyptians.

About painting - some African pygmy goats are black-and-white - could it be one? Anybody knows the link to actual painting? Egyptian drawings generally distort shape.

(random brownian connection - one Egyptian artpiece shows elephant with long tusks but much smaller than humans. It was interpreted as dwarf Siberian mammoth, but may be more realistic proof of dwarf mediterranean elephant.)

Thanks Darren. I suppose one doesn't need carnassials to crush a frog or a pigeon... even us omnivorous hominids could do it with our unimpressive teeth if we ever wanted to.

I'm glad I'm not the only one who used to pronounce it "dooker". That pronunciation made me embarrassed as a kid because where I lived the word "dook" or "dookie" also meant excrement.

Response to Jerzy: I haven't seen the painting in question (it wasn't figured by the authors who've discussed it). Manlius says that the animal's head 'strongly resembles that of a duiker' and has short, simple horns not longer than the ears. He goes on to say that it has 'a dark brown head and neck with a belly, mane, and top length of the tail that are slate grey', and off-white ear insides, and white along the middle of the muzzle. While this colour scheme recalls that of Jentink's duiker, the mention of a mane is suspicious, as is the lack of a collar and the white muzzle stripe. Therefore, the apparent presence of Egyptian duiker bones may well be nothing at all to do with this painting.

The Egyptian 'dwarf mammoth' is well known (see Rosen 1994) and I often discuss it in lectures. The same painting also pictures what appears to be a dwarf bear. But then, there are enough strange animals in Egyptian artwork to warrant an entire blog post: serpopard, seth, bennu bird... Maybe I should work on that.

Refs - -

Rosen, B. 1994. Mammoths in ancient Egypt? Nature 369, 364.

As another South African I'm going to confirm what BadeMart said about the pronunciation of "duiker".

Rhyming it with "baker" will get you close enough that only a pedant would complain.

Thanks Darren,

Would be interesting! Actualy, early historic wildlife in the Meds region is fascinating - lots of animals had dramaticaly bigger ranges, and some wild animals were introduced already in ancient times. Bennu bird I guess was goliath heron or some conglomerate of wading birds. Sirruh was, of course, Cryolophosaurus. ;-)

Except for the horns and hooves, I think of duikers as being analogs of wynyardiid marsupials, the smallish primitive vombatomorphians that filled the small terrestrial browser niches in Australia's late Oligocene. They're usually reconstructed as more possum-like, but this reminds me to have a look at the limb bones (not something I deal with much).

By John Scanlon FCD (not verified) on 10 Aug 2008 #permalink

I find it extremely fascinating how the small, solitary 'slinker' type has evolved repeatedly in the ruminants in various parts of the world:

Tropical South and Central America: Mazama (Cervidae)

Andes: Pudu (Cervidae)

Central and West Africa: Hyemoschus (Tragulidae), Philantomba, Cephalophus, Sylvicapra, Neotragus (Bovidae)

Temperate East Asia: Moschus (Moschidae), Muntiacus, Elaphodus (Cervidae)

Tropical South and South-east Asia: Moschiola, Tragulus (Tragulidae), Muntiacus (Cervidae)

Many much larger forest-dwelling species have also essentially adopted a similar lifestyle, such as Okapia (Giraffidae), Tragelaphus (Bovidae) in Africa, Hyelaphus (Cervidae), Bubalus, Pseudoryx and Tetracerus (Bovidae) in tropical Asia.

Darren, is that Whitechalpel "boy-keh" or American "bye-kur"? I always took the pronounciation as a Dutch derivative, which would roll the first syllable a little, if I remember correctly.

By Jaime A. Headden (not verified) on 10 Aug 2008 #permalink

Neil: sad news, but note that this is a local extinction (as lars also occur in SE Asia, Thailand, Sumatra etc.), not a total extinction.

Thanks, PaulM! That's exactly what we needed.

I'm fascinated with vowel sounds that don't exist in English -- there are so many. (By contrast, idioms that can't be mapped to something already in English are astonishingly rare.) We USers have amazing difficulty just with Canadian "house".

If we start with a "long A" sound, in what direction do we modify it? Is there an extra bit at the beginning, or at the end? Which way is your tongue moving during the vowel? Would it be possible for you to post an audio file with you saying the word ten times, slowly?

By Nathan Myers (not verified) on 11 Aug 2008 #permalink

Nathan,

this Bert & Ernie video in Dutch might be helpful to you. Bert is outside. The Dutch word for outside, 'buiten', uses the -ui- sound that I referred to earlier. I don't have sound on this computer so I hope this is useful to you, despite me not having been able to listen to it first.

http://www.youtube.com/watch?v=nsEx4KKEvlk

Possibly the smartest of the bovids? I never knew that about duikers -- it's increased my respect for them. ;-) Anyway, thank you for this one.

A bovid playing with prey like a cat . . . that's disturbing on some level I can't explain.

By Maureen Lycaon (not verified) on 12 Aug 2008 #permalink

I have always had an interest in Forest african antelopes, the Duikers and felt that more work needs to be done as to how mant species exist, it has to be more than 20? any one have any ideas?

By Bob Michaels (not verified) on 22 Dec 2010 #permalink

Wow this is neat. Who would have thought that among the tiny ungulates of the world it's the duikers and not the befanged muntjacs that are carnivorous