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The stink badgers, genus Mydaus
The genus Mydaus was first described by F. G. Cuvier in 1821 [w5-14]. He gave the 'type species' of this genus, the Indonesian stink badger (or télagon, a name used on Java and borrowed by Cuvier [p1597]), the scientific name Mydaus meliceps. However, this species had already been described in 1820 by Desmarest, who had placed it in same genus as the skunks and named it Mephitis javanensis. It was accepted that the stink badgers should be placed in Cuvier's genus, Mydaus. However, as Desmarest had described the type species before Cuvier, the specific name javanensis took priority over meliceps and the species is referred to as Mydaus javanensis (Desmarest 1820).
The only other species in this genus, the Palawan stink badger Mydaus marchei, was first described by Huet in 1887 (see below). In 1939, Lawrence proposed that the Palawan stink badger should be placed in its own genus, Suillotaxus (giving it the scientific name Suillotaxus marchei) on the basis of differences in the teeth and markings of this species and Mydaus javanensis [w5-14]. Others however have rejected this proposal, arguing that the differences highlighted by Lawrence are minor and do not support the separation of these species into two genera; evidence of similarities in the teeth of the two species, and shared characteristics of their skulls and brains, is also cited [p36, p646]. For these reasons it is generally accepted that the Palawan stink badger should remain in the genus Mydaus. However it has also been proposed by some that the differences between Mydaus marchei and M. javanensis are sufficient to justify the unusual step of placing the former species in a subgenus, Suillotaxus [p36].
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The Indonesian stink badger, Mydaus javanensis
As noted above, this species was first described by Desmarest in 1820 as Mephitis javanensis, but it was later accepted as a member of a separate genus and re-named Mydaus javanensis. The type locality (the place where Desmarest had found the specimen used for his description of the species) was given as "l'île de Java" (the island of Java, Indonesia). [p111-3, w5-4]
A number of other naturalists have named populations of the Indonesian stink badger as separate species, but these are all regarded as synonyms (alternative names for the same species). Those synonyms include:
- Mydaus meliceps Cuvier, 1821. Type locality "Sumatra and Java". Re-named as described above, this is now regarded as the nominate subspecies Mydaus javanensis javanensis (see below). [p111-3, w5-4]
- Mydaus lucifer Thomas, 1902. Type locality “mainland near Labuan, Borneo”. Now recognised as the subspecies Mydaus javanensis lucifer Thomas, 1902 (see below). The holotype is held by the British Museum (Natural History), NHM Register number: 1876.9.20.10. [p111-3, w5-4, w1346-27]
- Mydaus ollula Thomas, 1902. Type locality "Sinubing and Mt. Ranai from Great Natuna Island," Indonesia. Now recognised as the subspecies Mydaus javanensis ollula Thomas, 1902 (see below). The holotype is held by the British Museum (Natural History), NHM Register number: 1895.11.8.10. [p111-3, w1346-28]
- Mydaus montanus Moulton, 1921. Type locality "Mt. Murud, Sarawak". Now recognised as the subspecies Mydaus javanensis lucifer Thomas, 1902 (see below). The holotype is held by the British Museum (Natural History), NHM Register number: 1921.9.2.1. [p111-3, w1346-26]
- Mydaus luciferoides Lönnberg and Mjöberg, 1925: 509. Type locality "open forest country round Pah Trap and Mein in the Kalabit country" Borneo. Now recognised as the subspecies Mydaus javanensis lucifer Thomas, 1902 (see below). [p111-3, w5-4]
Three subspecies of the Indonesian stink badger are currently recognised [p111-3]:
- Mydaus javanensis javanensis (Desmarest, 1820). The nominate subspecies. Synonym: meliceps Cuvier. Occupies the Indonesian islands of Java and Sumatra.
- Mydaus javanensis lucifer Thomas, 1902. Synonyms: luciferoides Lönnberg and Mjöberg, montanus Moulton. Found on the island of Borneo (Indonesia and Malaysia). This subspecies is said to be darker than M. j. javanensis, being black more often than brown [p36].
- Mydaus javanensis ollula Thomas, 1902. Occurs on Natuna Besar or Bunguran (North Natuna islands, Indonesia). Some include the stink badgers from this island within the subspecies M. j. javanensis [p36].
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The Palawan stink badger, Mydaus marchei
First described by Huet in 1887, who gave the type locality as "l'île Palaouan" (Palawan, Philippines) [p111-5, w5-5, w386]. Synonyms include:
- Mydaus schadenbergii Jentink, 1895. Type locality "Calamianes-Islands" (Calamian Islands, Philippines). [p111-5]
- Suillotaxus marchei Lawrence, 1939. [p111-5]
Although Lawrence's name for the Palawan stink badger in generally regarded as a synonym, with Suillotaxus accepted by some as a subgeneric name (see above), a number of publications refer to this species as Suillotaxus marchei rather than Mydaus marchei [p1, p3-1].
No subspecies of the Palwan stink badger are currently recognised. The stink badgers on the Calamian Islands are said to have bolder markings than those on the Palawan mainland [p36], but the differences between the populations are not significant and do not support the recognition of subspecies.
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Classification - stink badgers as badgers
Although the first stink badger to be scientifically described was placed with the skunks in the genus Mephitis (see above), the stink badgers were later classified as badgers in the subfamily Melinae on the basis of morphological evidence [p111-3], and that is where they remained for many years in most of the standard works on mammalian classification. Like the other mammals bearing the badger name, stink badgers are fossorial, which means they are adapted for a digging way of life. They have long claws on their well-developed forelegs which are used to dig for food and to excavate dens for shelter and for rearing their young. In a scientific paper published in 1999, a wide range of data used to classify the species within the order Carnivora was combined and used to generate a 'family tree' which showed the stink badgers to be closely related to the Eurasian and hog badgers (Meles meles and Arctonyx collaris), within the subfamily Melinae [p158].
The 'traditional' classification of the stink badgers is therefore as follows:
Kingdom: Animalia Linnaeus, 1758 - animals
Phylum: Chordata Balfour, 1880 - chordates
Subphylum: Vertebrata Cuvier, 1812 - vertebrates
Class: Mammalia Linnaeus, 1758 - mammals
Subclass: Theria Parker and Haswell, 1897
Infraclass: Eutheria Gill, 1872
Order: Carnivora Bowditch, 1821 - carnivores
Suborder: Caniformia Kretzoi, 1943
Infraorder: Arctoidea Flower, 1869
Family: Mustelidae Fischer, 1817 - mustelids
Subfamily: Melinae Bonaparte, 1838 - badgers
Genus: Mydaus Cuvier, 1821 - stink badgers
Species: Mydaus javanensis (Desmarest, 1820) - Indonesian stink badger
Species: Mydaus marchei Huet, 1887 - Palawan stink badger
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Classification - stink badgers as skunks
The classification of stink badgers within the subfamily Melinae, as show above, has not been universally accepted. A number of zoologists have suggested that stink badgers are more closely related to skunks than they are to badgers, and there is now a strong body of evidence to support this view.
Anal gland secretions
One of the more obvious features which the stink badgers have in common with skunks is their ability to squirt a directed stream of anal gland secretion in fluid form. While the other badger species are all capable of emitting strong-smelling anal gland secretions, none of them can 'spray' their secretions in the way that stink badgers and skunks can. As long ago as 1861 it had been noted that the anal gland secretion of the Indonesian stink badger has "the same smell as that of the American skunk" [p1459]. 35 years later in 1896 it was reported by one scientist that the main "odiferous material" in the anal gland secretion of the skunk is n-butyl mercaptan, and another scientist found that the very same substance occurs in the secretion of the Palawan stink badger [p1091].
Threat behaviour
It is interesting to note the similarities in the threat behaviour of the skunks and one of the stink badgers, exhibited by these animals before the use of their anal gland secretions. When Jerry Dragoo caught up with a hog-nosed skunk which he intended to capture, the animal threw its tail up and, while facing its pursuer, "stomped its front feet on the ground (a common threat behaviour exhibited by skunks)" [p259]. Compare this with the warning behaviour of the Palawan stink badger: "When approached, M. marchei foot stomps by raising each front foot [about] 5 cm off the ground and bringing each down with an audible sound" [p111-5].
Brain structure (neuroanatomy)
A scientific paper published in 1973 [p646] noted that the brains of stink badgers and skunks share several primitive features not found in the brains of badgers or other mustelids (relatively high rhinal fissure, short sylvian sulcus, poor development of postsylvian and postlateral sulci, and relatively large olfactory bulbs). The author of the paper was careful to point out that these features alone carry little weight when assessing the relationship between stink badgers and skunks, but stated that when taken together with other evidence they support the suggestion that these two groups of mammals are closely related.
Skulls and teeth
There are similarities in the teeth (or dentition) and the anatomy of the middle ear of stink badgers and skunks [p646]. Regarding dentition, there is no generation of milk teeth in the development of the teeth of stink badgers and skunks and it is suggested that this provides a "forcible argument" for classifying the stink badgers with the skunks [p1455].
DNA
Recent analyses of mitochondrial-DNA from 26 species of Carnivora [p652] and of a sequence of 6243 base pairs from six genes in 76 species of Carnivora [p560] both placed stink badgers with skunks.
Past distribution
An argument which has been put forward against the proposal that stink badgers and skunks are related, is the geographic separation of the two groups: the stink badgers occur in south-east Asia (along with other badger species), while skunks are found only in North and South America [p157]. However, fossil skunks from the Miocene and Pliocene have been found in Eurasia [p259, p646, p1463], including Miomephitis, Proputorius and Promephitis [p1465]. The available evidence indicates that the skunks originated in Eurasia and later spread to North America, with all the skunk species of the Americas originating from a single immigration event [p1108]. The Eurasian skunks later died out, with the exception of the stink badgers of south-east Asia which survive as relicts of this formerly more widespread group [p1455]. Unfortunately there is a large gap in the fossil record of the skunks [p1462], and no fossils of stink badgers pre-dating the modern-day species are known [p111-03, p111-05, p1587]. Perhaps in time fossils of skunks and stink badgers will be found which will bridge the gap between the ancient and modern forms and provide more clues about the evolution of these smelly yet fascinating creatures.
It appears that most zoologists and taxonomists now accept that stink badgers are skunks rather than badgers. This gives rise to the following classification of the stink badgers (from Order level):
Order: Carnivora Bowditch, 1821 - carnivores
Suborder: Caniformia Kretzoi, 1943
Infraorder: Arctoidea Flower, 1869
Family: Mustelidae Fischer, 1817 - mustelids
Subfamily: Mephitinae Gill, 1872 - skunks
Genus: Mydaus Cuvier, 1821 - stink badgers
Species: Mydaus javanensis (Desmarest, 1820) - Indonesian stink badger
Species: Mydaus marchei Huet, 1887 - Palawan stink badger
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Classification - stink badgers and skunks as non-mustelids
The placement of stink badgers with the skunks is only the beginning of the changes that have been proposed regarding the classification of these mammals. Much of the evidence which has pointed to the close relationship between stink badgers and skunks has also indicated that they should not be regarded as a part of the Mustelidae family.
In the 1973 paper referred to above [p646] it was pointed out that the brains of most of the earliest known mustelids from 20 to 25 million years ago were more advanced than those of modern stink badgers or skunks. The author suggested that this was evidence of an early time of divergence for these animals from the mustelids.
Most analyses of DNA meanwhile have provided evidence to show that the skunks diverged from the line leading to the procyonid (racoon) and true mustelid (badger, marten, weasel and otter) families before those families diverged from each other [p259, p479, p560, p1462, p1521]. A 'total evidence' (or 'combined evidence') analysis using data from both DNA and morphological features (skull and tooth characteristics) has produced the same outcome [p1516]. Some DNA analyses have generated slightly different results, with one recent study based on mitochondrial-DNA (specifically, cytochrome b) data showing the skunks and procyonids as sister-groups which split away from the line leading to the mustelids before diverging from each other [p1530]. Despite the difference in the detail this still places the skunks apart from the mustelids.
Analysis of chromosomes has also indicated that skunks are very different from mustelids, while research into serum proteins suggests that the weasels, otters, badgers and other true mustelids shared a common ancestor long after the skunks diverged from the group [p259, p652, p1458].
All of this evidence has led to the proposal that the skunks (including the stink badgers) should be classified not as a subfamily within the Mustelidae, but as a family in their own right, the Mephitidae [p652]. This changes the classification of the stink badgers (from Order level) as follows:
Order: Carnivora Bowditch, 1821 - carnivores
Suborder: Caniformia Kretzoi, 1943
Infraorder: Arctoidea Flower, 1869
Family: Mephitidae Bonaparte, 1845 - skunks
Genus: Mydaus Cuvier, 1821 - stink badgers
Species: Mydaus javanensis (Desmarest, 1820) - Indonesian stink badger
Species: Mydaus marchei Huet, 1887 - Palawan stink badger
There is now widespread support for this proposed classification, with the current edition of Mammal Species of the World listing the skunks and stink badgers as members of the Mephitidae family [p1578]. Agreement is not universal however. Morphological evidence from both living and fossil skunks, along with genetic evidence from protein electrophoresis, provides evidence suggesting that the skunks fall within rather than outwith the Mustelidae. On this basis it was suggested in 2004 that placing the skunks in their own family is premature and that they should remain within the Mustelidae pending further evidence [p479].
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Picture credits
The Palawan stink badger photo used at the head of this Article is © Peter Widmann, and used with his permission. Credits for the photos used in the right-hand margin of this page for site navigation can be found on the Credits page.
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