The Saharan striped polecat (Poecilictis libyca), also known as the Saharan striped weasel and Libyan striped weasel, is a species of mammal native to northern Africa. It belongs in the family Mustelidae, and debate exists among experts over what genus it belongs to; though formerly placed in Ictonyx along with the striped polecat, it is now placed in the lone member of a separate genus called Poecilictis. Genetic analysis has shown that its closest living relatives are the striped polecat and African striped weasel. It mainly inhabits dry, steppe-like environments with sparse bush cover along the edges of the Sahara desert and on its mountains, avoiding the most arid regions in its center. Occasionally, it is found in oases, woodlands and cultivated land. As a secretive animal, it has likely been overlooked in parts of its range, and sightings of it are still made in recent years in locations where it has not been recorded before.
Measuring in length excluding the tail, this species is a small, slender animal with short legs and a bushy tail. It tends to have a black face, underside and legs, with white facial patterns, a light-coloured back and flanks, and dark stripes running down its back. However, the exact colouration and patterning is highly variable between different individuals, and multiple subspecies have been established based on these differences. Fur length is also variable, with the light fur in some populations growing so long that it partly obscures the back stripes, making them appear to have spots or patches. Unlike its closest relatives, the Saharan striped polecat has fur on the undersides of its paws, likely as an adaptation to its sandy habitat. It has glands near its anus which can spray a noxious fluid at potential predators so that the animal can defend itself. Its striking colouration is an example of aposematism, warning predators of its spray to deter them from attacking. It is also highly aggressive to species it views as threats, including humans, commonly hissing and spitting at them rather than fleeing immediately. Sometimes, it will also feign death to avoid predation.
This animal is a capable digger, using its claws to excavate burrows for shelter. It is nocturnal and retreats into these burrows during the day, though it also inhabits crevices in rocks or burrows made by other animals. By night, it hunts for the small animals which it kills with a bite to the back of the skull. It mainly preys on lizards, but will also take insects, birds, eggs and small mammals. Captive individuals are also known to eat small amounts of plant matter. Because of its aggressive defensive behaviour and spray, most predators likely avoid preying on it, with the Pharaoh eagle-owl hunting it the most regularly. It may also compete with other mustelids such as the striped polecat and least weasel. A solitary animal, the Saharan striped polecat tends to live alone in the wild, but captive individuals can reportedly be kept together without fighting. The mating season is likely variable, and females give birth in a burrow to a litter of two to six young after a gestation period of 37 days to 11 weeks. Though categorized as a least-concern species by the IUCN, little research has been done on its population. Considering the pressure it faces from the loss and modification of its habitat, human–wildlife conflict, harvest for traditional medicine, and feral dogs, this species may actually be threatened.
Taxonomy and evolution
The Saharan striped polecat was scientifically named in 1833, when German biologists Wilhelm Hemprich and Christian Gottfried Ehrenberg reported that a species of mammal similar to the striped polecat (but differing in its patterning and smaller size) had been discovered in Libya. At the time, the striped polecat was assigned to the genus Mustela, so they assigned this new species to the same genus under the name Mustela libyca, with the specific name referencing its country of origin. A separate genus named Ictonyx was later established in 1835, originally containing only the striped polecat. The Saharan striped polecat would later be moved into this genus as well, being referred to as Ictonyx libyca for years, but a paper published in 2013 pointed out that because the generic name Ictonyx is masculine, the specific name should be spelled as libycus instead when this species is treated as a member of Ictonyx.
The genus placement of the Saharan striped weasel has been a matter of debate among experts. The assignment of this species to Ictonyx was first contested in 1920, when British zoologists Oldfield Thomas and Martin Hinton concluded that it is sufficiently distinct from the striped polecat to warrant placing it in a separate genus. They therefore erected the genus Poecilictis, of which the Saharan striped weasel became the type species, being renamed as Poecilictis libyca. The name of this genus combines the Ancient Greek words "" (, meaning "vari-colored" or "pied") and "" (, meaning "weasel"), in reference to the animal's black and white patterning.
Many later authors would accept the usage of this genus, with American paleontologist George Gaylord Simpson using it in a book published in 1945, in addition to British naturalists John Ellerman and Terence Morrison-Scott using it in a checklist of mammals published in 1951. On the contrary, French zoologist Pierre Louis Dekeyser and German zoologist Jochen Niethammer rejected the usage of Poecilictis in their studies published in 1950 and 1987 respectively, referring to the Saharan striped polecat as an Ictonyx species, and this classification was followed in the third edition of Mammal Species of the World published in 2005. With the advancement of genetic analysis, molecular studies conducted in the 21st Century have found that assigning the Saharan striped polecat and the striped polecat as the two only species of Ictonyx would make this genus paraphyletic. This can be resolved by either adding the African striped weasel into Ictonyx (as proposed in a 2008 study) or separating the Saharan striped weasel into Poecilictis (as supported by a study published in 2012). ASM followed the latter and moved this species to the genus Poecilictis.
Subspecies Several forms of the Saharan striped polecat were originally named as separate species, but are now thought to actually represent a single, highly variable species. Some of these former species are now considered subspecies of the Saharan striped polecat, while others are considered as junior synonyms of these subspecies. The following four subspecies were recognized in the third edition of Mammal Species of the World published in 2005:
SubspeciesTrinomial authorityDescriptionRangeSynonymsI. l. libyca (Nominate subspecies)Hemprich and Ehrenberg, 1833Smaller subspecies with irregular and indistinct patterning, and a black tail tip.Egypt and Libyaalexandrae Setzer, 1959I. l. multivittataWagner, 1841Variable in size, with more distinct patterns than the nominate subspecies. Tail tip may be black or white.Morocco, Algeria, Tunisia, Western Sahara, central Sudan and possibly east Chadfrenata Sundevall, 1842 vaillanti (Loche, 1856)I. l. oralisThomas and Hinton, 1920Larger than the nominate subspecies, with similarly indistinct patterning and black tail tip.Coastal areas of SudanI. l. rothschildiThomas and Hinton, 1920Small subspecies with thin fur, distinct patterning and a black tail tip. Skull more robust than that of I. l. multivittata.Southwestern areas of the Sahara Desert and northern Nigeria
Evolution
The Saharan striped polecat belongs to the Mustelidae, and more specifically to a subfamily Ictonychinae. Members of this subfamily are split into two tribes known as Ictonychini and Lyncodontini. This species is a member of the former tribe, which also includes the striped polecat, African striped weasel and marbled polecat. Results of genetic analyses indicate that the closest living relatives of the Saharan striped polecat are the striped polecat and African striped weasel. These two species form a clade which is the sister group to the lineage whose only living species is the Saharan striped polecat. A study published in 2008 suggested that the lineages of these two groups diverged between 3.5 and 3 million years ago, and hypothesized that an increase in aridity was the reason it occurred. However, a 2012 study proposed an earlier date between 4.8 and 4.5 million years ago for this divergence. The following cladogram shows the position of the Saharan striped polecat among its closest living relatives
Fossilized remains of Saharan striped polecats have been discovered in Pliocene and Pleistocene-aged deposits in northern Africa. The first to be discovered originate from Ahl al Oughlam, a site in Morocco preserving fossils that date back between 2.8 and 2.4 million years ago. This age range spans from the Piacenzian stage of the Late Pliocene across the Pliocene-Pleistocene boundary into the Gelasian stage of the Early Pleistocene. In 1997, some fossils closely resembling bones of modern Saharan striped polecats were reported from this site, being distinguished just by their smaller size. A prehistoric subspecies named Poecilictis libyca minor was therefore established based on these specimens. At the site of Tighennif, Algeria, some fossilized teeth and jaw fragments comparable to those of the Saharan striped polecat have been discovered. These have been labelled as Poecilictis cf. libyca since although they likely represent the modern species, the material is too fragmentary for conclusive identification. The exact age of the Tighennif deposits is not known, but they are believed to have formed about 1 million years ago during the Calabrian stage of the Pleistocene epoch.
Characteristics
The Saharan striped polecat is a small mammal, growing about in head-body length and in weight. Although there is no significant variation in body length between the two sexes, males tend to weigh more than females, in addition to having larger front paws and longer canine teeth. This species has a slender body with short legs, and its long tail adds an additional to its overall length. lts fur is erectile, fluffing out when the animal is excited, which makes it look larger when it does so. The fur consists of two main types of hair, namely a short, dense underfur and long, stout guard hairs. Hair length varies greatly between the different subspecies, and those with longer hair have a shaggy appearance. The guard hairs on the tail are notably long, making the tail appear bushy. Like some other mustelids, this species has glands near its anus which spray a noxious fluid when it feels threatened. The head of a Saharan striped polecat bears a short snout and small ears. The paws are rather narrow in form and most of the digits are spaced widely apart, though the third and fourth digits of each hind paw are closer together. Each paw has five digits and each digit bears a claw, with the front claws being longer than the hind claws. Although its two closest living relatives (the striped polecat and African striped weasel) have paws with mostly hairless undersides, those of the Saharan striped polecat differ in having thick hair on their soles. This believed to be an adaptation for the animal's sandy habitat, as are the smaller paw pads. Females bear two pairs of nipples, both of which are classified as inguinal (groin region) nipples.