Herpestidae  

Mongooses (family Herpestidae) are relatively small mammals (around 35 to 150 cm in length, 0.2 to 5 kg) with long faces and bodies, short legs, small rounded years, and generally long tapered bushy tails. They are found widely in the Old World tropics throughout Africa and Asia, as well as in the Middle East and southern Europe. They occur in diverse habitats including both open areas (such as deserts, savannas, and grasslands) and closed forests, from lowlands into montane regions above 2000 m.  Mongooses are essentially terrestrial, although some may occasionally climb trees or swim.  

Gilchrist et al. (2009) recognized 34 species of mongooses, which they placed in 15 genera, although they noted that further taxonomic research may change the number of species recognized (see Gilchrist et al. for examples of possible changes) as well as modify generic assignments (see Patou et al. 2009 and references therein). Twenty-five species are found in Africa and nine in Asia. Like a number of other hard-to-place mammals, the mongooses were at one time included in the family Viverridae. Based on a range of evidence, however, they are now placed in their own family, Herpestidae. Herpestidae formerly also included the Malagasy "mongooses" (which were placed in the subfamily Galidiinae), but recent molecular studies have indicated that all the extant Malagasy carnivores form a monophyletic group that is the sister group to the extant mongooses and this group is now treated as a distinct family, the Eupleridae; the clade composed of (Eupleridae + Herpestidae) is, in turn, sister to the Hyaenidae (Agnarsson et al. 2010; Eizirik et al. 2010).

Within the Herpestidae, two subfamilies are now recognized based on morphological, molecular, and behavioral and ecological data: the Herpestinae (23 species of large, mostly solitary mongooses—habits are poorly known for many species, especially in Asia) and the Mungotinae (11 species of small, social mongooses). The subfamily Herpestinae includes the Yellow Mongoose (Cynictis penicillata), which exhibits some social but not "true" social behaviors (see Veron et al. 2004). At least three mongoose species are known to be fully social, regularly denning and foraging together as a group (although there are few, if any, examples of cooperative hunting among mongooses such as that seen in some other carnivores): the Meerkat (Suricata suricatta), the Banded Mongoose (Mungos mungo), and the Common Dwarf Mongoose (Helogale parvula). Several other species are believed to be fully social, but data are limited. Although many of the social mongooses live in open habitats, some are forest dwellers (the cusimanses (Crossarchus) and the Liberian Mongoose [Liberiictis kuhni]). The distinctive Meerkat was formerly placed in its own subfamily, but is now recognized as the sister taxon to all the other social mongooses and is included in the Mungotinae.

In some mongoose species, the male Y chromosome is attached to one of the autosomes. Thus, in these species females have one more chromosome than do males. Because such chromosomal translocations are rare, this may prove to be a useful character in inferring evolutionary relationships among mongoose species.

Mongooses swim well when they need to and several species, such as the Marsh Mongoose (Atilax paludinosus) in Africa and the Crab-eating Mongoose (Herpestes urva) in Asia, are semi-aquatic. Mongoose diets are varied (both between species and geographically within species, as well as seasonally), with some feeding largely on small vertebrate prey and others mainly on insects or even fruit; crustaceans and molluscs comprise a substantial part of the diet of the Marsh Mongoose. The social mongooses tend to feed more on insects and other invertebrates than do solitary species; at least in part, this is probably due to vertebrate prey densities being generally too low to support groups of mongooses. Mongooses are also known to feed on the eggs of ground-nesting birds, on carcasses, on human-generated garbage, and occasionally on domestic fowl.

The ability of mongooses to kill snakes was made famous in Europe and North America by Rudyard Kipling with the story of Rikki-Tikki-Tavi in the Jungle Book (much older tales involving snake-killing mongooses are known from India, such as that of The Brahmin and the Mongoose).  Although snakes are not known to be a significant part of the diet of any mongoose species, the speed and agility of mongooses allows them to kill snakes and at least some species, such as the Egyptian Mongoose (Herpestes ichneumon), are highly resistant (though not immune to) to snake neurotoxins. Fights between a mongoose and a snake (often a cobra) are often staged for tourists in towns and villages in parts of Asia. In the West Indies, fights may be staged between a Small Indian Mongoose (Herpestes auropunctatus) and a Bothrops viper (the viper often wins). In nature, mongooses, especially young ones, are probably more likely to be eaten themselves by large snakes such as African Rock Pythons (Python sebae) than to kill and eat snakes.

Several mongoose species have been introduced to various parts of the world as biological control agents. The Egyptian Mongoose is found in Spain and Portugal, but is not considered native there and may have been intentionally introduced from North Africa in the Middle Ages. The Indian Gray Mongoose (Herpestes edwardsii) was introduced to Japan in 1910 to control vipers and may also have been introduced to Mauritius. The Small Indian Mongoose has been introduced widely (mainly to islands) to control snakes and rodents (Simberloff et al. 2000 and references therein; Veron et al. 2010 and references therein). It was first introduced to the West Indies in the 1870s to control rats on sugar plantations as well as venomous snakes. Further introductions brought this species to the Hawaiian Islands, Adriatic Islands, Mautitius, and Japan.  Unfortunately, these introduced mongooses efficiently decimated much of the native bird, reptile, and amphibian fauna and also killed poultry. The Indian Brown Mongoose (Herpestes fuscus) was introduced to Fiji, probably in the late 20^th century, but the source of this introduction is uncertain (Veron et al. 2010).

Although introduced mongooses are themselves a major threat to biodiversity in many areas, some mongooses face their own threats from humans. They are a source of bushmeat in many small communities in Africa and Southeast Asia and are taken for the international pet trade. Habitat loss and fragmentation have likely taken a toll on many mongoose populations. Although some mongoose species, such as the Banded Mongoose, have a broad geographic and ecological range and appear to do well in human-modified environments, little is known about most mongoose species (e.g., the Liberian Mongoose, which was not discovered by western scientists until 1958, and the Angolan Cusimanse [Crossarchus ansorgei]. which  was known only from two specimens until 1984); most mongoose species have never been studied by scientists in the wild.

(Gilchrist et al. 2009 and references therein)