Suncus murinus
Asian house shrew

Asian musk shrews (Suncus murinus) originated from the Indian subcontinent, ranging from southern Asia and Afghanistan to the Malay archipelago and southern Japan. This species has been introduced into northern and eastern Africa and the Middle East. Asian musk shrews are associated with forest environments, but are commonly found in household communities, and are considered commensals of humans. ("Suncus murinus", 2004)

This species is found in forested areas, in agricultural lands, and in areas associated with human activity. There have been many studies showing that S. murinus is found in many houses and businesses. It is primarily terrestrial. ("Suncus murinus", 2004; Mushtaq-Ul-Hassan-Muhammad, et al., 1999)

Nesting occurs wherever possible. In the forest/agricultural habitat, these shrews gather leaves and any other nesting material available, then find a hidden area (snag) in which to build the nest. In a house or business this species nests in dark hidden areas, and uses any type of loose material that can be found for nest construction. (Mushtaq-Ul-Hassan-Muhammad, et al., 1999)

Asian musk shrews vary widely in color, size, and weight. They are mouse-like in appearance, with a long pointed nose. The fur color varies, with some individuals light gray to those which are black. Pelage is short and has a velvety texture. ("Suncus murinus", 2004; Chang-Chun-Hsiang, 1999)

The weight of an adult female ranges between 23.5 g and 82.0 g. Males are much heavier, weighing in from 33.2 g to 147.3 g. Asian musk shrews are very small in size. Total body length of adults typically varies between 100 mm and 150 mm, including the tail. The males have a large, well-developed scent gland, from which is derived the strong, musky odor, for which they received their common name. ("Suncus murinus", 2004; Chang-Chun-Hsiang, 1999)

No information was found on the mating system of Asian musk shrews. Size dimorphism between males and females suggests that they may be polygynous. However, both males and females are known to collect nesting material prior to parturition, suggesting that mating may be monogamous. Another member of the same genus, Suncus varilla, is reported to be monogamous. (Nowak, 1999)

Reproduction occurs year round, with peaks in the spring and summer. There is no behavioral estrus cycle. Development of follicles and ovulation are induced by mating. The sperm spends a long period in the female's reproductive tract before fertilization occurs. The gestation period is usually 30 days and litter size varies from 4 to 8. The young stay in the nest until they are about 75% grown. Weaning occurs between 15 and 20 days, although young can survive forced weaning as early as 12 days of age. Females reach sexual maturity around 35 days. ("Suncus murinus", 2004; Mushtaq-Ul-Hassan-M, et al., 2000; Nowak, 1999)

Both parents gather nesting material and the young do not leave the nest until seventy-five percent grown. As mammals, the female provides the offspring with milk, and probably grooms them while they are in the nest. Little is known about male parental care, beyond the gathering of nesting material. ("Suncus murinus", 2004; Nowak, 1999)

The lifespan of S. murinus in captivity ranges from 1.5 to 2.5 years. However, shrews generally live between one and two years of age in the wild. ("Suncus murinus", 2004; Nowak, 1999; Schmidt, 1994)

This is a robust and highly adaptable species. Because of this, theese shrews colonize at high densities. These shrews are nocturnal and active year round. They are typically terrestrial, and are thought to be mainly solitary. ("Suncus murinus", 2004)

The home range size for these animals has not been reported.

Shrews apparently are solitary and intollerant of conspecifics. Their vocal sounds include a high proportion of chirps and buzzes, sounds that seem to be associated with aggressive behavior. In China S. murinus is known as the "money shrew" because of a resemblance between its rather constant, small chattering noises, and the sound of jingling coins. (Nowak, 1999)

In addition to vocal communication, these animals are likely to use some chemical cues in communicating, especially the males, which have very pronounced scent glands. ("Suncus murinus", 2004; Nowak, 1999)

Other forms of communication in these animals must be inferred from the fact that they are mammals. Tactile communication probably occurs between mates, between mothers and their young, and between individuals in aggressive encounters. Because they are mammals, these shrews have some ability to see, although shrews are not known for having well-developed eyes. So, although some visual signals may exist in this species, they are probably not as important as other forms of communication. (Nowak, 1999)

Suncus murinus is mainly insectivorous. Eighty-two percent of their diet constitutes insects and mammals. Asian musk shrews are also known to be opportunistic feeders. In most areas, they feed on plant material and also tend to eat a wide variety of invertebrates and human food items. They are nocturnal and feed mostly at night in forests, cultivated fields, and human populated areas. ("Suncus murinus", 2004; Prakash-Ishwar and Singh-Himmat, 1999)

Like many other shrews, this species has a high metabolic rate, and requires multiple feeding periods. ("Suncus murinus", 2004; Prakash-Ishwar and Singh-Himmat, 1999)

Suncus murinus has few predators because of its well-developed scent gland. This gland produces a strong odor of musk that inhibits many possible predators. Among notable predators are brown tree snakes. (Pickett, 1995)

Suncus murinus is a dominant species in the mammal population in its natural environment. It undoubtedly affect many insect populations due to its voracious feeding behavior. (Prakash-Ishwar and Singh-Himmat, 2002)

Predation on many insects is an important role in musk shrews, and probably helps to curb the population of many pest species. These shrews are also being used as a potential medical models for humans, especially in the study of periodontal disease in humans. Other research uses of S. murinus include behavioral studies in comparative psychology and related fields. ("Suncus murinus", 2004; Takata-Takashi, et al., 1999; Tsuji-Keiichiro, et al., 1999)

Suncus murinus is an invasive species. They have a rapid reproductive rate, and they are not eaten by many potential predators because they are so smelly. These shrews are a growing ecological threat, preying upon or competing with many plant and animal species. Due to high densities in household areas, this species is labeled as a pest and can be very damaging to foods and other materials found in homes and businesses. ("Suncus murinus", 2004; Takata-Takashi, et al., 1999; Tsuji-Keiichiro, et al., 1999)

This species is listed as an invasive species and is not protected. This species is trapped and poisoned in domestic areas. Dogs may also be used to eliminate this species in these areas. ("Suncus murinus", 2004)

Asian house shrews have many other common names associated with it such as: house shrew, Indian musk shrew, kirkanjia. ("Suncus murinus", 2004)