House mice are rodents living in people's homes. In the photo, the house mouse looks like ordinary mice. Is there a difference between them?
Since house mice perfectly adapted to human existence, they were able to spread around the world, thus becoming one of the most common mammals. Mice are also domestic animals and model organisms for laboratory research.
The appearance of the house mouse
The house mouse is a long-tailed small rodent with a body length of 6.5 to 9.5 cm. Relative to the length of the body of the tail is less than 60%.
The top is covered with ring-shaped horny scales and short sparse hairs. The weight of an adult is from 12 to 30 grams. The ears are small and rounded. The skin has a brownish-gray or dark color. The color of the abdomen is from white to ash gray. Desert mice have a light yellowish-sand color and a white abdomen.
Domesticated mice are variegated, gray-blue, yellow, black or white. Females have five pairs of nipples. In the house mouse, sexual dimorphism is not expressed.House mouse (Mus musculus).
Distribution of house mouse and its subspecies
The house mouse is a cosmopolitan species and lives almost everywhere. It is absent only high in the mountains, Antarctica and the Far North. The main factors that limit the spread of house mice are high humidity and low temperatures. In Russia, the house mouse is not found in the mountain tundra, between the rivers Lena and the Yenisei, in Taimyr, in most of northeastern Siberia.
Presumably the home mouse homeland is North Africa, Front Asia or North India. In West Asia, the house mouse is known to be fossil. Around the world, the house mouse has spread with humans.House mice have spread around the world and are one of the most numerous species of mammals.
Currently, about one hundred and thirty subspecies of the house mouse has been described. They are combined into four main subspecies.
1. M.m. castaneus - lives in Southeast Asia;
2. M.m. bactrianus - lives in Asia with the exception of the Southeast region;
3. M.m. domestic - distributed in Australia, America, Europe and most of Africa;
4. M.m. musculus - lives in eastern Europe starting from the territory of Poland and further eastward occupying most of Russia.
For a long time, it was believed that the Japanese subspecies M.m. molossinus is the fifth “main” subspecies, however, according to recent studies, it is a hybrid between M.m. castaneus and M.m musculus.
Interestingly, in ancient Rome, mice and rats were considered the same species, so rats were called simply a big mouse.
House mouse lifestyle
House mice live in a wide variety of biotopes and landscapes, including man-made. In general, it can be argued that house mice are very closely related to humans and are synanthropic species. The house mouse often settles in farm buildings and residential buildings. In the north of their range, mice make seasonal migrations. At the end of the summer period or at the beginning of autumn, animals begin to migrate en masse to the so-called "feeding places", which include warehouses, grain and vegetable stores, as well as residential buildings. In autumn, the range of migrations can reach up to five kilometers. Often house mice hibernate in ricks, haystacks, and forest belts.Domestic mice are kept as domestic animals, in addition, they are model organisms in laboratory studies.
In spring, house mice leave their wintering grounds and return to their natural habitats, gardens, gardens and fields. In the south of the range, in semi-deserts and deserts, they often live outside human habitation throughout the year. In such conditions, house mice gravitate to various ponds and oases.
In natural habitats, the house mouse prefers soft, not too dry soils. In them they dig small holes with a simple device. The length of the hole reaches one meter, and the nesting chamber is located at a depth of 20-30 centimeters and has from one to three entrances. In the winter, mice often deepen burrows to 50-60 centimeters. The diameter of the nesting chamber is from ten to twenty-five centimeters. Inside the chamber, the animals arrange the litter using soft plant rags. Often house mice are occupied by burrows belonging to other rodents: gerbil, blind, vole. Cracks in the earth and natural voids are also used for housing.
House mice settled next to people equip their homes in the most protected and secluded places. Most often they live in attics, in household waste, piles of garbage and under the floor. For arranging nests, house mice use any available material: artificial fibers, feathers, scraps of fabric, paper.
It should be noted that house mice diligently maintain cleanliness in their nests. If the litter is very dirty, wet or infected with parasites, then the mice drop the old nest and move to a new one.
Under natural conditions, house mice lead a nocturnal and twilight lifestyle. But living near a person, they adjust the daily regimen depending on the nature of human activity. With artificial lighting, a house mouse can maintain round-the-clock activity, reducing it only in those periods when people show activity themselves. The activity of the house mouse in this case is polyphase in nature: within one day there can be fifteen to twenty periods of wakefulness lasting from twenty-five minutes to one and a half hours. Like many other members of the murine family, house mice tend to have constant routes when moving around.
Such routes are easy to track thanks to noticeable piles of dust and droppings that are held together by urine.Mice live everywhere, except for the Far North, Antarctica and highland areas.
The house mouse is a very nimble, moving animal. They run fast enough, developing speeds of up to 13 km / h, jump well, climb and are good swimmers. However, they are rarely removed from their nests. In vivo, each mouse has its own individual plot. In males it reaches 1200 sq.m, and in females it reaches 900 sq.m. However, if the population is sufficiently dense, mice prefer to settle in family groups, which consist of one dominant male, as well as several females with their offspring or small colonies.
Relations within the colony are hierarchical in nature. In relation to each other, adult males are quite aggressive. In contrast, females are much less aggressive. Clashes within the family group are rare, and as a rule they come down to expelling the offspring.
House Mouse Power
In vivo, the house mouse is a typical eater. The seeds of cultivated and wild plants serve as feed. Preference is given to seeds of Asteraceae, legumes and cereals.At present, about 130 subspecies of house mice have been described.
The diet of the house mouse also includes carrion, insects and their larvae. Green parts of plants are also eaten, which, depending on how accessible drinking water is, can make up to a third of the food consumed. A house mouse consumes up to three milliliters of water daily. If the relative humidity was about thirty percent, and the food was exceptionally dry, then during the experiment the laboratory mice died from dehydration on days 15-16.
With great desire, the mice feed on dairy products, chocolate, meat or grain. Under natural conditions, subject to excess feed, stocks are made.
House mouse breeding
The house mouse is extremely fertile. If the conditions are favorable (for example, in ricks and heated rooms), then it can reproduce throughout the year. Under natural conditions, the breeding season lasts from March to November. Re-entry into estrus is observed in females already 12-18 hours after the birth of the offspring. Within a year, a house mouse can bring from five to fourteen offspring. In each litter, there are from three to twelve cubs.
Pregnancy lasts about twenty days (19-21). Cubs are born naked and blind. After about ten days, their bodies are completely covered with hair. After two weeks of life, their eyes open, and at the age of three weeks they become independent and capable of resettlement. The house mouse reaches puberty in the fifth to seventh week of life.Mice bring 5-10 offspring per year. Mice are born blind and naked.
It should be noted that males, trying to attract a female, emit ultrasonic cries of 30 - 110 kHz. In their complexity, these cries are comparable to the singing of birds. The house mouse easily interbreeds with the Kurgan mouse, which lives, for example, in the Black Sea region.
Offspring from such crosses are quite normal and viable. A number of zoologists consider the mound mouse a subspecies of the house mouse.
House Mouse Enemies
The house mouse has many enemies, primarily predators. These are birds of prey, snakes, large lizards, mongooses, small representatives of the marten family, foxes, cats, crows and even shrieds.
Serious competition for house mice is rats, which often kill and even partially eat their small relatives.In nature, house mice are twilight and nocturnal animals, however, in human housing, they adjust their daily regimen to the activities of people.
At the same time, mice themselves can act as predators, which is generally unusual for them.
Once, on the island of Gough, located in the south Atlantic, mice were accidentally brought in, which took root there. Since there were no natural enemies on the island, they multiplied very quickly and now their population is estimated at 0.7 million individuals. It should be noted that these island mice are three times larger than their mainland counterparts. They unite in groups and attack them on bird nests, eating chicks.
I must say that the island of Gough is an important colony of marine birds, among which you can mention birds such as Typhoon Schlegel and albatross. Nowhere else do these birds nest. However, despite the fact that albatross chicks can reach a height of one meter and weigh 250 times more than the mice of this island, they practically do not move and are unable to protect themselves.Mice diligently maintain cleanliness in their nest.
As a result, mice literally gnaw through the bodies of the chicks and inflict deep wounds on them. According to scientists, annually mice kill more than a million chicks on this island.
House mouse lifespan
Under natural conditions, the life expectancy of these rodents is a year and a half. However, in captivity they are able to live up to three years. The record for life expectancy is almost five years (1819 days).
The sense organs of the house mouse
The sense organs of these rodents are very well developed. True, the vision in the house mouse is rather weak.House mice, living next to people, eat almost any food, including glue, candles, soap.
Like most other rodents, they are characterized by farsightedness. Moreover, they have a very keen ear. The range of frequencies they perceive is very wide - up to 100 kHz. For comparison, the upper human threshold is 20 kHz. In low light, the house mouse is perfectly oriented with the help of vibrissae. The role of olfaction is extremely high in the life of mice, which is necessary both for finding food and for recognizing relatives.
Each mouse has sweat glands on its paws, with the help of which they automatically mark the territory. If the mouse is very frightened, then a substance is produced in the urine that causes fear and flight in other animals. Moreover, the smell is quite stable, and lasts up to a quarter of a day, informing other mice about the insecurity of this place.
Moreover, if the signaling substance was left by the male, then all individuals react to it, whereas the females react exclusively to the label of the female, while the males ignore it.
House mouse and man
House mice are pests and carriers of a number of dangerous infections, such as plague, etc. At the same time, mice play a very important role as laboratory animals. On 1.07.2013, a laboratory mouse monument was erected in Novosibirsk for its contribution to experimental medicine and genetics.