Mammals are the most highly developed and progressive creatures of all that inhabit the earth. The number of known and living species is about 5,500, and if we take into account those that have become extinct - 20 thousand. According to several modern taxonomists, the class unites 26-29 orders. Representatives of Mammalia have spread everywhere.
Rodents are the most numerous order of mammals. It's no joke, but now 2277 species have been described by zoologists, and this is more than half of all animals and first animals. Rodents have spread throughout the planet, with the exception of Antarctica and some islands. They are not only carriers of dangerous diseases and pests, but also a valuable source of fur, an object of fishing and research, etc. Their role in ecosystems is ambiguous and multifaceted, while the knowledge of most people is limited only to “acquaintance” with domestic mice and rats.
General characteristics
Rodentia isthe Latin name of the most numerous detachment of mammals, literally it translates as "gnaw, gnaw." A characteristic feature of all rodents is a pair of large incisors on the lower and upper jaws, as well as a diastema, i.e. a disproportionately large gap between them.
Rodents are not large. The smallest are mice - from 5 cm in length, the largest are capybaras (pictured below), up to 130 cm, but, as a rule, about 50 cm. Moreover, the tail is often much longer than the body. In some species, such as the guinea pig, it is absent. The shape of the limbs and body depends on lifestyle and can vary greatly. Jumping forms (jerboas) have strongly developed hind legs. Burrowing species have a roller-shaped body and have claws on the forelimbs (moles, shrews). Gliding species (flying squirrel) have a lateral skin fold.
As already mentioned, a distinctive feature of the representatives of the most numerous detachment in the class of mammals is a pair of incisors on the lower and upper jaws. The incisors are constantly grinding down and growing, they do not have roots. In particular, in beavers (pictured below), their growth rate reaches up to 0.8 mm per day. There are no canines and the incisors are separated from the small molars by a distance - a diastema.
Lifestyle & Nutrition
Most often, rodents show activity at night or at dusk. They live both in large groups of up to hundreds of individuals (naked mole rat), and alone. They have mastered all living spaces, includingnumber and air.
The bulk of the species of the most numerous order of mammals are herbivorous animals. Depending on the season and habitat, they eat all parts of the plant: bark, leaves, stems, seeds, roots and fruits. There are also omnivorous species (dormouse, mice, mole rats), whose diet includes insects, worms, small vertebrates, bird eggs.
Meaning of rodents
More than half of the mammal species on the planet are rodents. It is logical that they play a huge role in ecosystems. Rodents are an important food source for predators, colonies are constantly replenished due to rapid reproduction. Normal rats are ready to mate immediately after the birth of the pups, and the pregnancy lasts about 25 days.
Representatives of the largest order of mammals have been accompanying man since time immemorial, therefore their significance in our life is very diverse:
- Research field. Ease of maintenance and high reproduction rate have made rodents suitable animals for laboratory research.
- Disease vectors (bubonic plague, listeria, toxoplasmosis, tick-borne encephalitis, etc.).
- Pets. Many types of rodents are kept at home: rats, mice, hamsters, chinchillas, guinea pigs.
- Source of fur. Many rodents are game animals due to their light and pleasant to the touch fur (chinchilla, squirrel).
- Crop pests.
Rodents in the Red Book
BThe following rodents are listed in the Red Book of Russia: tarbagan, river beaver, black-capped marmot, Manchurian zokor, giant mole rat, yellow pied. These species are recognized as endangered and endangered. This is largely due to human economic activity.
Soni (polkok, garden and hazel or mushlovka), flying squirrel (pictured), common hamster and speckled ground squirrel are rodents listed in the Red Book of the Republic of Belarus. The largest order of mammals in the Republic of Belarus is represented by only 26 species, and six of them need protection.
In Ukraine, the Red Book includes: ground squirrel (Podolsky, European and speckled), mole rat (Bukovinsky, Podolsky, sandy and white-toothed), large jerboa, common eumaranchik, mouse (Stranda, steppe, dark and forest), hamster (gray and common), vole (Tatra and snow), common mole vole, steppe pied, garden dormouse.
