Characteristics, classification, habitat, importance and protection of mammals

Many mammals are partially aquatic, living near lakes, streams, or ocean shorelines (eg seals, sea lions, walruses, otters, muskrats, and many others). Whales and dolphins () are completely aquatic and can be found in all and some rivers. Whales can be found in polar, temperate and tropical waters, both near shore and in the open ocean, and from the surface of the water to depths of more than 1 kilometer.

The habitat of mammals is also characterized by different climatic conditions. For example, the polar bear lives calmly at sub-zero temperatures, while lions and giraffes need a warm climate.

Mammal groups

Baby kangaroo in mother's pouch

There are three main groups of mammals, each of which is characterized by one of the main features of embryonic development.

• Monotremes or oviparous (Monotremata) lay eggs, which is the most primitive reproductive feature in mammals.
• marsupials (Metatheria) are characterized by the birth of underdeveloped young after a very short gestation period (8 to 43 days). Offspring are born at a relatively early stage of morphological development. The cubs are attached to the mother's nipple and sit in the bag, where their subsequent development takes place.
• Placental (Placentalia) are characterized by long gestation (pregnancy), during which the embryo interacts with its mother through a complex embryonic organ - the placenta. After birth, all mammals depend on the milk of their mothers.

Lifespan

Just as mammals vary greatly in size, so does their lifespan. As a rule, small mammals live less than larger ones. Bats ( Chiroptera) are an exception to this rule - these relatively small animals can live for one or more decades in natural conditions, which is significantly longer than the lifespan of some larger mammals. Life expectancy ranges from 1 year or less to 70 years or more in the wild. Bowhead whales can live for over 200 years.

Behavior

The behavior of mammals varies significantly among species. Since mammals are warm-blooded animals, they require more energy than cold-blooded animals of the same size. Activity indicators of mammals reflect their high energy requirements. For example, thermoregulation plays an important role in the behavior of mammals. Those animals that live in colder climates need to keep their bodies warm, while mammals that live in hot and dry climates need to cool down to keep their bodies hydrated. Behavior is an important way for mammals to maintain physiological balance.

There are species of mammals that exhibit almost every type of lifestyle, including vegetative, aquatic, terrestrial, and arboreal. Their ways of moving around their habitat are varied: mammals can swim, run, fly, glide, and so on.

Social behavior also varies considerably. Some species can live in groups of 10, 100, 1000 or more individuals. Other mammals are generally solitary except when mating or rearing offspring.

The nature of activity among mammals also covers the full range of possibilities. Mammals can be nocturnal, diurnal, or crepuscular.

Nutrition

Most mammals have teeth, although some animals, such as baleen whales, have lost them during evolution. Because mammals are widely distributed in a variety of habitats, they have a wide range of feeding habits and preferences.

Marine mammals feed on a variety of prey including small fish, crustaceans, and sometimes other marine mammals.

Among land mammals there are herbivores, omnivores and carnivores. Each individual takes its place in.

Being warm-blooded, mammals require much more food than cold-blooded animals of the same size. Thus, a relatively small number of mammals can have a large impact on populations of their food preferences.

reproduction

Mammals tend to reproduce sexually and have internal fertilization. Almost all mammals are placental (with the exception of oviparous and marsupials), that is, they give birth to live and developed young.

Generally, most mammalian species are either polygynous (one male mates with several females) or promiscuous (both males and females have multiple matings in a given breeding season). Since females carry and nurse their offspring, it often happens that male mammals can produce many more offspring during the mating season than females. As a consequence, the most common mating system in mammals is polygyny, with relatively few males fertilizing many females. At the same time, a large number of males do not participate in reproduction at all. This scenario sets the stage for intense competition between males among many species, and also allows females to choose a stronger mating partner.

Many mammalian species are characterized by sexual dimorphism, whereby males are better able to compete for access to females. Only about 3% of mammals are monogamous and only mate with the same female each season. In these cases, males may even participate in the upbringing of offspring.

As a rule, the reproduction of mammals depends on their habitat. For example, when resources are scarce, males spend their energy breeding with a single female and provide food and protection for the young. If, however, resources are plentiful and the female can ensure the well-being of her offspring, the male goes to other females. In some mammals, polyandry is also common, when a female has bonds with several males.

In most mammals, the embryo develops in the uterus of the female until it is fully formed. The born cub is fed with mother's milk. In marsupials, the embryo is born underdeveloped, and its further development takes place in the mother's pouch, as well as feeding with mother's milk. When the calf reaches full development, it leaves the mother's pouch, but can still spend the night in it.

Five species of mammals that belong to the order Monotremes actually lay eggs. Like birds, representatives of this group have a cloaca, which is a single opening that serves for emptying and reproduction. The eggs develop inside the female and receive the necessary nutrients for several weeks before laying. Like other mammals, monotremes have mammary glands and females feed their offspring with milk.

The offspring need to grow, develop and maintain optimal body temperature, but feeding the young with nutrient-rich milk takes a lot of energy from the female. In addition to producing nutritious milk, the female is forced to protect her offspring from all sorts of threats.

In some species, the cubs stay with their mother for a long time and learn the necessary skills. Other species of mammals (such as artiodactyls) are already born quite independent and do not need excessive care.

Role in the ecosystem

The ecological roles or niches filled by more than 5,000 mammal species are varied. Each mammal has its place in the food chain: there are omnivores, carnivores and their prey - herbivorous mammals. Each species, in turn, affects. Due in part to their high metabolic rates, the impact that mammals have on nature is often disproportionate to their abundance. Thus, many mammals may be carnivores or herbivores in their communities, or play an important role in seed dispersal or pollination. Their role in the ecosystem is so diverse that it is difficult to generalize. Despite their low species diversity, compared to other groups of animals, mammals have a significant impact on the global.

Significance for a person: positive

Mammals are important to mankind. Many mammals have been domesticated to provide humankind with foods such as meat and milk (such as cows and goats) or wool (sheep and alpacas). Some animals are kept as service or pets (eg dogs, cats, ferrets). Mammals are also important to the ecotourism industry. Think of the many people who go to zoos or all over the world to see animals such as whales or whales. Mammals (eg bats) often control pest populations. Some animals, such as rats and mice, are vital to medical and other scientific research, while other mammals can serve as models in human medicine and research.

Significance for a person: negative

plague epidemic

Some species of mammals are believed to have a detrimental effect on human interests. Many species that eat fruits, seeds, and other types of vegetation are crop pests. Carnivores are often considered a threat to livestock or even human life. Mammals common in urban or suburban areas can become a problem if they cause damage to cars when they get on the road or become household pests.

Several species coexist well with humans, including domesticated mammals (eg, rats, house mice, pigs, cats, and dogs). However, as a result of the intentional or unintentional introduction of invasive (non-native) species into ecosystems, they have negatively affected the local biodiversity of many regions of the world, especially the endemic biota of islands.

Many mammals can transmit diseases to humans or livestock. The bubonic plague is considered the most famous example. This disease is spread by fleas carried by rodents. Rabies is also a significant threat to livestock and can also kill people.

Security

Overexploitation, habitat destruction and fragmentation, the introduction of invasive species and other anthropogenic factors threaten the mammals of our planet. Over the past 500 years, at least 82 species of mammals are considered extinct. About 25% (1,000) of mammal species are currently listed on the IUCN Red List, as they are at various risks of extinction.

Species that are rare or require large ranges are often at risk due to habitat loss and fragmentation. Animals known to threaten people, livestock or crops may die at the hands of humans. Those species that are exploited by humans for quality (for example, for meat or fur), but not domesticated, are often depleted to critically low levels.

Finally, it negatively affects flora and fauna. The geographic ranges of many mammals change due to changes in temperature. As temperatures rise, which is especially noticeable in the polar regions, some animals are unable to adapt to new conditions, and therefore may disappear.

Protective measures include tracking habitats and carrying out a set of measures to protect mammals.