Any kind of organisms is able to live only within a certain temperature range, within which temperature conditions are most favorable for its existence, and its vital functions are carried out most actively. As we approach the boundaries of the temperature range, the speed of life processes slows down, and beyond it they completely stop – the body dies. The limits of temperature endurance in different organisms are different. Some species can tolerate significant temperature fluctuations. For example, lichens and many bacteria can live at very different temperatures. Among animals, the largest temperature range is maintained by warm-blooded animals. The tiger, for example, tolerates both the Siberian cold and the heat of the tropical regions of India or the Malay archipelago equally well. In the ground-air and even in the aquatic environment, the temperature does not remain constant and can vary greatly depending on the season of the year or time of day. In the tropics, daily temperature fluctuations can be more pronounced than seasonal. Conversely, in temperate regions, temperature varies significantly at different times of the year.
Water is an integral part of every living organism, it is necessary for its normal functioning. For most of its history, wildlife was represented exclusively by aquatic organisms. Having conquered the land, they nevertheless did not lose their dependence on water. Plants extract the water they need from the soil using the roots. Lichens can trap water vapor from the air. All land animals in order to compensate for the inevitable loss of water due to evaporation or excretion require periodic supply. Many of them drink water, others, such as amphibians, some insects and mites, absorb it through the integument of the body in a liquid or vapor state. There are animals that can receive water in a rather complicated way – in the process of fat oxidation. This, for example, a camel and some types of insects – rice and barn weevils, clothes moth, eating fat. Animals, like plants, have many devices for saving water.
The light of the sun is almost the only source of energy for wildlife. Compared to temperature or humidity, light has almost no direct effect on animals. It serves only as a signal for the restructuring of the processes occurring in the body, which allows them to best respond to ongoing changes in external conditions. In many animals, lighting conditions cause a positive or negative reaction to light. Some insects (nocturnal moths) flock to the light, others (cockroaches) avoid it. Of greatest environmental importance is the change of day and night. Many animals lead exclusively daily life (most birds), others – exclusively nocturnal (many small rodents, bats, etc.). Small crustaceans soaring in the water column stay at night in surface waters, and during the day they sink to the depth, avoiding too bright light.
Secondary climatic factors – wind, atmospheric pressure, altitude, etc. – are also important in a particular place (area) of the living organisms of each species. For example, the wind has the following indirect effect: enhancing evaporation, it dehydrates the body; Strong winds also contribute to cooling. This is important in cold places, in the highlands or in the polar regions.