Warm-blooded

As equally warm, warm-blooded or homoiotherm (Greek ὁμοῖος homoios "similar"; θερμός thermos " hot "; well homöotherm ) animals in zoology called that regulate their own body temperature (birds, mammals) or for other reasons ( deep sea fish), a constant exhibit temperature.

In organisms, such as birds and mammals endothermic uniform body temperature is produced by the metabolic activity of the animals. This manifests itself particularly in the basal metabolic rate of metabolism ( see also micro-vibration ). Same- Warm animals with the same body weight significantly higher basal metabolic rate ( energy consumption per unit of time ) than ectothermic animals ( poikilothermic animals). When deep sea fishing, however, the body temperature depends only on the outside temperature. Since the water in the deep ocean but always has the same low temperature, they are ektotherm while homoiotherm.

Regulatory mechanisms in the body ensure the constancy of the temperature and that, for example, at elevated ambient temperature heat is dissipated. This is often done by the evaporation of liquids, for example in people through sweating, panting in other species (dogs ) or licking ( cats).

Equal Warm animals require a special heat insulation in the rule. In terrestrial animals this is accomplished primarily by the inclusion of a layer of air in feathers or hair.

• In birds, this is particularly achieved by the feathers. Special insulation effect have here the down, which are therefore processed to down garments, duvets and sleeping bags.
• In terrestrial mammals, this is achieved through the coat ( fur ). Special insulation is achieved by the wool fibers, which are stronger than the guard hairs coiled and thus can have more air.
• Living water mammals such as whales and seals as well as some birds ( penguins ) have an insulating layer of fat ( " Blubber " ), as feathers and hair lose much of their insulating effect in the water.
• In some species of dinosaur feathers were found. It is therefore assumed that they were at least partly homoiotherm.

Some mammals are not homoiotherm in the strict sense. Thus, decreases in species that hold hibernating, the body temperature in this phase often by more than 10 ° C.. This saves these animals in a period of inactivity energy and can survive with or without ( in wakefulness ) with low food intake for several months. Examples are hedgehogs and dormice. Once the body of the animal homoiothermen noted that he falls into a state of hibernation (below 10 ° C), the metabolism of the animal is set in motion, so that the living entity again at a temperature sufficient.

Also, some insects have developed approaches to warm-blooded. So keep the honey bees, the temperature of the breeding range of her hive by muscle tremors of individual workers constant at 35 ° C, even in freezing temperatures. At high summer heat by water evaporation and Luftzufächern is cooled accordingly ( by flapping their wings ). In this case, the warm-blooded does not refer to the individual insect, but to the entire state. A single bee already solidified at a temperature of 10 ° C and dies (see also Western honey bees: specificity in metabolism ).

Hummingbirds, platypus, large flying insects and big fish are, however, referred to as poikilotherm because their body temperature changes, being also dependent on the metabolic intensity to some degree. However, there are tuna, some sharks ( Alopias ) and rays blood vessel changes ( counter-current ) in the core muscles, which allow a higher core temperature, and for others ( swordfish, gloss fish) the brain is supplied with heated blood.

Relatively unknown, that there are homoiotherme plants, such as the " Skunk Cabbage " ( Symplocarpus foetidus ) and other Arum plants that can maintain a constant inner temperature of 20 ° C even at outside temperatures below 0 ° C, as in the mitochondria of the flower bud heat is generated.