Today, let's talk about it.
Energy sources of carnivores
We know that tigers and lions are recognized as the kings of beasts, but do you know that their living conditions are not good? For example, in order to survive, lions often compete with hyenas for carrion.
The reason for this is that the energy available to carnivores is really too low.
We know that the energy source of human beings is the meat of plants and poultry, among which the energy source of poultry is plants and the energy source of plants is sunlight.
Plants can convert solar energy into bioenergy through photosynthesis, so plants can obtain energy independently of other organisms. Biologically, this is called producer, while human beings and other organisms that need to obtain energy directly or indirectly from plants are called consumers, and of course there are decomposers such as microorganisms.
Energy flows between producers, consumers and decomposers in this way, but when energy flows, it will produce a lot of waste. For example, human beings are consuming energy when breathing and walking.
This means that 100% energy cannot be transferred from plants to herbivores, and 100% energy cannot be transferred from herbivores to carnivores.
The efficiency of energy transfer between each living thing is very low, only about 5%-20%. Therefore, the higher the food chain pyramid, the less energy you can get, especially large carnivores such as tigers and lions, because they don't eat plants, they just eat meat.
Because the energy sources of tigers and lions are very limited, they don't need to breed a large number of offspring, which will not only waste energy during pregnancy, but also cause a large number of offspring to die because of food shortage.
Therefore, carnivores will only reproduce about 1-4 at a time, and will not be in estrus again until their offspring grow up, and there may be an interval of about 2-4 years.
Why do herbivores breed more offspring?
The reproductive rate of herbivores is higher than that of carnivores because they face different environments.
As first-class consumers, herbivores have a wide range of food sources, but they need to face harassment from natural enemies during their growth, especially underage individuals.
This has caused a large number of underage individuals to be captured by carnivores because of their lack of speed, agility and size, and only a few adults can grow to adulthood.
In order to ensure their own race is not extinct, herbivores must improve their reproduction rate and produce enough offspring at a time to cope with the fact that the mortality rate of offspring is high.
In order to improve the survival rate of offspring, herbivores have tried everything, such as estrus.
If you carefully observe the estrus of the animal kingdom, you will find that they will give birth to offspring in the season when there is enough food, so that the offspring will not be hungry.
Some insects will choose to breed in the season when natural enemies fly south. Such measures can improve the survival rate of future generations.
Due to the existence of carnivores and seasonal food shortage, the number of herbivores has remained relatively stable.
For example, rabbits have double uterus and can be pregnant at the same time. Each fetus can produce 4-6 rabbits and reproduce twice a year. However, due to the large number of natural enemies of rabbits, even if the breeding speed is so fast, they are still not submerged in the country of origin. Only in Australia, where there are no natural enemies, can it show strong reproductive ability.
However, not all herbivores have a high reproductive rate. Generally speaking, the bigger the creature, the fewer offspring each child has. This is because the bigger the creature, the higher the demand for energy.
The number of carnivores and herbivores
Although the number of carnivores is generally less than that of herbivores, when the number of herbivores increases, the number of carnivores will also increase. For example: lynx.
Because the main food source of lynx is rabbits, biologists have made a dynamic change diagram of the number of rabbits and lynx, which is also called the relationship diagram between predation and the number of prey animals.
According to this model, it can be seen that the number of lynx will increase every 1-2 years after the number of rabbits increases; When the number of rabbits decreases, the number of lynx will also decrease. Generally speaking, lynx and rabbit have a population peak every 10 year.
So is the tiger and its ecological chain. When the earth's climate is suitable and plants are flourishing, the survival rate of offspring of herbivores will be higher because of rich food sources, so more offspring will survive to adulthood.
When the number of herbivores increases, it will also cause carnivores to have more energy sources, so their numbers will also increase.
abstract
The reason why the reproduction rate of carnivores is low is that they can get limited energy from nature, even if they breed a large number of offspring, they can't survive, but they will waste a lot of energy when they breed offspring. Over time, the genes with high reproduction rate are abandoned by carnivores, on the contrary, the genes that can help future generations survive better are retained.
The high reproduction rate of herbivores is due to the abundant food sources, but the offspring are restricted by natural enemies, so the survival rate is low. Only by breeding a large number of offspring can we ensure that enough individuals survive to adulthood and participate in the next reproduction.