Caring for offspring in living organisms. Caring for the offspring of animals

As is known, for the successful existence of a biological species, each generation of its representatives must leave behind offspring capable of reproduction. The success of its survival depends to a great extent on the adequacy of the parents' behavior, which is an important factor in natural selection. During the process of childbirth and the subsequent process of caring for the offspring, mainly instinctive behavior is realized. For example, immediately after the fetus emerges from the birth canal, the female mammal frees it from the membranes, gnaws the umbilical cord, eats the membranes and placenta, and actively licks the newborn. The cubs of a female who does not provide primary care for them are doomed to death in nature, and this trait, which is largely hereditary, is eliminated with them.

The success of offspring survival depends to a great extent on the adequacy of parental behavior, which is an important factor of natural selection. Caring for the offspring of many animals begins with preparation for their birth. Often seasonal migrations animals are associated with movement to breeding grounds, sometimes many thousands of kilometers from their habitat. Animals that do not make such long journeys also choose their nesting territory in advance, and many of them carefully guard it and prepare shelters - nests, burrows, dens, adapted for future offspring.

Types of care for offspring

In the animal world, there are a variety of forms of care for offspring: from complete absence to the most complex and long-term relationships between children and parents. In its simplest form, care for the offspring is present in all organisms and is expressed in the fact that reproduction occurs only in conditions favorable for the offspring - in the presence of food, suitable temperature, etc.

1. Complete lack of care for the offspring. Most invertebrates and fish do not care for their offspring. Successful existence similar types ensures their mass reproduction. In the vastness of the ocean, many species of invertebrates and fish, gathering in giant schools, lay millions of eggs, which are immediately eaten by a huge variety of carnivorous creatures. The only salvation for such species is colossal fertility, which still allows the minimum number of descendants necessary for the existence of the population to survive and reach adulthood. The number of eggs in many species of fish that lay eggs in the water column is estimated in hundreds and millions. So, the female living in northern seas large sea pike - moths - spawn up to 60 million in one season, and the giant sea sunfish, weighing one and a half tons, throws up to 300 million eggs into the ocean waters. Fertilized eggs presented by chance, mixing with plankton or sinking to the bottom, die in countless quantities. The same fate befalls the larvae hatched from the eggs.

2. Carrying eggs laid on the body of one of the parents. The females of many marine animals attach the laid eggs directly to their bodies and carry them, as well as the hatched young, until they become independent. Similar behavior is observed in many aquatic animals: starfish, shrimp and other crustaceans. This behavior represents the next step in the complexity of caring for offspring, but in general it is not particularly inventive.

The number of eggs laid is inversely proportional to the level of parental care. This pattern is well confirmed by sea stars, among which there are both species that lay eggs directly into the water, where they are fertilized by the sperm of several males, and species that carry eggs on their bodies. In species of the first group, the number of eggs maturing in the female’s body reaches 200 million, while in sea stars that take care of their offspring, the number of eggs laid does not exceed several hundred.

4. Construction of nests and their protection until the birth of offspring. A more advanced type of care for offspring can be considered the construction of a nest, laying eggs or eggs there and protecting it until the growing young leave it. This behavior is typical for a number of species of fish, spiders, octopuses, some centipedes, etc. A similar level of care includes the brooding of eggs and fry in the mouth by males of some fish, as well as eggs and tadpoles on the hind legs of a midwife toad or on the back of a male pippa of Suriname. In this case, the oral cavity or back serves as a nest. This level is characterized by a lack of any interest on the part of parents in the young, which are just gaining independence.

5. Caring for the offspring until they gain independence. Long-term care for offspring is observed in some species of invertebrates and fish. The care of offspring among social insects reaches great perfection.

Many examples different types Amphibians demonstrate parental behavior. In higher vertebrates there are different ways care for the offspring, which depend, first of all, on the level of maturity of newborns.

In the most general outline Among them, the following groups of parental behavior can be distinguished:

raising offspring by one female or one male;

raising offspring by both parents;

raising young in a complex family group.

As is known, for the successful existence of a biological species, each generation of its representatives must leave behind offspring capable of reproduction. During the process of childbirth and the subsequent process of caring for the offspring, mainly instinctive behavior is realized. For example, immediately after the fetus emerges from the birth canal, the female mammal frees it from the membranes, gnaws the umbilical cord, eats the membranes and placenta, and actively licks the newborn. The cubs of a female who does not provide primary care for them are doomed to death in nature, and this trait itself, which is largely hereditary, is eliminated with them.

The success of offspring survival depends to a great extent on the adequacy of parental behavior, which is an important factor of natural selection. Caring for the offspring of many animals begins with preparation for their birth. Often seasonal migrations of animals are associated with movement to breeding grounds, sometimes many thousands of kilometers from their habitat. Animals that do not make such long journeys also choose their nesting territory in advance, and many of them carefully guard it and prepare shelters - nests, burrows, dens, adapted for future offspring.

Types of care for offspring

In the animal world, there are a variety of forms of care for offspring: from complete absence to the most complex and long-term relationships between children and parents.

Complete lack of care for offspring

Let us note that in its simplest form, care for the offspring is present in all organisms and is expressed in the fact that reproduction occurs only in conditions favorable for the offspring - in the presence of food, suitable temperature, etc. Subsequently, most invertebrates and fish do not take care of their offspring. The success of the existence of such species is ensured by their massive reproduction. In the vastness of the ocean, many species of invertebrates and fish, gathering in giant schools, lay millions of eggs, which are immediately eaten by a huge variety of carnivorous creatures. The only salvation for such species is colossal fertility, which still allows the minimum number of descendants necessary for the existence of the population to survive and reach adulthood. The number of eggs in many species of fish that lay eggs in the water column is estimated in hundreds and millions. Thus, the female of the large sea pike living in the northern seas, the moth, spawns up to 60 million eggs in one season, and the giant sea sunfish, weighing one and a half tons, throws up to 300 million eggs into the ocean waters. Left to chance, fertilized eggs mix with plankton or sink to the bottom and die in countless quantities. The same fate befalls the larvae that hatch from the eggs, but there are still enough survivors to maintain the population of the species.

Carrying eggs laid on the body of one of the parents

The females of many marine animals attach the laid eggs directly to their bodies and carry them, as well as the hatched young, until they become independent. Similar behavior is observed in many aquatic animals: starfish, shrimp and other crustaceans (Fig. 12.9). This behavior represents the next step in the complexity of caring for offspring, but in general it is not particularly inventive.

Rice. 12.9.

passive way of caring for offspring

Laying eggs in an environment previously found or specially prepared by the female

Construction of nests and their protection until the birth of offspring

A more advanced type of care for offspring can be considered the construction of a nest, laying eggs or eggs there and protecting it until the growing young leave it. This behavior is typical for a number of species of fish, spiders, octopuses, some centipedes, etc. A similar level of care includes the brooding of eggs and fry in the mouths of male fish, as well as the eggs and tadpoles on the hind legs of the midwife toad. The described level is characterized by a lack of any interest on the part of parents in juveniles gaining independence.

Rice. 12.10.

Caring for offspring until they gain independence

Long-term care for offspring is observed in some species of invertebrates and fish. The care of offspring among social insects reaches great perfection.

Amphibians demonstrate many examples of different types of parental behavior (Fig. 12.10). In higher vertebrates, different ways of caring for offspring are observed, which depend primarily on the level of maturity of newborns. In the most general terms, the following groups of parental behavior can be distinguished among them:

– raising offspring by one female or one male;
– raising offspring by both parents;
– raising young in a complex family group.

In order for a species to continue to exist, each generation must leave behind offspring capable of reproduction. Most invertebrates and fish do not care for their offspring. They simply lay out thousands of eggs, only some of them produce young, and an even smaller number grow and reproduce. A more reliable way to continue the race is to provide them with food, protect them from predators, and even teach them some skills after the birth of a limited number of cubs. Care for the offspring is shown in different forms many animals. Most of them are endowed with special parental instincts, but in highly organized animals, individually acquired experience is also important.

In its simplest form, care for the offspring is present in all organisms and is expressed in the fact that reproduction occurs only in conditions favorable for the offspring - in the presence of food, suitable temperature, etc.

Caring for the offspring of many animals begins with preparation for their birth. Often seasonal migrations of animals are associated with movement to breeding grounds, sometimes many thousands of kilometers from their habitats. Animals that do not make such long journeys also choose their nesting territory in advance, and many of them carefully guard it and prepare shelters - nests, burrows, dens, adapted for future offspring.

A lot of parental worries are associated with feeding their offspring.

For most insects, caring for their offspring is simple. It is enough for the female to lay her eggs in a place where her larvae would find suitable food, for example, the larvae of the cabbage white butterfly - cabbage. But some insects specially prepare shelter and food for their offspring, for example, honey collectors - wasps and bees. And hunting wasps provide their larvae with crickets and grasshoppers. Before laying an egg, the sphex wasp injects poison into the nerve ganglia of its victim, so that it remains motionless but alive and serves as a supply of fresh food for the larva during the entire period of its development. In dung beetles, not only females, but also males participate in the preparation of food for their offspring - dung balls.

In many birds, the chicks hatch completely helpless and require frequent and regular feeding, some insectivorous birds feed offspring up to 200 times a day! Sometimes parents (jays, nutcrackers, etc.) store food for future chicks in the fall. The offspring of brood birds - chickens, ducks, geese, etc. - are born independent, able to swim, walk, and peck. Parents can only take them to food, water, protect them from enemies, and warm them (see Imprinting).

Female mammals feed their young with milk until they are able to eat other foods. In some animals this period lasts several weeks, in others it lasts longer, and in great apes- some years. Gradually, parents begin to accustom their children to adult food - they show them edible plants and teach them to hunt.

Many animals protect their offspring from enemies. In birds, colonial nesting serves this purpose, but solitary nesting birds can also unite to drive away predators from their nests. For example, if a cat or even a person tries to climb a tree where there is a crow’s nest, 10-15 birds flock to him and attack the troublemaker with screams.

Most mammals are more excitable than usual when raising their young. Many large wild mammals attack people precisely when they threaten their cubs or are close to them. The moose does not allow anyone, including other moose, to see the cub.

In many mammals and birds, the young stay with their parents for a long time, acquiring the skills necessary for life through imitation. This is the period of raising offspring. Parents teach their cubs to choose and find food, water and even medicinal plants, as well as shelter for sleeping or in case of bad weather. These forms of parental care are especially developed in mammals with a long life span. In elephants and some apes, adolescence lasts up to 8-10 years. Not only parents, but also almost all adult members of the group take part in raising their offspring. Older brothers, and especially sisters, or simply females who do not have this moment their own offspring, look after the cub, help feed it, look after it, play with it. If the mother dies, they usually adopt the orphaned cub. This collective form of caring for offspring significantly increases the chances of their survival.

The highest development of caring for offspring is in humans. He not only takes care of the children’s livelihoods, but also educates them, passes on to them his life experience and knowledge accumulated in history.

We are all accustomed to seeing a mother with a stroller, or with a child in her arms. In each country, children are carried differently: in the hands, in a special backpack - a “kangaroo”, in a cradle, simply in a cloth over the shoulders, or on the chest - a “sling”, on the shoulders (typical for the father). How do animals carry their babies? wildlife?
After birth, animals necessarily have a certain need to transfer their still completely helpless offspring somewhere. Monkeys, for example, have a fairly developed grasping reflex, so from birth they cling to their mother’s fur with their hands, hanging securely. At the same time, the mother can calmly climb and even jump on trees without causing trouble for the baby. During this time, kids manage to learn all the intricacies of getting food, getting rid of enemies, learning social laws life. Opossums are even more superior to monkeys; they have not one, but several cubs that cling to the mother from all sides, holding on to the fur, and she does not lose anyone.
About Australian kangaroos Everyone knows that they are carried in a special pouch, where the miniature baby, the size of a large bean, grows to normal size. At first the baby hangs on the nipple, sucking tightly, over time it begins to look like it is out of the bag, and only later jumps out. That is, kangaroo pups up to two years old can be in the mother’s “pocket”, and there are cases when the pouch can contain 1-2 summer child and a newly born baby hanging on the nipple.
Little hippos calmly “ride” in the water on their mother’s back. Elephants, although quite rarely, lift their children on their tusks and carry them to another place.
Mice and shrews save their numerous offspring by placing them in the form of a “train”: one baby grabs the mother’s fur above the tail with its teeth, the second takes the third, the next, and so on until the last. This way the whole family moves together. Rats are even better adapted to changes in their location: if the pups are more or less mature, they walk one after another, holding their tails, but if the children are very tiny, they transport them on their tail, stringing them together like beads.
Crocodiles, having waited for the hatching of their offspring, who call out from the sand, help them get out, tear up the sand and carry them into the water in their terrible mouth, practically between their teeth. And not a single child suffers from this. Some amphibians can also carry eggs, tadpoles and small frogs on their backs.
Interesting stories Naturalists report about turtles: the offspring of crocodiles and turtles are hatched in the same conditions, their eggs are laid in the sand and the babies hatch in the same way. Therefore, crocodiles can carry turtles along with their babies, while suppressing their cruelty and aggression, that is, in this situation, the maternal instinct dominates.
Transportation in the teeth is the most common method in many animals. Watching the animals, you can clearly see that they take the babies precisely by the withers, which is a rather vulnerable place. Parents can tightly squeeze the skin with their teeth, but never cause any harm, injury or mutilation. If you look closely at your pets - cats and dogs - you can often see this. Cats are generally excellent mothers. They feed their kittens with breast milk for quite a long time until the baby grows up and is able to feed on more adult food on his own. In order for the kitten to receive enough vitamins and energy, it is necessary to choose high-quality food. The best option Royal Canin food for cats, and your kitten will always be energetic, cheerful and healthy.
The witch-mother does not spoil her baby with carrying; more often the cub runs after the adults, rolls over in a ball, overcoming obstacles, but when real danger or obstacle threatens, the mother takes it in her teeth and carries it to a safe place. There are cases that even a hedgehog in its teeth carries babies to a dry place if their hole is flooded with water.
Wolves, sensing danger, quickly, with feverish speed, carry their puppies in their teeth to an emergency hole. But during the course of evolution, a different idea about wolves developed: hunters report that a she-wolf will not even give a voice, and not that she will rush at people who take her wolf cubs into a bag. They are too afraid of humans.
Hoofed animals travel long distances with children, holding them between their bodies, feeling their sides next to them. Moose become too aggressive when people approach them while the baby is still nearby on rather thin, unstable legs. In elephants, although they look large, children are completely useless; even their personal trunk gets in the way, so it’s safer to be at the mother’s side. Often the baby hides under the belly of adult elephants, and they support them with their strong trunks if necessary.
They write about the interesting relatives of our pigs - warthogs - that they instill in their babies the ability to wriggle out even from birth: having large fangs, in a cramped hole the mother never worries about not injuring the children with them, they themselves must be able to dodge danger, therefore the one who survived will be able to live on. According to statistics, in the wild the mortality rate of offspring is quite high. But, having learned the wisdom of survival from childhood, the animal has a chance to live as long as it is given.
Some birds can carry not only chicks, but also eggs in their beaks. Some are carried under the wings. Waterfowl “ride” the babies on their backs, since immediately after hatching they are ready for life: they dry off and set off. It’s a strange sight to see how the ducklings run after the duck right through the water, although they have very little strength. But when fatigue sets in, they climb onto their backs and hide in their mother’s feathers. The same can be observed in swans. On their mother's back they not only rest and warm themselves, but also feel safe. Not every predator wants to get to birds swimming in the middle of a pond with chicks on their backs. On land, swans can also fight back; the blows of their wings are quite strong and can even kill a fox.
Incredibly, some birds carry their babies in their paws. For example, the wood sandpiper does this in this way. In case of danger, he grabs the chicks in his paws and flies away from it, even making zigzag movements in flight. And black grouse and wood grouse use the necessary signal to force the chicks to hide or move unnoticed towards the mother.
Scientists believe that a chick that has fallen out of the nest is of little concern to its parents. Heron watching is proof. When a heron chick, staggering in a nest above the water, suddenly falls, the mother does not pick it up, although having a long beak this is quite easy to do, apparently they believe that “what falls, is lost.” But ornithologists think differently: this natural selection If there is no tenacity, then it is not entirely viable.
Unlike herons, almost all birds and other animals, risking their lives, try to save their offspring at any cost: they distract them from predators, make several nests, one of which is false, pretend to be sick and wounded, grab them in the mouth, make a terrible noise and uproar. . After all, caring for offspring is one of the main concerns in life.
Of course, for some groups of organisms, care for offspring does not exist. Firstly, in fish, since the amount of reproductive material in them is quite large, and their genus has flourished for millions of years. Although some of them have guardianship:
- in salmon, which lays eggs in favorable conditions, migrating to spawning sites over considerable distances, after which it dies, fertilizing the environment for the fry;
- the stickleback fish lays few eggs, about 50-70, making a plant nest at the bottom of the reservoir, and after the babies appear, it protects it from enemies;
- The seahorse hides its young in a pouch on its belly.
So, in the multifaceted animal world, a mother is ready to take risks and sacrifice her life for the sake of her offspring. This is the most important law of nature.

why were they preserved? various shapes caring for the offspring if all of them are not as efficient as possible?

Answers:

This is how nature works. These behaviors are regulated primarily by hormones secreted by the pituitary gland and ovary. In order for a species to continue to exist, each generation must leave behind offspring capable of reproduction. Most invertebrates and fish do not care for their offspring. They simply lay out thousands of eggs, only some of them produce young, and an even smaller number grow and reproduce. A more reliable way to continue the race is to provide them with food, protect them from predators, and even teach them some skills after the birth of a limited number of cubs. Many animals show care for their offspring in different forms. Most of them are endowed with special parental instincts, but in highly organized animals, individually acquired experience is also important.