Rabbits sometimes kill some of their own children and experts now claim that this is possible because it allows them to save and feed more of their babies in the longer term.
In nature it is known that many animals – including rabbits, chickens and fish – suddenly decide to eat or abandon their young.
But never before have scientists found evidence of those pursuing this for the perceived greater good of their surviving brothers and sisters.
Researchers from the University of Oxford have discovered that eating or leaving young children can reduce the pressure by accidentally having too many offspring – especially in animals that usually have large litters.
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Sometimes rabbits and chickens in nature decide to eat eggs on their respective pups and some researchers believe it might be for the improvement of the nest as a whole (stock photo)
Such overpopulation can lead to a scarcity of resources or a greater risk of disease.
This can therefore have a negative impact on entire animal families and populations – forcing parents to sacrifice part of their young for the needs of many.
The eating and abandoning of offspring has been observed in various species – including birds, fish, insects, mammals and spiders.
The reason behind the particularly counterintuitive approach to parenting has been heavily discussed.
Scientists had previously suggested that eating someone's children may be a result of parental hunger, or possibly a form of quality control.
In the new study, researchers from the University of Oxford and the University of Tennessee in Chattanooga focused on egg-laying animals that do filicide.
For egg layers, overcrowding – or & # 39; offspring density & # 39; – are a major problem, explains author and biologist Hope Klug of the University of Tennessee.
& # 39; Common egg laying is common in a series of fish, insects, reptiles and amphibians, & # 39; said Professor Klug.
& # 39; This makes it easier to protect, clean, incubate and feed the eggs – but it can also promote disease transmission and competition for food and oxygen. & # 39;
Due to these negative factors, the density of offspring can influence the chances of survival.
And for some species, having too many offspring results in the fact that some eggs are abandoned or eaten by their parents.
For example, Professor Klug explains that under certain damselfish & # 39; fathers more often ate eggs under low oxygen conditions. & # 39;
& # 39; Such cases have led to the hypothesis that eating or leaving offspring can be an adaptation to improve the overall survival of offspring by reducing their density. & # 39;
To test this hypothesis, the research team – led by lead author Mackenzie Davenport of the University of Tennessee – created a mechanical model to investigate the impact of various parental behaviors.
& # 39; The model introduced an imaginary individual with a mutation for childish cannibalism or offspring left in a population of generic egg-laying animals & # 39 ;, Dr. Davenport explains.
Scientists had previously suggested that eating someone's young, for example in chickens, may be the result of parental hunger, or possibly a form of quality control (stock photo)
The researchers discovered that if parents were given beneficial extra energy by eating in their spawn, the cannibalism gene would spread throughout the population.
In addition, the models suggest that when the egg-laying density results in an increase in offspring mortality, both leaving and eating their eggs becomes a wise strategy for parents.
This is because sacrificing a few eggs can lead to more offspring generally surviving, which is beneficial both for the parents themselves and for the wider population.
& # 39; Under these conditions, the mutants were able to surpass and replace the generic population, & # 39; Dr. reported Davenport.
The researchers discovered that this remained the case even when the cannibalistic parents received a small or no energy bonus from eating their children, or if the model assumed that abandoned offspring would die.
& # 39; Our findings suggest that, surprisingly, childish cannibalism and rejection of offspring can function as forms of parental care by increasing overall offspring survival, & # 39; concluded Dr. Davenport.
The full findings of the study were published in the journal Frontiers in Ecology and Evolution.
WHY DO ANIMALS INFANTICIDE WORK?
Infanticide is the act by which a child is killed and can be performed by a parent or another adult.
It is common with many species of animals and can be caused by hunger, elimination of competition or as a token of power.
In most cases it is caused by a serious emotional disorder of a mother or a new dominant figure in a social group that perpetuates their authority.
Maternal child murder
Maternal infanticide describes a mother who kills their offspring.
Many examples are recorded in nature, often when the mental state of a mother has decreased and she then takes the life of her newborn child.
It has been observed in both pigs and rabbits.
Female child murder
The killing of young animals by other females is a phenomenon that is often observed in large social groups.
In groups where there are many women for a few men, the sexual attention of the men may be limited.
In these cases, it is known that the females kill the offspring of other females to increase their chances of producing their own young.
This comes from a scientific term & # 39; reproductive fitness & # 39 ;, in which the success of an individual is measured by the amount of genes it passes on to the next generation.
To be more successful and to improve their condition, they prefer to have children and killing someone else's descendants can make this happen.
This is more common when food is scarce and has been observed in chimpanzees.
Male child murder
Male infanticide is the most common and well-documented form of the phenomenon.
This condition is often used in mammals and intelligent animals and is used both as a token of power and to bring women earlier in the season.
Prevalent in lion Prides, there is usually one adult lion who is the alpha in one pride and controls several women.
This alpha position can change ownership when a younger, larger and more masculine male removes the old male from the group.
In this case there will probably be many young animals in the sheepfold.
When the new male takes over, his first priority is to confirm his authority and ensure his own reproductive success.
The most effective way to do this is to clear all young people.
In addition to removing young pigeons that are not his own, he brings the females earlier in the season, allowing him to father his own offspring faster.
It has been observed in mammalian species ranging from dolphins to lions.
Researchers have also seen that a 32-year-old male killer whale killed a newborn.
The male killer whale was helped by his 46-year-old mother – who played an important role in the attack, scientists say.
In addition, she has effectively helped to pass on her pedigree as long as her son was successful in breeding the animal that lost her calf, researchers believe.