Is it possible to prevent the sixth mass extinction and how to do it - says biologist Ivan Zatevakhin

On April 29-30, the event "Scientists against myths”, in which well-known experts will dispel stereotypes about life on Earth and in space.

One of the biologists invited for discussion is Ivan Zatevakhin. He was the editor-in-chief of Friend magazine, made several films about wildlife, participated in the operation to free killer whales, and now hosts the program Animal Dialogues.

Lifehacker talked to Ivan about sixth extinction and how to stop the extermination of animals in order to prevent the death of many species. Here's what we found out.

Why Mass Extinctions Happen

A collection of living things of different types, interconnected and interacting in the same habitat, forms an ecosystem. It remains more or less stable until global metamorphoses occur.

The fact is that in the history of the Earth there is a global

climate change conditions. Thermoeras are replaced by cryoeras. In the time of the first, all the continents are brought together. The cryoera, in which we live, is characterized by the fragmentation of the land and the presence of polar caps.

This is a natural process. Continents float in a molten liquid, magma, like a fondue pot. The earth is spinning, and then they converge, then they diverge. This causes global changes in weather and climate, which in turn leads to the transformation of the vegetation cover. And after this - and to a sharp change in the fauna. That is, the whole ecosystem is involved.

In such a situation, some species die out, some evolve, change, adapting to new conditions.

For example, non-avian dinosaurs finally became extinct at the end of the Cretaceous period. And for 10 million years before that, there was a change in plant formations, physical and geographical conditions and the ecosystem as a whole.

Some scientists claim that, in addition, the dinosaurs were finished off by a fallen meteorite. And then they were slowly replaced by mammals, which together with them quite normally existed in the form of nocturnal hunter animals. They simply did not occupy prominent positions in ecosystems, they did not dominate.

In addition to the mass extinction, there were others - less known, but much more global. All of them were associated, on the one hand, with powerful environmental changes, and on the other hand, with unforeseen catastrophes. What is primary and what is secondary - paleontologists cannot yet agree.

One thing is for sure: evolution, the change of species is a normal process that occurs constantly. Without it, life as we know it is simply impossible.

Has the sixth extinction begun and is man involved?

The term "sixth mass extinction" today is not recognized by everyone. But the fact that a person catastrophically affects the ecosystem is a fact.

For all continents except Africa, Homo sapience is an invasive species. When he enters an ecosystem in which he has never lived, then how worm, "infects" it, breaks it for itself.

And although, as I said, the change of species is a natural process, throughout history, man in many ways "helped" to finish off the fauna. For example, some scientists believe that the first settlers of Homo sapiens about 50 thousand years ago quickly destroyed large animals that were dying out in Australia by that time.

Once upon a time, the megafauna of this continent consisted of giant wombats, the size of a hippopotamus, large kangaroos... But they all disappeared with the arrival of man.

In addition to the fact that people themselves migrated to different continents, they also brought other animals with them.

For example, Europeans brought rabbits to Australia, whose breeding rate is legendary. Trying to get rid of their dominance, they delivered foxes. However, it turned out that it was all the easier to hunt some marsupials that did not have any adaptive behavioral mechanisms to resist placental predators. Their foxes began to exterminate.

Cats that moved to New Zealand with a human also turned out to be a dangerous invasive species. The fact is that there they began to hunt local birds, many of which were flightless, which made them helpless in front of predators.

Man was not an invasive species only in Africa, because it was there that he evolved, and the local fauna adapted to him. Therefore, before the arrival of people from firearms on this continent with a natural balance, everything was more or less normal.

The extinction that we are seeing there now is happening for the same reasons as in other areas of our planet. Anthropogenic pressure is increasing - the impact of human economic activity on nature. He builds cities, sows fields in territories where savannah used to be, cuts down forests, including on watersheds, which is absolutely impossible to do.

Man is the main cause of ecosystem change today. However, I would use the term “sixth mass extinction” with caution, because this is something irrevocable, and we still have a chance to correct something.

After all, in those places where people leave, the ecosystem is quickly restored. This is noticeable where there are good nature reserves.

Instead of "extinction" I would use the term "extermination". Such human impact on nature can be compared with a super pandemic, which affects all animals on the planet.

Of course, extermination lead to extinctionif we don't stop. The modern fauna will change, something else will appear on its ruins.

I can already see biological futurists saying that the sixth mass extinction will bring rats, birds, bugs to the top. And it will be another ecosystem where a person is unlikely to find a place.

How to stop the extermination of species

This requires a whole range of measures. I'll tell you about them in order.

1. Create biosphere reserves

There are animal species that can be conditionally called "castle" ones, since the health of the ecosystem is largely dependent on them. These are, as a rule, large predators or landscape-forming animals like elephants.

For example, a whale mixes water masses, bringing so-called nutrients to the surface, eats fish and produces a huge amount of fertilizer, on which small algae grow. And they are light our planet.

If people had not exterminated a huge number of whales (you can’t even imagine how many!), then perhaps we would not have observed any greenhouse effect.

Or, for example, elephants are a landscape-forming species. They break bushes, thanks to which the savannah is not overgrown with bush. If this happened, then large ungulates - for example, zebras, wildebeest - would have no space left for grazing.

Another famous example is the wolves in Yellowstone.

Once these predators were exterminated there and the ecosystem was disturbed: deer ate the vegetation. But as soon as the wolves were returned, the landscape acquired its former features.

Wolves drove deer from the shores of reservoirs to the watersheds, reducing the number of these herbivores. And the vegetation that they had eaten away in the valleys became abundant again.

Thanks to this, the population of beavers flourished, which began to build dams. Otters, birds and amphibians have returned to the ponds they created. The flora, in which there were more berries, attracted bears. At the same time, the number of coyotes, which exterminated a variety of rodents, decreased. The latter became more - the birds of prey returned, badgers, weasels and foxes.

Such “castle” views are a must-see. Their well-being is an indicator of the health of the ecosystem. Therefore, to protect nature, it is worth creating reserves, the most effective of which are biospheric ones. Speaking in a dry language, these are territories created to preserve ecosystems and the gene pool of the region, study and monitor the natural environment in it and in areas adjacent to it.

An example is the Commander Marine Biosphere Reserve, which occupies the water area and part of the territory of the islands. Since it was established in 1993, killer whales, humpback and bottlenose whales have returned to the area, and the number of sea otters has almost recovered. Than such nature reserves will be more the better.

2. Control the pollution of the planet

This is one of the most important rules. It is necessary to control toxic emissions, recycle garbage, and prevent plastic from entering the environment. This should involve both large corporations and ordinary people.

3. Limit expansion of human habitat

It is necessary to stop thoughtless construction, including on the site of deforestation, as well as the creation of polluting enterprises in areas vulnerable to nature.

Reasonable environmental legislation will help here, regulating the penetration of humans into the natural habitat of animals. For example, in Australia and New Zealand, the most stringent rules have been established that regulate that people live where people live, and animals live where animals live.

4. Develop good zoos

When the zoo looks like a menagerie, it's a horror: the area for moving is limited, animals sit in cramped cages and receive poor care. It is easy to check how they feel in such conditions: they can measure the level of cortisol, and it will be very high.

Therefore, the zoo should have spacious enclosures, where they regularly work with animals, enrich their environment by changing the landscape of the territory, inventing puzzles for them to get food. Then they will not suffer from routine and lack of new information.

Also good practice is wind training. This is the best thing you can think of for animals, including those kept alone - without partners. During the training, animals are taught certain actions: for example, to approach the fence of the enclosure, give a paw or open their mouths for inspection.

At the same time, a keeper, a person who cares for animals, not only diagnoses the condition of the wards, but also communicates with them. In layman's terms, this gives them an additional motive, and the need for communication is realized in social species.

In addition, I know several cases when representatives of a certain species are practically gone in the natural environment, but they were preserved in the zoo.

For example, some time ago, with the official permission of one of the countries of Southeast Asia, Russian scientists caught several snakes. And then the forest in which this species lived was cut down. In the end now snakes remained only in the zoo nursery of the Moscow Zoo.

Gerald Durrell said: "Zoos are the repository of the gene pool." Thanks to them, it is possible to reintroduce animals - that is, to return them later to their natural environment, although this is difficult and expensive.

It is important that not all species can be relocated to the wild from artificially created conditions. For example, marine mammals that were born in a dolphinarium and did not learn how to hunt and communicate with their own kind will not survive in the natural environment. Experiments on the return of killer whales to ocean were successful only in cases where the animals remained in a semi-wild state.

That is why the trapping of marine mammals is prohibited in Russia - this causes obvious and irreparable damage to wildlife.

5. Listen to experts, not activists

There are energetic, but poorly educated people who very often try to bring their ideas to life, and as a result they only make things worse. I'm talking about zooradicals now.

And they hurt nature much more than some chemical factories. Due to the lack of education, the decisions they push through are most often to the detriment of animals.

For example, animal radicals have banned performances with killer whales in large American dolphinariums. Why is that bad? Because these killer whales cannot be released - as I said before, they will die in the wild. And the only entertainment they had was many hours of communication with the coach. And now, when funding for dolphinariums has stopped, they just sit and fade away in small pools.

Experts should be in charge of conservation. Indeed, in order to develop the right actions, it is necessary to take into account many factors, which only people with special education can do.

Scientists must make optimal decisions, the public - make a fuss. And in order for both of them to listen to each other, a well-functioning system of communication in this area is needed.