Can non-human animals kill other animals?

2022-07-16 0 By

If humans place certain animals where they shouldn’t be, they become invasive species, or species that cause ecological or economic damage to a non-native environment, according to live Science.Imagine looking up and seeing a dense mass of birds blocking out the sun.Passenger pigeons used to fly in groups of hundreds of millions or even billions, taking hours to pass overhead.Then we started shooting them.Audubon magazine said passenger pigeons were hunted on a large scale from the 19th century until they were extinct in 1914.These birds are the best example of how quickly and efficiently humans can wipe out even the most common species.But was it just us that wiped out other animals, or were there non-human animals as well?Some non-human animals may be responsible for the extinction of other animals, but humans are usually responsible.If humans put certain animals where they shouldn’t be, they become invasive species, which cause ecological or economic damage to non-native environments.Right now, for example, Burmese pythons from Asia are devouring anything that moves in the Florida Everglades.The Florida Museum of Natural History says the pythons were originally pets that escaped or were released.Species that are unable to identify or properly cope with new species in their environment are said to be “inexperienced”, or are said to suffer because of their “inexperience”.It’s not their fault.Animals are not evolutionarily capable of running away or protecting themselves from an alien species, and adaptive changes don’t happen overnight.Tim Blackburn, professor of invasive biology at University College London, UK, said: “The main way that alien species wipe out native species is by eating them, including introducing predators into areas where there wouldn’t have been predators before, or introducing new predators into an area.This gives them a natural advantage that allows them to eat up the native fauna that is inexperienced (animals of a particular area).”Blackburn’s example of an invasive species is the domestic cat.”They caused the extinction of dozens of bird species,” he said.One example is the Stephen Island wrens of New Zealand, which became extinct in 1895.Cats are the leading direct human cause of bird deaths in the United States and Canada, according to the American Bird Conservancy.In other words, American birds are more threatened by pet cats than they are by guns.It was man who brought hunting cats and pythons around the world.Anything they do after that is on us.But what happens when animals naturally migrate to new areas?Animals tend to naturally disperse to nearby areas where species are broadly similar and therefore react appropriately to each other, often without playing off unfairly, Blackburn said.Occasionally, plate movements force species to reshuffle the deck.The Great Migration between North and South America (about 10m to 10,000 years ago) is a striking example;Tectonic plates pushed North and South America together, and species from the two continents met across the Central American land bridge.Many new animals were introduced to South America, including carnivores such as bears and big cats;North America received species such as the sloth and a relative of the armadillo called the glyptodon.The diversity of animals that migrated from North America to South America was higher than the reverse, so there were more non-migrating animals in South America.A 2020 study published in the journal Proceedings of the National Academy of Sciences suggests this is due to an exceptionally high rate of mammal extinction in South America.In other words, in the exchange, more species in South America became extinct, and fewer were able to colonize North America.”Perhaps native South American mammals were more vulnerable to new predators,” said Juan Carrillo, a paleontologist at the University of Fribourg in Switzerland and lead author of the paper.Hunting by carnivores in North America is only one hypothesis for asymmetric exchange.”Sloths and glyptodons were probably big enough not to be eaten by these predators,” Carrillo told Live Science.That’s probably one of the reasons they were able to migrate northward, and we’ve found them in fossils from many parts of North America.”But while the impact of modern invasive species on extinctions is clear, the exchange paints a more complex picture.”It’s not just a moment in earth’s history, it actually took millions of years, and there were different stages,” Carrillo said.The mass extinction in South America occurred at a time of climate change, when the earth began to cool, which presumably also played a role.But is it still possible to assume that at least some prey species in South America were wiped out by a predator that came to North America?It’s possible, carrillo said, but it’s hard to separate the cause from other factors such as climate change.Animal traits were formed on an evolutionary battlefield, but that doesn’t mean carnivores evolved to dominate their prey.Carrillo points out that if a carnivore were to eat its prey to extinction, it would have nothing left to eat and would therefore die out.If a carnivore has multiple prey, it can theoretically wipe out a species and survive, but extinction usually involves multiple factors.Blackburn had not heard of an example of natural invasion: one species eating another to extinction.”Nature is extremely complex by nature and it takes a lot of work to tease apart the various processes that normally occur,” he said.Humans are clearly driving species to extinction through activities such as overhunting, habitat destruction and the introduction of invasive species.”The impact of these human activities is so large, that in itself is strong evidence that these processes are real and very different from the past,” Blackburn said.Source: Reference Information Network