How to control invasive species? Come on, let me tell you a story about witty humans and a hapless island.
There is an island in the southeast of Australia called Macquarie Island. The area is 128 square kilometers. It is slightly larger than the east and west urban areas of Beijing combined.
This island used to be a good place. Rich in many birds including kiwi.
Oh, you may not know why they are called kiwis, just look at this one:
One day in 1810, the crew of the Endurance discovered the island, along with a large number of seals of all kinds.
The environment here is not very suitable for human habitation, so only seal hunters visit regularly. But they brought mice. Mice love it here (eggs and chicks). Mice are also very good at giving birth to young mice.
Before long, Macquarie Island had more rats and fewer birds.
The hunter finds that his hut is always getting mice, which is very annoying. Around 1820, a witty hunter came up with the genius idea of using cats to control mice.
Cats love to eat mice. But cats also love to eat birds and are good at giving birth to kittens.
Before long, the island had more cats, slightly fewer mice, and fewer birds.
In 1870, a hunter named William Elder missed the rabbit meat in his hometown, so he wisely brought a few rabbits to the island.
Rabbit ran away.
Rabbits like to eat grass. Rabbits are also eaten by cats, but are especially good at giving birth to bunnies. The grass eaten leaves the land barren, the ground is eroded, and bird nests (especially penguin nests) on the ground are heavily damaged.
Before long, there were more cats, many rabbits, still many mice, and fewer birds on the island.
In 1880, ingenious humans tried to control rabbits and brought ferrets to New Zealand and Macquarie Island.
Ferrets eat rabbits, but there are seabirds and seabird eggs lying on the ground everywhere.
It wasn’t long before the island had ferrets, cats, rabbits, mice and fewer birds.
At the same time, astute humans discovered that places like New Zealand were suitable for keeping possums as a source of fur and meat.
Possums have no natural enemies, and cats don’t care.
So far, the island has possums, ferrets, cats, rabbits, mice and very few birds.
Still a lot by human standards.
Around 1880, the introduction of rabbits led to the proliferation of cats, and many cats began to develop new food resources after the baby boom, such as Macquarie parrots.
This is the Macquarie’s close relative in New Zealand, not its own, because the Macquarie became extinct in 1891.
Whaling and sealing ceased in 1919. In 1933, Macquarie Island became a protected area.
At this time, Australian scientists were studying how to eliminate rabbits on the mainland, and wise humans decided to copy them on the island.
First of all, they introduced rabbit fleas in 1968, but it didn’t work, so in 1978 they used rabbit myxoma virus by hand.
The good news is that the number of rabbits has dropped from 130,000 to 10,000.
The bad news is that the remaining 10,000 are immune.
The ugly news is that without the rabbits, the island’s 500 cats know what to do.
As a result, 60,000 birds end up in cats every year. There are fewer rabbits and fewer birds on the island.
In 1985, the official cat hunting operation of the Australian government began. In 1997, a large-scale and comprehensive extermination of cats on the island began. A total of 2,450 cats were captured on the island during the 20 years before and after, most of which were trapped in pits and then humanely destroyed. At the end of the operation, a team of specially trained dogs swept the entire island looking for fish that slipped through the net.
By June 2000, the last cat on the island no longer existed.
But without the cat, the remaining 10,000 rabbits on the island began to expand like crazy.
Dig up the vegetation.
And these rabbits are immune to rabbit myxoma. Within 10 years, the number of rabbits had recovered to nearly 100,000.
In 2007, the Australian government finally realized that all invasive species must be completely eliminated at the same time, and none of them should be left. They went on a big campaign to wipe out all the rabbits, rats, and all other invasive species on the island.
Smoky rabbit hole.
Harrier.
Poison bait.
By the way, the budget for this project is 24 million Australian dollars (about 150 million RMB).
In 2011, many birds were found eating the carcasses of poisoned rabbits and mice. 2,190 birds died from the poison in one year.
Much better than before, right.
In 2013, the Australian government announced that no rodents or rabbits had been found in the past year. Populations of wild birds appear to have begun to recover.
To this end, the Australian government issued a set of stamps to commemorate the dogs in the battle on Macquarie Island. Well, they are quite cute.
Well, witty humans seem to have finally made it this time.
But anyway, this is a silly story about Macquarie Island and witty humans.
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