Strange beasts in strange places
Sometimes animals turn up where they do not really belong and thrive in their new surroundings. Here are a few examples.
Beavers in the UK. In recent years beavers have not only appeared in the wild in the UK but are also thriving. UK is an island and even though beavers are excellent swimmers, they cannot swim across oceans. Many do not realise that historically beavers occurred naturally in the UK but were hunted to extinction. As part of rewilding programs beavers were reintroduced to sites across the UK and are doing well.
Hippos in Colombia. There are about 170 hippos living in the Magdalena River in Colombia. They descended from a handful of hippos from the private zoo on the estate of drug lord Pablo Escobar. Following Escobar’s death the zoo animals were removed, except for the hippos. They were deemed too dangerous to be moved. They were simply left, the thinking being that they would just die out. The resourceful hippos escaped into the nearby river and with no natural predators they have proliferated.
Camels in Australia. Camels came to Australia as draught animals and played a vital role in the opening up of the outback. With the coming of the railways and more reliable motor vehicles they were no longer needed. In many instances the Afghan cameleers simply released their camels into the wild. There are more than million camels in Australia, many more than in their Arabian homelands.
Brushtail possums in New Zealand. They were introduced to provide furs and quickly bred up in the wild. Forty years ago, the NZ population was 60-70 million but has fallen to 30 million, largely due to baiting.
Wallabies in the UK. There are populations of red-necked wallabies in Scotland and the Isle of Man and numerous sightings throughout England. The wallabies were introduced to the UK because they were ‘easy’ zoo animals. Presumably there have been escapees that have bred but they have not always been successful with a colony in Derbyshire becoming extinct in about 2009.
Bison in Poland. We think of bison as being North American animals. There have always been bison in Europe. They appear in early man’s cave paintings. While their numbers and range have dwindled over the millennia, they never became extinct in central Europe, with the largest remnant population being in Poland. Polish bison have been used across Europe in rewilding projects.
Northern Pacific seastar in Port Phillip Bay. It is too far for them to walk along the bottom of the ocean so they hitched a ride. Cargo ships need to be laden down. If they are empty, they float too high and can become quite unstable so they take on water as ballast. It is thought that starfish larvae came to Port Phillip Bay in ballast water which was then pumped into the Bay. They are voracious predators of shellfish and barnacles and can carpet the seabed.
All of these animals have changed their environments. The beavers and bison have been used to change environments in a positive way. Others have had negative impacts. Without natural predators they can breed to the point where they are stressing their environments. They often out compete or destroy native species. They reshape their new environments, often being quite destructive. They also have economic impacts.
