(This was originally published on my blog at another site, Feb 2018.
They look so cute and cuddly. Their species “spokes-animal” has been in story and film as a heroic champion, saving humans from evil cobras! It’s rikki-tikki-tavi the valiant mongoose, of course
On the flip side of the coin, this furry little creature is blamed for the decline/extinction of the bar-winged rail, possible extinction of the Jamaica petrel (critically endangered and possibly extinct), the decline of hawksbill turtles (critically endangered), pink pigeon (endangered), Amami rabbit (endangered) and many other birds, reptiles and mammals. It also carries rabies and other human diseases.
This is Invasive Species Week and I wanted to send out a reminder because many invasive species are introduced to non-native environments deliberately.
Typically, the little mongoose was not such a villain until it was taken to places where it wasn’t a native, but an invasive species. It was brought to Hawaii in the 1800s to control the rat population. It failed because rats come out at night and mongooses hunt during the day. One (I guess) positive - they help keep the population of wild chickens down, except on the island of Kauai where they were not introduced. They were introduced, though, to several Caribbean islands with similar results. In case you’re wondering, it isn’t so much that they eat birds that they cause havoc with bird populations. They like eggs.
In Hawaii, we have another invasive species which is not so cute: the cane toad. I hear it is a much bigger problem in Australia. Two things make them a problem. One, they excrete poison from their skin. Two, predators in their native habitat are immune but predators in introduced areas are not. I had a personal experience with one a few years ago. I saw my dog (around 25 lbs) about to grab a cane toad. I tried to stop him but he did it. He grabbed the toad and shook it once. Then he dropped, began to drool, and stumbled around a few minutes they laid down to rest. After several minutes he was up and fine. He did that two more times which I witnessed, each time with the same result. My guess is then, cane toads are more a threat to cats and smaller dogs. Of course, there is always a third problem when there are no natural predators. They lay lots of eggs.
Make cute, fuzzy creatures the destroyers of entire ecosystems - sounds like the evil plot in a dystopian novel. Here is another to join mongooses - the rabbit. Yes, even cute little Easter bunnies cause problems. Again in Australia, rabbits are a prominent pest. They were introduced in Victoria in the 1850’s as a familiar food for pioneers. Of course, some escaped and they spread; a single mama can have up to thirty offspring each year. The problem became so serious that in 1904 a “rabbit fence” was built to restrict further spread. Built in 1904 it stretched 1864 kilometers, 1139 miles! It didn’t work and in 1905 a second fence extended the original by another 1166 kilometers, 724 miles.
You might wonder how a rabbit can be a problem. As with many if not all invasive species, if there is no natural predator, they proliferate rapidly. They eat a lot so many native species of plants are endangered. Their heavy grazing and their burrowing increase soil erosion which can alter the natural environment and endanger many native plants and animals.
Just a quick note about a surprise to me. As a kid, I used to pull carp out of lakes and stock ponds all the time. Come to find out, they are an invasive species. They were introduced in the United States in the 1880s for sport fishing.
There are so many invasive plants and animals I would need to write a book to scratch the surface. Do a search and you will find plenty of info. Include your state or country or area in search to get specific info. There seems to be an agency to battle invasive species in every state and most countries.
I must say that while human intervention in the spread of plants and animals is often a royal screw-up, it is also often successful. For example, bovines in America, except for the native bison, are introduced animals. Wheat originally is native of Mesopotamia but is now worldwide. The Monterey pine was introduced to New Zealand and Australia from California and is now a timber crop.
It seems that most invasive or introduced species are here to stay. Million plus are spent annually to counter non-native plants and animals. It’s a losing battle because it is a bit of nature. Whether instigated by people or not, it has always happened and likely always will. I might be a better investment if agencies tasked with getting rid of introduced/invasive species were instead working to find a useful way to incorporate them in their new home. What do you think?
Here are some interesting general websites:
https://www.washingtonpost.com/news/energy-environment/wp/2015/02/23/like-most-invasive-species-pythons-are-in-the-u-s-to-stay/?utm_term=.96a49e19943c
http://www.businessinsider.com/invasive-species-cause-huge-problems-2016-3
http://www.mauijungalow.com/2014/04/mongoose-one-of-hawaiis-big-failures.html#.WpRHH6jwZPYinteresting videos of mongooses
