A couple of books for those interested in beaver management!
This week we have been largely focused on what characteristics that defines a species as invasive – or rather, of invasive potential!
As most of us know, there is widespread alarm that human encroachment upon animal habitat and climate change may have averse effects upon global biodiversity – but how many know of that invasive species are considered an even higher threat at present by many conservationists? Or in some cases, even a threat to us?
There’s no shortage of examples of where species have drastically changed their environment, certainly where humans have introduced non-native species:
- Exotic fish introduced by sporting associations have been known in many cases to wreak havoc across the local ecosystem,
- Some invasive species carry parasites or zoonoses with them which can be a threat to humans and other species (i.e. fox tapeworm)
- Novel plants can outcompete native species at the very least on a local scale,
- Organisms that have travelled with ballast water in boats can find themselves released in a very welcoming environment
- Animals released to control other species may turn out to be far more successful than intended (i.e. Cane toads in Australia)
Or indeed even the reintroduction of certain species. Beavers, for example, are a premier example of successful reintroduction of native fauna that had been driven to extinction by unmanaged shooting. This may come with unexpected benefits, as beavers are what we call an ecosystem engineer – that is, they change their environment to their benefit!
Most of us know that beavers can build dams. The resultant flooding of an area can lead to for example an increase of dead wood (substrate for many insects and also provides habitat for fish), but can also slow down the rate at which the water flows through the system. That means that sediment or maybe even pollutants have more time to settle.
Unfortunately, these dams can become major problems for the locals – they can cause harmful destruction of agricultural lands and loss of income, they “harvest” trees which could’ve been sold; beavers can also undermine infrastructure such as roads and cause them to collapse.
All this comes together nicely in wildlife management. After all, the job of wildlife managers is to regulate how people and wildlife coexist.