How do animals like beavers and otters stay clean underwater (and benefit their environment at the same time)

A British beaver living out its life on the the river Otter in Devon

Anyone who has removed a branch or similar from a pond, will remember the incredible quantity of weed that will have wrapped around it. Any surface which lies underwater, tends to accumulate variety of things which makes it “grimy”. From dirt to algae and even bacteria, the process is called fouling.

However, animals like otters and beavers do not have to spend large amounts of time removing these substances from their fur – Why? This ability comes in part from the fur itself, where each hair can bend and flex as the animal moves, and a recent study showed that this ability to move allows the accumulation of dirt to be less than half of that when the hair is held steady at both ends (or for instance in hair that does not sway). This is a big issue in places such as boat, and people are working on ways to stop this.

It is fascinating the way that so many human processes take their inspiration from the natural world.

Beaver dams create barriers which allow all these bad substances to be removed. Dams block large quantities of soil, manure, slurry and fertilisers from rivers and streams, The stationary water allows substances like fertilizers and other chemical substances to sink to the bottom and be removed from the river ecosystem. Both the European beaver and the American beaver have the same impact on their water environment. While otters do not have the same dam making ability, they do have cleaning impacts on their environments as well.

It is well known, that while otters and beavers are often not the first species to return after a river is polluted, they can accelerate the process.

Germany – Alps

The German Alps

The German alps, like many parts of Europe, exterminated all their predators by the middle of the twentieth century. Due to its position, and an increasing acceptance of the science of how the environment there has been a less agressive reaction to various predators returning.

It should be noted that despite it being more than 30 years since east and west Germany merged to once again form one country, in terms of wildlife they still feel like very different places. West Germany exterminated most of its big predators, where as western Germany did not. The majority of the wolves do still live in areas that were under eastern German control.

It is true that bears have not yet made Germany their home. A bear entered Germany back in 2006, and while the government and local population were initially pleased, after he killed a few livestock a few attempts were made to catch him so he could be moved elsewhere. When this failed the decision was made to kill him – it should be noted, that a significant part of the population was against this decision. The hunt took over a month, with a significant outlay spent on expert hunters bought in from Finland. In the end though this failed and he was shot by a local hunter (much against the locals wishes).

In October of 2019, another bear wandered over the border again. Bavaria authorities behaved in a far better way on this occasion, and while careful note was made of where he was and what he was doing, he was left largely alone. It is unsure what happened to him, but it is clear that while without human intervention, bears are likely to eventually return to the wild in Germany, they have not yet.

A view of the German Alps

Wolves are different. There is some debate over how many wolves live in Germany at this point. It is thought that they first returned in 1998, and have been doing relatively well since. There is thought to be a little over 100 wolf packs, but a significant dispute as to an accurate number of individual animals. The government claims numbers of 400 while hunting groups claim the real figure is as high as 1300 (hunting organisations almost always over estimate, as this gives them a higher quota to keep the population in check). It is also common for hunting organisations to be paid by farming organisations, in order to keep livestock predation under control, thus giving a further incentive to over estimate, allowing them to kill more animals.

It is probably more likely that the true number lies somewhere between the estimates, perhaps around 600 individual members. They have a permanent presence in Brandenburg, Saxony and lower Saxony.

Lynx are still found widely throughout Germany, though as an incredibly shy species a sighting should be considered very lucky.

European wild cats also still roam widely throughout germany.

See Animals Wild