Where the beavers are…
You are kayaking down the river early in the morning. The sun is just rising and the mist hangs over the water. It’s the best time of day to see wildlife, and you’ve already seen a kingfisher zooming past and the local grey wagtails building their nest. You know that otters are a possibility, but something even more exciting is the reason why you’re here. Their tell-tale signs litter the riverbanks: gnawed bark, trails going up the riverbank, entire branches felled into the water. After 400 years, beavers are back.
You stop your kayak and float downstream pretending to be a log so that the beavers won’t notice you. As you float past their lodge, you hear a massive splash and glimpse a beaver darting under the water. You hang around for an hour hoping that the beaver will resurface and you’ll be rewarded with a close view of it browsing on the willows, but no luck – the sun is hitting the river, the paddleboarders are out, and the beavers have gone into their lodge for the day.
The beavers may be cocooned in their lodge, but evidence of their presence is still abundant. Gnawing where they have stripped the bark off of trees, felled willow trees resprouting lush green shoots, muddy paths up the riverbank to where the beavers graze in the fields above. Even entire trees have fallen into the river and been stripped bare up to beaver height.
In a small, but increasing number of places where beavers are back, the signs they leave behind allow us to survey their distribution.
Beavers tend to disperse in their second or third year and usually move downstream to occupy the deepest water first. On these large rivers, the best way to survey is by kayak, so that you can see both riverbanks from the water level. Where beavers are resident and breeding, the evidence can be overwhelming: felled trees with the bark stripped off, lodges along the riverbanks, and footprints on the mud where beavers have been feeding.
Where they have built dams in small streams, the entire riparian zone is transformed – and there is no doubt that beavers are present.
However, when beavers are just starting to colonise a river, they can be surprisingly hard to detect. If there is plenty of willow close to water level, they don’t bother felling entire trees, so what you’re looking for is gnawed branches often about the width of your arm, but some sometimes as small as a finger.
When these branches are so tiny, how can you tell that a branch has been gnawed by a beaver rather than cut by a human or simply snapped off? There is a simple trick: run your finger over the cut, and on a beaver-gnawed branch you can feel the curves of the tooth marks.
Sometimes these tiny tooth marks are the only evidence you will see of beavers, but knowing that they are there, and that their populations will only grow, makes a kayak down the river so much more exciting.
As well as the magic of being in beaver territory, the evidence they leave behind from their feeding and engineering activities is useful for monitoring their populations. Estimating the exact number of beavers in a river catchment is tricky, and is not by itself particularly useful anyway. Beavers are exciting because they modify their environments, so what matters most is the extent to which they are transforming their surroundings. As Beaver Trust’s Community Projects Officer, it’s important to know where beavers are active within a catchment both to understand their ecological impacts and so that we know where any management of problems may be required. Understanding where beavers are spreading across the country and creating effective beaver management systems is also important to our development of an English Beaver Strategy. Beaver Trust is currently in conversation with the Government and we hope to have an update on the Strategy later this summer.
As beavers become more widespread across an increasing number of river catchments in Britain, there will be ever more opportunities to spend days searching for the elusive signs of these amazing creatures.
Josh Harris: Beaver Trust Community Projects Officer
With a background in Zoology and an eye for photography, Josh is an invaluable member of the Restoration Team helping to build a real-time picture of beaver populations in England. You can often find him on the water in his kayak, looking for signs of beavers in the rivers.
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© Josh Harris 2021.