This week, I will be going on an expedition recce with Wild Intrigue to a Perthshire site, in the hope of studying European beavers. We’ve got loads of blogs to write and vlogs to film and I can’t wait to get back in the wild. I’ve loved my second year at uni and it’s been great to be so busy, but due to assignments and increasingly bad weather I’ve hardly been able to go on any walks to take photos.
So in preparation for my next exped, I wanted to find out a little more about the largest rodent in Europe, which I’m really hoping to photograph while we’re there. I didn’t know hardly anything about beavers, and due to their elusiveness it seems their lifestyle is largely a mystery.
Living by still or slow-flowing water with adjacent woodland, beavers are known as ‘ecosystem engineers’ for their river handiwork. By building their dams, they regulate the water level and alter its flow pattern, which ultimately reduces erosion, as well as providing an important store of water for plants and animals during droughts. By felling trees, beavers open up their forest habitat and create new, small-scale landscapes such as ponds and swamps.
Beavers were driven to extinction in Britain in the 16th century. For many years they were hunted for their valuable fur, but also for the secretions from a pair of musk glands beneath their tail, which the beavers use for marking their territories. The secretion (castorium), was sought after for traditional medicine and the manufacture of perfumes. Despite this persecution, beavers have since been successfully reintroduced to parts of Scotland and southern England.
Beavers have two layers of dense fur, a courser outer layer and a woolier under layer. Their hind feet are webbed and used to propel the body through water, while the front feet have opposable digits for gripping branches. Similar to crocodiles and hippopotami, the beaver’s sense organs are aligned in a row so that they can swim with their nostrils, eyes and ears raised above the water while keeping the rest of their body submerged.
A beaver’s tail is a multipurpose tool. Broad and covered with overlapping keratin scales, it’s used as a prop for balance when cutting trees, as a rudder during dives and an alarm signal when in distress, where the animal slaps it against the water. Fat reserves are stored in the tail and a counter-current arrangement of blood vessels enables an efficient heat exchange system, that can result in a 25% heat loss through the tail in summer and 2% in winter.
Entirely vegetarian, beavers are crepuscular, meaning they are mostly active at twilight. They can use their chisel-like incisors to gnaw through an 8cm wide tree in five minutes. In fact, they can carry on gnawing while submerged underwater by sealing the backs of their mouths with folds of skin. On dives they can close their nostrils and ears and cover their eyes with a nictitating (transparent) membrane.
So it turns out that beavers are fascinating creatures. Now that I’ve got myself acquainted with these industrious rodents, now I can only hope that I’ll get a glimpse of some this weekend.