Beaver updates

Beavers maintain the ‘castoreum’ layer of their fur during grooming, and they have another adaptation to help with this – a specialized split nail ‘grooming claw’ on the second toe of each of their hind feet, which they use to remove dirt and comb oil into the hairs all over their bodies. 

Unfortunately, it was their fur that made them a target in the past that led to their extinction in the UK. A beaver’s fur was highly sought after by humans due to the amazing thickness and warmth it offers.  

Wild visitors

The wetland site is not only home to beavers, but a variety of other species which have increased since the beavers arrived, making use of the habitat they have created. We have spotted a fox regularly, who we think may have moved in, otters, and roe deer crossing the main beaver dam. We have also had some Canadian geese swimming serenely on the largest of the beaver ponds and spotted a brand-new resident – a mallard duckling. 

With the warm, dry spring weather the site has become a butterfly hotspot, and we have recorded brimstone, peacock and orange-tip butterflies.  

The orange-tip butterflies may be particularly happy in the beaver created wetland due to the numerous cuckoo flowers that have sprung up and gradually increased over the last few years as the damp habitat they thrive in has become larger due to the beaver's habitat modifications. The cuckoo flower is the food source of the orange-tip butterfly, and where they lay their eggs. We spotted some tiny bright orange dots underneath the flowers, which are orange-tip butterfly eggs. Once hatched the caterpillars will feed on the cuckoo flowers before they go on to become butterflies. We will be keeping an eye on the plants and will hopefully be able to show you some orange-tip caterpillars in the next few weeks.  

On the pond

Our rivers team headed out onto the main pond for a dinghy side view of the beaver lodge. We had a look around at the reeds and vegetation and got some great shots of the main beaver lodge from the water. The beavers do a great job of managing the reeds, by pulling them up and eating the roots. The reeds can dominate if not managed, and by doing this the beavers are carrying out a job that is often part of wetland habitat management for conservationists and land managers. The broad-leaved pond weed has risen to the surface and in the next few weeks will layer the surface of the water and come into flower in the summer months. Broad-leaved pond weed is great for providing shade to the water below and reducing the growth of algae. Its leaves also act as platforms for viewing, courting and mating for a variety of insects. Whilst out on the water the team secured a trail camera to a tree near to the lodge. We will hopefully share any footage we gather from the new camera in a few weeks' time.  

New beaver channels 

There has also been some recent channeling carried out by the beavers. Creating channels is one way in which the beavers modify the environment and create dynamic habitats. Channels such as these spread and diversify the flow of water and create fantastic habitat for a variety of wildlife, particularly water voles. In straightened modified rivers, water voles are severely under threat from predation from species such as the invasive, non-native American mink as they can swim up and down a straight narrow river and pick off water vole easily. In a more dynamic and varied beaver wetland, these channels create essential hiding places for water voles and make it harder for predators such as mink to get to them, greatly reducing their rate of predation. More beavers = more water voles!  

Amphibians emerging

At the start of spring, we carried out our annual frogspawn surveys and mapped where we found spawn across the site. The abundance and spread of frog spawn has been increasing year-on-year at the site, and this year we have for the first time found frog spawn in a new, entirely beaver-created pond, one that did not exist prior to the beaver's arrival and where no frogspawn had been recorded previously. The beavers seem to have slowly created and expanded the ideal habitat for frogs to breed since their arrival in 2021. The spawn is progressing nicely in the warm weather and the water is now buzzing with movement from the clumps of tiny tadpoles wiggling around. We also carried out refugia surveys (where an artificial refuge such as a corrugated tin or felt mat is placed in suitable habitat to attract reptiles), beginning in April, and during our pre-survey checks encountered a smooth newt sheltering under one of the refugia, which was great to see.

This week we are starting with something most rodents are well known for, and which are especially important for beavers - their teeth! 

Beavers have twenty teeth in total, including four large incisors at the front. A beaver’s teeth are unique in the animal kingdom due to one obvious feature – their colour. A beaver’s teeth are a rusty orange colour due to the high iron levels in the tooth's structure, giving them particularly tough enamel, making them exceptionally strong and durable. In fact, beaver teeth are made mainly of two components – iron and dentine. This structure also gives the beavers another advantage for munching on wood. The dentine is found at the back of the teeth, with the iron at the front. This dentine is softer than the iron front and therefore wears down quicker. This gives beavers' teeth their distinctive and extremely effective chisel-like sharp cutting edge.  

Having so much iron in their teeth also makes them resistant against tooth decay – which is vital to beavers given how much they use their teeth. These adaptations give beavers teeth which are unrivalled in shape and strength, just what’s needed when you're chewing on wood all day. Beavers' teeth, like other rodents, are continuously growing so they need to gnaw on wood to keep them the right length and in good condition.  

Did you know? A beaver can fell an eight-foot tree in just five minutes!