International Beaver Day is a day to spotlight beavers as the amazing, transformative keystone species they are.
Beavers are the second largest rodent in the world, second only to capybara. They are inquisitive, playful and affectionate, yet can defend themselves if they feel threatened. They are social and peaceful animals with a strong family structure, but can be territorial where beavers outside of their family structure are concerned. Beavers are monogamous and usually mate for life. They typically birth between one to eight kits between May and June – the amount being dependent on the scarcity of food and the mother’s age.
Beavers weigh up to 30kg – roughly the weight of a Labrador – and have a lung capacity roughly three times that of humans, which means they can hold their breath underwater for up to 15 minutes at a time! They have a large, flat, scaly tail mainly used as a rudder when swimming. They also use this tail to slap the surface of the water, deterring predators and warning other beavers there may be danger. Their large, distinctive orange front teeth are reinforced with iron, allowing them to gnaw through wood. They are entirely herbivorous, eating a mixture of shoots, leaves, bark and aquatic plants. Their favourite tree species are aspen and willow.
When we think of beavers, most of us picture the Rocky Mountains of North America, yet beavers are actually native to the UK, hunted to extinction in the 17th Century for both their pelts and castoreum. Castoreum is a yellow, oily substance created in the scent glands of beavers, which has been used for thousands of years in perfume, food and medicine.
Beavers are often referred to as “ecosystem engineers” as their tree coppicing, dam creation and channel digging creates wetland landscapes that are dynamic and bring huge benefits to other mammals, as well as being amazing at sequestering carbon, which is more important than ever given high atmospheric CO2 levels and the very real concern of climate change. Their tree coppicing results in the formation of new stem and root systems, which can extend the life of some species, and result in the strengthening of riverbanks. Their selective felling opens up the woodland canopy, allowing light to reach both the ground – enabling the regeneration of understorey vegetation and increasing feeding opportunities for birds and bats – and water bodies – raising water temperature and potentially creating different habitats. Felled deadwood also provides both habitat and shelter for a variety of different flora and also results in more dynamic watercourses.