Give A Dam

Eoin Dillon

The highs and lows of the Eurasian Beaver

With their paddle shaped tails, buck teeth and their penchant for deciduous delicacies, beavers truly are a remarkable and recognisible species. I believe it’s safe to say no other animal on the planet has such a noticeable impact on the environment they live in than the beaver (humans excluded obviously). As ecosystem engineers they can change the fundamental characteristics of the area they are living in, by raising the water level through their dams and thus creating wetlands. However few of us may be aware of the roller coaster ride their populations have faced, going from a common occurrence, to near extinction to a flagship species of successful reintroductions.

The Eurasian Beaver. Image Credit

Hundreds of years ago the Eurasian Beaver (Castor fiber) would have been a common sight throughout Eurasia. Its range stretched from Britain and Western Europe all the way to Mongolia and China. They were hunted to near extinction for their fur and castoreum and by the beginning of the 20th century it is estimated that only 1200 of these animals survived in eight scattered populations [1]. Castoreum is a yellow liquid secreted from the castor sac of the beaver. It is used to scent mark territories by the beavers by mixing it with their urine. For millennia humans have used castoreum for a range of reasons. The Romans would have woman inhale it to try and induce abortions, and would burn it in their lamps. Medieval beekeepers would use it to try and increase honey production and keep away predatory bees. And more recently it has been used in perfumes and medicines [2]. But unfortunately their soft fur, and useful secretion essentially placed a large “shoot me” sign over these rodents. Combine this with their easy to spot dams, it made beavers an easy target for hunters for a long time.

Dammed if you do. Image Credit

It would have been a great shame to lose the beavers due to our exploitation, but that was very nearly the case by the 1900s. They were extinct from almost all of their former range, and the populations that had survived lived scattered across the continent in France, Germany, Norway, Belarus and Russia. Beginning with a hunting ban in Norway in 1845, governments have been making huge strides in reintroducing and protecting the Eurasian Beaver. In recent decades this recovery in both population and range has been quite noticeable. By 1998 the global population was estimated at 430,000 [3]. By 2002 this had reached 593,000 [4] and in 2006 it was 639,000 [1]. This growth has continued and the beaver is still making considerable expansions in Western Europe and along the Danube basin. However the population across Asia still remain quite small, with around 150 beavers remaining in Mongolia, and about 700 in China.

A full formal reintroduction has yet to take place in Britain, but currently the Scottish government intends to give protection to a trial reintroduction that took place in Argyll, making it the first mammal to be reintroduced into Britain. Scottish farmers do have some very fair worries about this, as Beavers will flood the areas they build dams and potentially infringe on some of the lowland farmers fields. However I have full faith in the Scottish government that the protection and spread of the Eurasian Beaver can be done in such a way as to work for both land owners in Scotland, and these amazing creatures.


  1. (2017). Castor fiber (Eurasian Beaver). [online] Available at: [Accessed 6 Aug. 2017].
  2. Müller-Schwarze, D. . The Beaver: Its Life and Impact. p.43.
  3. Nolet, B. and Rosell, F. (1998). Comeback of the beaver Castor fiber: An overview of old and new conservation problems. Biological Conservation, 83(2), pp.165-173.
  4. Halley, D. and Rosell, F. (2002). The beaver’s reconquest of Eurasia: status, population development and management of a conservation success. Mammal Review, 32(3), pp.153-178.
  5. Cramb, A. (2017). Eurasian beavers to be given formal protection and allowed to remain in Scottish countryside. [online] The Telegraph. Available at: [Accessed 6 Aug. 2017].


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s