Reintroduction of beavers to Europe

The Eurasian beaver was hunted and trapped to the point of near extinction. Fossil evidence shows that the Eurasian beaver lived from Western Europe to the Chinese-Mongolian border. By the 12th century, only about 1,200 Eurasian beavers were left in this area, and they were extirpated from seven European countries.[1] By the 20th century, there were eight relic populations in Europe and Asia.[2]

By 2003, due to reintroduction and protection programs, there were about 639,000 beavers.[3] Successful Eurasian beaver introductions throughout Europe, including England, Scotland, Bavaria, Austria, Netherlands, Serbia, Denmark, and Bulgaria.[4] These successes resulted in Eurasian beavers listed as being of least concern on the [5] (IUCN) red list due to its fast recovery in Europe.[4] Initial reintroduction populations show a time lag between the rate of population growth and the resource growth rates. This is seen in an initial population growth followed by decrease in populations to settle into the amount of resources available to the beaver populations.[6]

1922-1939 - Sweden: About 80 beavers were reintroduced to 19 different sites over a 20-year span with an estimated 130,000 individuals present in 2014 [7][8]

1966-1982 - Bavaria: From extinction, reintroduction has increased to pupation to an estimated 6,000 individuals. As one of the oldest reintroduction sites, it is often visited and studied for the management practices.[9][10][11]

1976-1982 - Austria: Around 40 individuals were introduced in the Danube-Auen National Park downstream of Vienna. They have since then spread to the waters around the Danube inside the city as well. Today (2020), an estimated 230 beavers live in the Vienna region outside the national park proper.[12]

1988 - Romania: 21 beavers were successfully reintroduced in 1998 along the Olt River, spreading to other rivers in Covasna county [13][14]

1999 - Denmark and Northern Zealand: 18 beavers were released at Klosterheden in West Jutland. Since then, other beavers have been released at Arresø in North Zealand.[15][16]

2003 - Spain: 2003, beavers were reintroduced to the Ebro in Spain, with plans for further reintroductions to The Guadalquivir, Guadiana, and Tajo (Tagus) river systems [17]

2009-2014 - Scotland: 11 beavers were released in 2009 and four beavers were released in 2014 in the Knapdale forest [18] and 56 beavers were found at the River Tay, becoming its own study [19][20]

2019 - East Anglia: A pair of beavers was reintroduced to North Essex as part of a pioneering natural flood management scheme for East Anglia [21][22]

When first consideration reintroducing beavers into certain ecosystems, successful trials have started by raising community awareness and support. Some ways that support and awareness was created was through different community outreach and educational resources. It is reported that those that did not have community support, did not have successful beaver reintroduction.[29] As a flagship species, beavers raise awareness and resources for wide-scale riparian and woodland restoration programs by stimulating conservation awareness. Holding public forums and community events to show the community how beavers will help with their environment is important and can educate people about other environmental concerns, such as decreased Aspen forests or other riparian forest issues.[29] Furthermore, they increase ecotourism. Many areas around Europe that have reintroduced beavers have reported increased tourism, whether it is tours specific to seeing beavers, or the animals that the beavers have attracted such as birds or bats.

Some worries that people have about the reintroduction of beavers is their impact on agricultural areas, in which it was reported that some beaver dams did affect flooding of farm lands, decreasing crop yields. In order to fix this, beaver experts suggest relocating beaver dams, using water sounds to trick beavers into building the dam at different places, or using pipes in dams to help control water levels.[23] These finding were also suggested for instances when beavers created dams blocking man-made structures such as culverts. In one instance, poles were placed 10 feet in front of a culvert, changing the place of the water flow sound, in which the beavers build the dam at the poles, allowing for runoff to go through the culvert.[23] Furthermore, some farmers have reported beavers burrowing in their fields, leading to damage to machinery such as tractor and damage to crops.[30] Governments have addressed this issue by voluntarily compensating the farmers for these damages. Additionally, if the beavers are proving to be pests, there are management practices in place to relocate the beaver population to areas where they would be less disruptive. There are poorly founded concerns by some anglers, particularly in the United Kingdom, that beavers will compete with them for fish, as author C.S. Lewis depicted within The Lion, the Witch, and the Wardrobe.[31] These concerns have no standing as beaver eat vegetation and wood, and do not consume fish.