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Brdy beaver dam -

In January 2025, a group of eight beavers built a dam in the Brdy region of the Czech Republic, saving the government a whopping US$1.2 million.

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Government plans -

The government had plans to build the dam itself, but the project had stalled after seven years of planning due to problems acquiring the necessary permits.

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Taking things into their own hands -

Living up to their reputation for being eager, the group of beavers used their exceptional skills as "ecosystem engineers" to complete the project themselves.

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Media coverage -

Reporting on Radio Prague International the morning after the rodents’ work was discovered, Jaroslav Obermajer, head of the Central Bohemian office of the Czech Nature and Landscape Protection Agency, said "Beavers always know best."

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The reason for the project -

The aim of the human dam project was to restore the area to its natural state after it was damaged by soldiers at a nearby military base.

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Bypass gully -

Decades ago, the soldiers built a bypass gully that drained the area. Previously, it had been a wetland home to various thriving species.

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Permit problems -

Although the government had secured funding for the project, it was being blocked due to issues related to building permits.

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Mid-negotiations -

According to Yahoo!, the stakeholders were negotiating with each other to settle issues of land ownership when the beavers decided to intervene.

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Overnight activity -

According to various sources, the beavers got the dam up so quickly that it appeared they completed their work overnight.

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Ecologists' verdict -

The ecologists asked to inspect the beavers’ dam determined that it will last a long time and will create good conditions for species, such as the rare stone crayfish, that thrive on wetlands.

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Ecosystem engineers -

The beavers’ effort in getting this project over the finish line is an example of their work as ecosystem engineers.

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Definition -

Ecosystem engineers are best described as animals that modify their environment and make resources available that wouldn’t be available otherwise.

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Original example -

Although beavers are the original ecosystem engineers, there are also various other species that meet the definition.

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Other ecosystem engineers -

Caterpillars, for example, are ecosystem engineers, because they use leaves to build shelters that other species can also use.

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Chewing on trees -

In the case of beavers, they use their powerful incisors to gnaw on trees and other vegetation. This is useful in the first instance because it helps to clear woodlands.

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Building dams -

However, this activity also serves a second purpose: the beavers can use some of the trees they knock down to help build dams.

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Largest beaver dam in the world -

Despite their small size, beavers can build absolutely huge dams. The largest beaver dam on record is currently located in Wood Buffalo National Park in Canada.

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Size -

This record-breaking dam, which was discovered in 2009, stretches the length of seven football fields. In fact, it is so big that it can be seen from space.

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Stormwater facility, Oregon -

Another interesting example of a beaver dam was found on the property of a large, multimillion-dollar stormwater treatment facility in Oregon.

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Filtering ability - After this dam was discovered, and scientists looked at it more closely, they realized that it was able to filter out heavy metals and other pollutants.

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Direct comparison -

In fact, in terms of its filtering abilities, the beaver-built dam was around two times more effective than the human-built structure.

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Meanwhile, in California -

Beaver dams are so effective that certain groups, such as the Yurok Tribe in California, have even started introducing beaver-dam-analogs in areas where it is illegal to introduce beavers.

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Beaver-dam-analogs -

These artificial structures, which are designed to mimic the features of natural-built beaver dams, have two main benefits.

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Beaver-like services -

On the one hand, they help to provide beaver-like ecosystem services, such as providing habitats for fish and other aquatic species.

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Fostering beaver populations -

On the other hand, they also have the potential to lure beavers towards such areas naturally, allowing beaver populations to develop in places where humans are not allowed to introduce them.

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Speculation -

In the case of the beaver dam built in the Czech Republic, there has been some speculation as to whether the team of rodents actually built the thing overnight.

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Likely course of events - Indeed, it does seem more likely that the project was ongoing for some time and humans only noticed once it was finished.

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Credit to the authorities -

It also seems appropriate to credit the Czech authorities for overseeing the reintroduction of beaver populations to the country’s ecosystem.

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Reintroduction of Eurasian beavers -

Eurasian beavers were once hunted to near extinction, but there has been a resurgence in recent years, largely thanks to reintroductions in various countries, including the Czech Republic.

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In the UK -

In the UK, too, beavers have successfully been reintroduced. In one trial between 2015 and 2020, researchers observed the first wild breeding of beavers in 400 years.

Sources: (National Geographic) (Yahoo!)

See also: How animals contribute to the Earth's ecosystems

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