Humans are not the only species on Earth that use technology to manipulate their surroundings and construct impressive structures. The beaver, the second largest rodent on our planet, has abilities similar to humans, in certain respects. They have the ability to build dams that can last for decades or even more. Plus, unlike most man-made structures, which often cause deforestation and lead to biodiversity loss, the construction of beaver dams goes in the exact opposite direction. in return – increase species richness, reduce soil erosion, prevent flooding, improve water quality and, of course, provide fur beavers with a cozy home.
The most important advantage of beaver dams is that they promote the development of natural wetlands where, according to a report from the United Nations, almost 40% of all species (including many endangered species) species) on Earth depend on wetlands for survival. So beavers play an important role in improving and maintaining the health of many ecosystems.
Because they can bring changes to the natural landscape with their construction skills, beavers are also known as ecosystem engineers. Beaver dams can even help filter out pollution, and certainly the beaver’s impact on the environment is significant – and often positive.
Why do beavers build dams?
Beavers as prey are usually coyotes, bears, lynxes, foxes, wolves, and humans can easily catch beavers on land – but underwater, beavers can quickly flee and escape death with webbed toes, better suited for swimming than walking.
This is also why to stay out of reach of predators, beavers need to build dams on the water. These dams divide the waters and lead to the formation of deep pools and ponds where beavers nest.
Fast currents can damage nests and make them wet, but beaver dams help keep their nests dry, warm and protected at all times by acting as a barrier. Dams restrict the flow of water and cause water levels to rise behind them, promoting an environment suitable for beavers.
Beaver nests are always built on deep lakes, ponds and streams so that when the water begins to freeze during winter, their underwater entrance will not be blocked.
Furthermore, the nest with an underwater entrance cannot be easily penetrated by terrestrial predators, and in an emergency, it can also be used as a tunnel for quick escape. Thus, dams of this species not only improve nest comfort but also ensure their safety.
However, beavers do not always build dams for nesting, if water cannot be found suitable for dam construction, they can still nest through burrowing deep inside. underground.
How was the beaver dam built?
One thing is for sure, beavers cannot access or use the advanced tools and machines we use, but they have strong jaws and well-developed incisors. In addition, beavers also have good health, they can carry and drag objects of equal weight to them. These impressive physical features allow this species to build dams and nests that can last for years. For example, the largest beaver dam ever discovered in Wood Buffalo National Park, Alberta, Canada is believed to have been built in the 1970s. The beaver dam is about 850 meters long and researchers say it has been used and maintained by many generations of beavers.
However, not all beaver dams are so large; in fact, they are usually 1 to 2 meters tall and nearly 100 meters long. Construction of a beaver dam begins with beavers gnawing on dense tree trunks and branches located near the banks of a river or lake. Trees and branches will then fall into the water and block the flow of water, many logs and branches are stacked together to form a solid base of the dam.
Then the beavers began to pile mud, rocks, grass, twigs, leaves and small trees around the base of the dam to further expand the structure and make it stronger. When the water level on one side of the dam is deep enough to form an entrance to a winter-resistant nest, the beavers begin to build nests with chambers to rest and feed within the dam structure. Beavers rest, store food, mate and raise their young in their nests, typically a beaver family (with 5 to 10 members) will own a dam or nest. particular, and if some other beaver family tries to infiltrate, they will not hesitate to fight to the end to protect their nest.
The importance of the beaver dam for our ecosystem
Unfortunately, our planet lost 35% of its wetlands in 2015, and as the remaining wetlands are rapidly disappearing, 25% of the species that exist in wetlands now exist. are facing the danger of extinction. However, the beaver makes a significant contribution to the conservation of these remaining lands.
The deep ponds resulting from the construction of beaver dams not only provide beavers with a haven against predators, but also promote the development of wetlands, rich ecosystems The water is especially favorable for the growth of fish, birds, toads, otters and many other endangered plant and animal species. Wetlands are carbon-dense ecosystems that also play an important role in regulating climate around the world.
Recent research has consistently shown that beavers can play a role in conserving ecosystems, and the positive effects of their dams far outweigh any human actions. .
By restricting the flow of water to create a reservoir, beaver dams prevent soil erosion and flooding, while increasing the water content of the soil, this increased water content leads to the formation of new wetlands.
In addition, the beaver dam prevents harmful chemicals from running deep into the earth and oceans, it acts as a water filter and traps deposits. By creating these dams, beavers play a very important role in the management of our ecosystem and this is why they are considered as key species in the natural ecosystem.
An experiment conducted in 2016 demonstrated that the construction of beaver dams in habitats increased natural complexity and protected populations of the endangered fish – Oncorhynchus mykiss (also known as Oncorhynchus mykiss). rainbow trout or steelhead).
A 2018 case study highlights that beaver habitat changes affect benthic composition in rivers and lead to the development of invertebrates. Interestingly, even after the beaver left the altered habitat, the pond formed by the beaver dam continued to support biodiversity in the area.
Another study published in November 2020 found that beaver dams improve groundwater levels, support microbial respiration, and promote the growth of licorice and lentil species. Positively affects biochemical cycles occurring in nature, providing resistance to drought and increasing food production. A recent study from the National Resource Research Institute (NRRI) also shows that beaver dams can improve freshwater availability and contribute significantly to the conservation of wetland ecosystems.