Benefits of Beavers
Did you know that beavers:
- are a keystone species and can change the entire ecosystem with their presence?
- are responsible for the critical cycle of the forest?
- help humans by creating fertile land for agriculture and areas for outdoor recreation?
- improve water quality and groundwater storage?
- create habitat for all types of wildlife which helps increase the amount of wildlife in certain areas?
Beavers are a Keystone Species
In architecture the keystone is a wedge-shaped piece of material at the apex of an arch that holds the rest of the arch together [1]. Without the keystone, the arch struggles to maintain its structural integrity and may fall apart completely! The keystone concept can also be applied to nature in the form of a "keystone species." A keystone species is an organism that exerts significant influence over the rest of the organisms in an ecosystem, with much more influence than its abundance would suggest [2]. The North American Beaver is considered a "keystone modifier," which is a keystone species that influences the amount, type, and activities of species due to their ability to significantly alter their environment [3].
Beavers are responsible for the centuries-long and necessary cycle found in wooded areas. When beavers build a dam in a stream or river the pond that develops back fills the area behind it creating a new aquatic habitat where animals such as small and large mammals, fish, insects, and birds may live [4]. Some of these animals may be threatened or endangered, depend on beaver ponds for habitat and survival [4,5]. This newly formed pond allows beavers to chew down trees which opens the forest canopy allowing plants and shrubs to grow in and around the pond [5]. Over time the trees closest to the pond have been felled and silt and plant debris cause the pond to become too shallow to support beaver activity [5]. The beavers soon leave the area in search of another stream to colonize and in their absence, the dam eventually breaches [5]. Following the draining of the pond, the nutrient-rich pond bed slowly becomes a meadow which supports its own variety of plants and animals [5]. Eventually, the meadow reverts back into a forest and the cycle repeats itself once new beavers find their way to the area [5].
In architecture the keystone is a wedge-shaped piece of material at the apex of an arch that holds the rest of the arch together [1]. Without the keystone, the arch struggles to maintain its structural integrity and may fall apart completely! The keystone concept can also be applied to nature in the form of a "keystone species." A keystone species is an organism that exerts significant influence over the rest of the organisms in an ecosystem, with much more influence than its abundance would suggest [2]. The North American Beaver is considered a "keystone modifier," which is a keystone species that influences the amount, type, and activities of species due to their ability to significantly alter their environment [3].
Beavers are responsible for the centuries-long and necessary cycle found in wooded areas. When beavers build a dam in a stream or river the pond that develops back fills the area behind it creating a new aquatic habitat where animals such as small and large mammals, fish, insects, and birds may live [4]. Some of these animals may be threatened or endangered, depend on beaver ponds for habitat and survival [4,5]. This newly formed pond allows beavers to chew down trees which opens the forest canopy allowing plants and shrubs to grow in and around the pond [5]. Over time the trees closest to the pond have been felled and silt and plant debris cause the pond to become too shallow to support beaver activity [5]. The beavers soon leave the area in search of another stream to colonize and in their absence, the dam eventually breaches [5]. Following the draining of the pond, the nutrient-rich pond bed slowly becomes a meadow which supports its own variety of plants and animals [5]. Eventually, the meadow reverts back into a forest and the cycle repeats itself once new beavers find their way to the area [5].
Beavers Help Humans
One of the advantages of the fertile meadows that beavers help create is agricultural use. When used correctly and responsibly a beaver pond turned meadow provides excellent pastures for livestock and crop farming [6]. Ancient humans are thought to have taken advantage of beaver meadows and areas cleared of trees for hunting and primitive agriculture [6]. Some scientists believe the rich farmlands found near Troy in New York State are thanks to centuries of beavers building so many beaver ponds that a 400 km by 400-800 m valley turned into fertile and level farmland [6]! Since beaver ponds also increase the amount of habitat for wildlife, humans have access to more natural resources where we can engage fishing, hunting, animal watching, and other recreational activities [6].
One of the advantages of the fertile meadows that beavers help create is agricultural use. When used correctly and responsibly a beaver pond turned meadow provides excellent pastures for livestock and crop farming [6]. Ancient humans are thought to have taken advantage of beaver meadows and areas cleared of trees for hunting and primitive agriculture [6]. Some scientists believe the rich farmlands found near Troy in New York State are thanks to centuries of beavers building so many beaver ponds that a 400 km by 400-800 m valley turned into fertile and level farmland [6]! Since beaver ponds also increase the amount of habitat for wildlife, humans have access to more natural resources where we can engage fishing, hunting, animal watching, and other recreational activities [6].
Beavers can Improve Water Quality and Groundwater Storage!
Imagine an animal being able to improve water quality just by being part of the environment! That animal is the North American beaver. Thanks to the beaver's ability to create dams in water ways, water is slowed on the way to wherever it ends up. This slowing of the water increases the amount of sediment that can settle along the bottom of the water body and decreases erosion which adds more sediment to the water [7]. This settling, called aggradation, improves water quality for animals (including humans) and plants.
Slower water also allows nutrients to be stored in sediment instead of continuing downstream [7,8]. While nutrients are good in low amounts, too many nutrients in our water ways is not good for the environment. Nutrient pollution occurs when runoff from lawns, gardens, pet waste, and agricultural fields enters bodies of water [9]. One of the most potent nutrients that commonly enters water is nitrogen, a common nutrient in fertilizers meant to make plants grow bigger and faster [9]. Nitrogen can cause algae blooms which grow to cover the entire surface of the water, blocking sunlight to aquatic plants and using up all the dissolved oxygen in the water once they die. Without oxygen, massive fish, invertebrate, and amphibian die-offs can occur. Luckily, when beavers are around their water-slowing dams allows nitrogen to settle in the substrate and be stored away for the future [7,10].
Imagine an animal being able to improve water quality just by being part of the environment! That animal is the North American beaver. Thanks to the beaver's ability to create dams in water ways, water is slowed on the way to wherever it ends up. This slowing of the water increases the amount of sediment that can settle along the bottom of the water body and decreases erosion which adds more sediment to the water [7]. This settling, called aggradation, improves water quality for animals (including humans) and plants.
Slower water also allows nutrients to be stored in sediment instead of continuing downstream [7,8]. While nutrients are good in low amounts, too many nutrients in our water ways is not good for the environment. Nutrient pollution occurs when runoff from lawns, gardens, pet waste, and agricultural fields enters bodies of water [9]. One of the most potent nutrients that commonly enters water is nitrogen, a common nutrient in fertilizers meant to make plants grow bigger and faster [9]. Nitrogen can cause algae blooms which grow to cover the entire surface of the water, blocking sunlight to aquatic plants and using up all the dissolved oxygen in the water once they die. Without oxygen, massive fish, invertebrate, and amphibian die-offs can occur. Luckily, when beavers are around their water-slowing dams allows nitrogen to settle in the substrate and be stored away for the future [7,10].
An important result of the formation of ponds or lakes is the influence these water bodies have on groundwater. In areas surrounding beaver dams, groundwater monitoring shows higher water table elevations, greater storage potential for groundwater, and greater aquifer recharge [11]. Since groundwater is one of the best and largest sources of freshwater in the world it is very important to keep groundwater aquifers full and replenished [12]. Unfortunately, in many parts of the United States excessive pumping of groundwater can cause wells to stop working, land collapse, and saltwater intrusion in coastal areas [12]. As the human population expands, more and more water is being pulled out of the ground faster than it can be replaced. Since beaver ponds and lakes are so heavy, the water is forced underground which replenishes the groundwater extracted by human [12]. Beaver ponds have also been tied to more stable water flow during dry and wet periods alike, as the stored groundwater allows consistent stream flow during dry spells and the beaver dam slows the velocity of water during periods of heavy rainfall [11]. This helps prevent flooding which prevents erosion of our waterways and can help prevent damage to nearby homes that would otherwise be flooded.
Beavers Help Wildlife!
One of the most obvious type of animals that would benefit from beavers are fish! Beaver dams create new homes for many different fish species to live by changing a shallow stream into a deep body of water with many different habitats [6]. These new habitats provide fish with new spaces to breed, hide from predators, find food, and overwinter [6,13]. Fish like salmon, trout, pike, and many more are then able to occupy areas that would otherwise be inhospitable to them [6,13]. At times, beaver dams can block fish migration, but migrating fish are usually able to jump over the dams, swim up the dam discharge, or swim around the dams [6]. Migrating fish generally only face trouble in years with lower than average rainfall [13].
One of the most obvious type of animals that would benefit from beavers are fish! Beaver dams create new homes for many different fish species to live by changing a shallow stream into a deep body of water with many different habitats [6]. These new habitats provide fish with new spaces to breed, hide from predators, find food, and overwinter [6,13]. Fish like salmon, trout, pike, and many more are then able to occupy areas that would otherwise be inhospitable to them [6,13]. At times, beaver dams can block fish migration, but migrating fish are usually able to jump over the dams, swim up the dam discharge, or swim around the dams [6]. Migrating fish generally only face trouble in years with lower than average rainfall [13].
Along with the creation of pond and lakes beaver dams also create more wetland habitat that amphibians and reptiles live in. Compared to areas without beaver ponds, areas with beaver ponds have much higher amounts of amphibians and reptiles, especially when beaver ponds have been present for a long time [6,8,14,15]. Turtles and lizards are especially at home in areas in and around beaver ponds, but frogs and salamanders make the most use out of these ponds [14,15]. Newts, like the red-spotted newt may depend on beaver ponds to survive as a species [6]. Frog species like the wood frog, chorus frog, and western toad also may depend on beaver ponds for breeding, mating, and living and can be found in much higher numbers in the areas around beaver ponds than in unimpeded streams [6,14].
Birds are another type of animal that benefits greatly from the presence of beavers. Beavers create new areas of habitat for waterfowl who have been found to prefer breeding, mating, feeding, and living in beaver ponds more than in other areas [6,8]. Waterfowl such as ducks, grebes, geese, and swans are attracted to beaver ponds due to their higher levels of food and shelter compared to areas without beavers [6,8]. Some species like trumpeter swans may even depend on beavers to keep their populations high! Trumpeter swans often choose to lay their eggs and raise their young on small islands such as beaver lodges [16]. As beavers were over hunted, trumpeter swans no longer had access to beaver lodges place to build their nests and their populations began to fall due to predators eating their young from nests they were forced to build on shore [17]. Once beaver populations began to rise, trumpeter swan populations did too! Other kinds of birds like woodpeckers, wader birds, flycatchers, and song birds also love beaver ponds [6]. The abundance of food and dead trees for nesting found in beaver areas seems to be very appealing for all types of birds [6]. The unique skills of beavers can allow them to turn once desolate areas into wetlands and ponds that all types of birds love to call home.
Mammals are also incredibly influenced by the presence of beavers. Besides from providing mammals an ample supply of water, beaver ponds also provide lots of insects and terrestrial and aquatic plants that mammals can feed on [6,8]. Animals like deer, bear, and raccoons spend lots of time feeding on the variety of food that is available in and around beaver ponds [6,8]. Moose are especially dependent on beaver ponds for food and they will spend a substantial amount of time feeding on the vegetation in and around beaver ponds that make up a large amount of their diet [6,8]. Beaver ponds are so important to moose populations that New York State studies the number of beaver ponds available in order to calculate the carrying capacity of moose every year [6,8]!
References
1. Keystone. (n.d.). Retrieved from https://www.merriam-webster.com/dictionary/keystone
2. Paine, R. (1995). A Conversation on Refining the Concept of Keystone Species. Conservation Biology, 9(4), 962–964. doi: 10.1046/j.1523-1739.1995.09040962.x
3. Wagner, S. C. (2010) Keystone Species. Nature Eduation Knowledge 3(10):51
4. North American Beaver, North American Beaver (2016)
5. Beaver Natural History Narrative. (2015, February 24). Retrieved from https://www.nps.gov/glac/learn/education/beaver-natural-history-narrative.htm
6. Muller-Schwarze, D. (2011). The Beaver : Natural History of a Wetlands Engineer: Vol. 2. ed. Comstock Publishing Associates.
7. Bason, C. W., Kroes, D. E., & Brinson, M. M. (2017). The Effect of Beaver Ponds on Water Quality in Rural Coastal Plain Streams. Southeastern Naturalist, 16(4),
584–602. doi: 10.1656/058.016.0408
8. Baker, B. W., and E. P. Hill. (2003). Beaver (Castor canadensis). Pages 288-310 in G. A. Feldhamer, B. C. Thompson, and J. A. Chapman, editors. Wild Mammals of
North America: Biology, Management, and Conservation. Second Edition. The Johns Hopkins University Press, Baltimore, Maryland, USA
9. US Department of Commerce, & National Oceanic and Atmospheric Administration. (2009, September 1). What is nutrient pollution? Retrieved from
https://oceanservice.noaa.gov/facts/nutpollution.html
10. Lazar, J. G., Addy, K., Gold, A. J., Groffman, P. M., Mckinney, R. A., & Kellogg, D. Q. (2015). Beaver Ponds: Resurgent Nitrogen Sinks for Rural Watersheds in the
Northeastern United States. Journal of Environmental Quality, 44(5), 1684–1693. doi: 10.2134/jeq2014.12.0540
11. Gibson, P. P., & Olden, J. D. (2014). Ecology, management, and conservation implications of North American beaver(Castor canadensis)in dryland streams. Aquatic
Conservation: Marine and Freshwater Ecosystems, 24(3), 391–409. doi: 10.1002/aqc.2432
12. Groundwater overuse. (n.d.). Retrieved from https://www.groundwater.org/get informed/groundwater/overuse.html
13. Kemp, P. S., Worthington, T. A., Langford, T. E. L., Tree, A. R. J., & Gaywood, M. J. (2011). Qualitative and quantitative effects of reintroduced beavers on stream
fish. Fish and Fisheries, 13(2), 158–181. doi: 10.1111/j.1467-2979.2011.00421.x
14. Stevens, C. E., Paszkowski, C. A., & Foote, A. L. (2007). Beaver (Castor canadensis) as a surrogate species for conserving anuran amphibians on boreal streams in
Alberta, Canada. Biological Conservation, 134(1), 1–13. doi: 10.1016/j.biocon.2006.07.017
15. Russell, K. R., Moorman, C. E., Edwards, J. K., Metts, B. S., & Guynn, D. C. (1999). Amphibian and Reptile Communities Associated with Beaver (Castor
canadensis) Ponds and Unimpounded Streams in the Piedmont of South Carolina. Journal of Freshwater Ecology, 14(2), 149–158. doi:
10.1080/02705060.1999.9663666
16. Trumpeter Swan. (2020, February 4). Retrieved from https://www.audubon.org/field-guide/bird/trumpeter-swan
17. Trumpeter Swan Overview, All About Birds, Cornell Lab of Ornithology. (n.d.). Retrieved from https://www.allaboutbirds.org/guide/Trumpeter_Swan/overview
Picture References in Order of Use
Greer, Solomon. [nd.]. Lesson on Ecosystem Change due to Biotic and Abiotic factors. [SlidePlayer Slide]. Retrieved from https://tinyurl.com/y9lqzz4w
Jim O'Neal Fly Fishing. [2017]. Beaver Pond Fly Fishing Approach Strategy Utah. [Still from YouTube Video]. Retrieved from https://tinyurl.com/y7ot8tt2
Eutrophication&hypoxia. [2007]. Algae and Dead Fish in Dianchi Lake, China. [Photograph]. Retrieved from https://tinyurl.com/ydfhrdte
The Groundwater Foundation. [2020]. What is Groundwater? [Diagram]. Retrieved from https://tinyurl.com/y7lzj9vo
Licis, Karl. [2016]. Colorful Brook Trout... [Photograph]. Retrieved from https://tinyurl.com/y7rendtf
Kersting, Steven. [2016]. Easter Red Spotted Newt Eft. [Photograph]. Retrieved from https://tinyurl.com/yaxqxg39
Benson, Tom. [2016]. Western Toad. [Photograph]. Retrieved from https://tinyurl.com/y8zk84cq
Christainsen, Julie. [2013]. Trumpeter Swan on Beaver Lodge. [Photograph]. Retrieved from https://tinyurl.com/y943ghuh
Amy the Nurse. [2011]. Moose @ Beaver Ponds. [Photograph]. Retrieved from https://tinyurl.com/ycctjawe
1. Keystone. (n.d.). Retrieved from https://www.merriam-webster.com/dictionary/keystone
2. Paine, R. (1995). A Conversation on Refining the Concept of Keystone Species. Conservation Biology, 9(4), 962–964. doi: 10.1046/j.1523-1739.1995.09040962.x
3. Wagner, S. C. (2010) Keystone Species. Nature Eduation Knowledge 3(10):51
4. North American Beaver, North American Beaver (2016)
5. Beaver Natural History Narrative. (2015, February 24). Retrieved from https://www.nps.gov/glac/learn/education/beaver-natural-history-narrative.htm
6. Muller-Schwarze, D. (2011). The Beaver : Natural History of a Wetlands Engineer: Vol. 2. ed. Comstock Publishing Associates.
7. Bason, C. W., Kroes, D. E., & Brinson, M. M. (2017). The Effect of Beaver Ponds on Water Quality in Rural Coastal Plain Streams. Southeastern Naturalist, 16(4),
584–602. doi: 10.1656/058.016.0408
8. Baker, B. W., and E. P. Hill. (2003). Beaver (Castor canadensis). Pages 288-310 in G. A. Feldhamer, B. C. Thompson, and J. A. Chapman, editors. Wild Mammals of
North America: Biology, Management, and Conservation. Second Edition. The Johns Hopkins University Press, Baltimore, Maryland, USA
9. US Department of Commerce, & National Oceanic and Atmospheric Administration. (2009, September 1). What is nutrient pollution? Retrieved from
https://oceanservice.noaa.gov/facts/nutpollution.html
10. Lazar, J. G., Addy, K., Gold, A. J., Groffman, P. M., Mckinney, R. A., & Kellogg, D. Q. (2015). Beaver Ponds: Resurgent Nitrogen Sinks for Rural Watersheds in the
Northeastern United States. Journal of Environmental Quality, 44(5), 1684–1693. doi: 10.2134/jeq2014.12.0540
11. Gibson, P. P., & Olden, J. D. (2014). Ecology, management, and conservation implications of North American beaver(Castor canadensis)in dryland streams. Aquatic
Conservation: Marine and Freshwater Ecosystems, 24(3), 391–409. doi: 10.1002/aqc.2432
12. Groundwater overuse. (n.d.). Retrieved from https://www.groundwater.org/get informed/groundwater/overuse.html
13. Kemp, P. S., Worthington, T. A., Langford, T. E. L., Tree, A. R. J., & Gaywood, M. J. (2011). Qualitative and quantitative effects of reintroduced beavers on stream
fish. Fish and Fisheries, 13(2), 158–181. doi: 10.1111/j.1467-2979.2011.00421.x
14. Stevens, C. E., Paszkowski, C. A., & Foote, A. L. (2007). Beaver (Castor canadensis) as a surrogate species for conserving anuran amphibians on boreal streams in
Alberta, Canada. Biological Conservation, 134(1), 1–13. doi: 10.1016/j.biocon.2006.07.017
15. Russell, K. R., Moorman, C. E., Edwards, J. K., Metts, B. S., & Guynn, D. C. (1999). Amphibian and Reptile Communities Associated with Beaver (Castor
canadensis) Ponds and Unimpounded Streams in the Piedmont of South Carolina. Journal of Freshwater Ecology, 14(2), 149–158. doi:
10.1080/02705060.1999.9663666
16. Trumpeter Swan. (2020, February 4). Retrieved from https://www.audubon.org/field-guide/bird/trumpeter-swan
17. Trumpeter Swan Overview, All About Birds, Cornell Lab of Ornithology. (n.d.). Retrieved from https://www.allaboutbirds.org/guide/Trumpeter_Swan/overview
Picture References in Order of Use
Greer, Solomon. [nd.]. Lesson on Ecosystem Change due to Biotic and Abiotic factors. [SlidePlayer Slide]. Retrieved from https://tinyurl.com/y9lqzz4w
Jim O'Neal Fly Fishing. [2017]. Beaver Pond Fly Fishing Approach Strategy Utah. [Still from YouTube Video]. Retrieved from https://tinyurl.com/y7ot8tt2
Eutrophication&hypoxia. [2007]. Algae and Dead Fish in Dianchi Lake, China. [Photograph]. Retrieved from https://tinyurl.com/ydfhrdte
The Groundwater Foundation. [2020]. What is Groundwater? [Diagram]. Retrieved from https://tinyurl.com/y7lzj9vo
Licis, Karl. [2016]. Colorful Brook Trout... [Photograph]. Retrieved from https://tinyurl.com/y7rendtf
Kersting, Steven. [2016]. Easter Red Spotted Newt Eft. [Photograph]. Retrieved from https://tinyurl.com/yaxqxg39
Benson, Tom. [2016]. Western Toad. [Photograph]. Retrieved from https://tinyurl.com/y8zk84cq
Christainsen, Julie. [2013]. Trumpeter Swan on Beaver Lodge. [Photograph]. Retrieved from https://tinyurl.com/y943ghuh
Amy the Nurse. [2011]. Moose @ Beaver Ponds. [Photograph]. Retrieved from https://tinyurl.com/ycctjawe