Wegmann specializes in understanding how humans have altered the form and function of landscape features. His interest in beavers actually started with studying the sediments at Yates Mill Pond<\/a>, a historic county park and the oldest intact mill pond in Wake County.<\/p>\n\n\n\n \u201cI came out to test the sediment captured above the mill pond and was really impressed by the beaver wetland complex located behind the dam. I thought \u2018this is how streams probably used to look,\u2019 and decided to use the dams as a template,\u201d he recalls.<\/p>\n\n\n\n It wasn\u2019t the beavers themselves Wegmann wanted to emulate but rather their building style. Could an artificial dam mimic the functions of a real one enough to return a stream to its historic flow and function?<\/p>\n\n\n\n Wegmann recruited Adam Lee, a geology graduate student at NC State, to help him with the research. A former Wake Tech Community College student, Lee jumped at the opportunity to investigate how landscapes respond to natural remediation treatments.<\/p>\n\n\n\n \u201cIf we can get valley bottoms back to a more historic, beaver-influenced form, we also may be able to improve the riparian environment and water quality,\u201d Lee says of their ultimate goal of influencing stream and ecosystem restoration efforts.<\/p>\n\n\n\n John Fear, deputy director of North Carolina Sea Grant<\/a>, sees potential benefits for coastal ecosystems, too. \u201cOur river systems flow from the Piedmont to the coastal region, and many of them have nutrient over-enrichment problems. This effort is an attempt to capture nutrients and sediment before they make their way downstream.\u201d<\/p>\n\n\n\n With funding from Sea Grant\u2019s minigrant program, Wegmann and Lee were ready to get building. But first, they needed to take a few lessons from the masters to perfect their technique.<\/p>\n\n\n\n Weighing in at 35 pounds and more, beavers, Castor canadensis<\/em>, are North America\u2019s largest rodent. These industrious herbivores whittle away at trees with their incredibly strong teeth, felling them to eat the leaves, twigs and inner bark and to stockpile the branches and whole trees for building dams.<\/p>\n\n\n\n Beavers construct their dams on flowing water, causing back ups and creating ponds deep enough for them to swim in. While beavers usually stay away from humans, settlers found it hard to resist their luxurious, dark chestnut-colored fur. By the 1890s, trappers had completely wiped out North Carolina\u2019s beavers.<\/p>\n\n\n\n Ironically, the demand for pelts was a driver for reintroducing beavers to North Carolina in the late 1930s, explains Jessie Birckhead, a wildlife biologist with the N.C. Wildlife Resources Commission<\/a>. \u201cThey originally released just 29 beavers from Pennsylvania into the Sandhills, with a bigger effort to spread them out across the state in the early 1950s.\u201d<\/p>\n\n\n\n Now, she adds, conflicts happen regularly as beavers continue to change how water moves across the landscape, increasingly in areas with costly infrastructure. \u201cBeavers and people probably can\u2019t coexist in every situation, but it\u2019s important to emphasize the value beavers bring to our ecosystems for society and for wildlife.<\/p>\n\n\n\n \u201cDuck hunters and bird watchers, for example, are big champions of beavers because they create tremendous waterfowl habitat.\u201d<\/p>\n\n\n\n This was true at Yates Mill Pond where people visited the beaver-controlled wetlands to view flocks of waterfowl \u2014 at least until a storm in 2014 destroyed the dams. The beavers never returned and the wetlands mostly dried out, leaving an ideal area for Wegmann and Lee to construct their own dam prototypes.<\/p>\n\n\n\n Prior to any construction, Lee measured different water-quality and landscape parameters at the Yates Mill site to establish a baseline for future analyses. He also conducted similar tests at Blackley Pond, a privately owned, beaver-controlled wetland complex in northeastern Wake County.<\/p>\n\n\n\n \u201cBlackley Pond is a great test site because the dams are so established; they are not temporary,\u201d Wegmann notes.<\/p>\n\n\n\n Some of these measurements are taken from the sky. The researchers regularly fly a briefcase-sized drone along a preset flight path to capture imagery and small changes in elevation at the test site.<\/p>\n\n\n\n Based on research done out west, Lee came up with the design for a beaver dam analog, or BDA. The BDAs use rows of untreated lumber driven into the streambed sediment and interlaced with sticks to slow the flow of water. Wanting to block the flow even more to encourage overbank flooding, they reinforced the BDAs with clay, Lee adds.<\/p>\n\n\n\n After setting up the first three BDAs along Swift Creek as it flows through Yates Mill in January, Lee brought in a few outside experts to evaluate the structures. \u201cI had another graduate student come out to look and she mentioned that the analogs weren\u2019t nearly as thick or deep as real dams,\u201d he shares.<\/p>\n\n\n\n The team continued to tweak the design by adding layers, similar to what beavers would do in the wild. In fact, after several months, a curious beaver decided to take up residence in one of the dams.<\/p>\n\n\n\n \u201cWe actually were interested in how the BDAs could jumpstart the process of bringing back beavers so it wasn\u2019t a big problem,\u201d Lee says. Beavers prefer smaller streams with lower banks, making many of the highly incised channels unsuitable.<\/p>\n\n\n\n However, just a week after moving in, the beaver was forced to move out when a large April rainstorm blew out all three BDAs. Lee used this as an opportunity to take some additional water-quality measurements and reevaluate the project scope.<\/p>\n\n\n\n After deciding to scale down the number of structures to just one, Lee completed construction of the new BDA in June. He had help from Dustin Travels, another NC State student.<\/p>\n\n\n\n Travels is just one of seven students working with Lee this summer; the others are current Wake Tech students participating in a joint internship program with NC State\u2019s Department of Marine, Earth and Atmospheric Sciences<\/a>. Funded by the National Science Foundation<\/a>, the program \u2014 known as DIG-MAPS \u2014 provides paid research experiences for Wake Tech students interested in geology.<\/p>\n\n\n\n \u201cThe program is now in its sixth year and over 60 students have participated, including those working with Karl Wegmann this summer,\u201d notes John Fountain, a researcher at NC State and DIG-MAPS project lead.<\/p>\n\n\n\n \u201cOver 90 percent of the students who have participated in the summer research opportunities have indicated they intend to major in geology. Many have transferred to NC State or other state schools.\u201d<\/p>\n\n\n\n Lee participated in the very first summer of the program as a Wake Tech student, and enjoys helping others by providing hands-on experiences. \u201cWe involve them in pilot projects so they\u2019re not just collecting samples,\u201d he explains.<\/p>\n\n\n\n \u201cIt\u2019s an opportunity to potentially participate in groundbreaking research. And the students that participate have been very successful in transferring to larger universities.\u201d<\/p>\n\n\n\n Travels is one such example, having just finished his first year at NC State. He\u2019s interested in further studying how the BDAs could trap or filter other pollutants such as hydrocarbons in urban environments.<\/p>\n\n\n\n \u201cThis research is definitely giving me a foundation to build off of and potentially to pursue a master\u2019s thesis,\u201d he says.<\/p>\n\n\n\n While they are still working on collecting data from the reconstructed BDA, Lee hopes this pilot project will lead to more demonstration projects and eventually, implementation at the watershed scale.<\/p>\n\n\n\n \u201cOur hope is to take the data we were able to collect with the minigrant funds and use it to model beaver dam potential and associated water-quality benefits for larger projects,\u201d Lee reveals.<\/p>\n\n\n\n They already are seeing local benefits in the diversity of organisms attracted to the BDAs. \u201cBeavers are a keystone species and they bring in a whole ecosystem. We\u2019re seeing more snapping turtles, water turtles and watersnakes that stop by to fish for the minnows that congregate,\u201d Travels recounts.<\/p>\n\n\n\n Lee also emphasizes the positive ecological benefits associated with beavers, adding, \u201cwe want people to recognize the inherent value in beavers controlling these wetland systems.<\/p>\n\n\n\n \u201cLetting nature repair itself may be more cost-effective.\u201d<\/p>\n\n\n\n In essence, maybe we should leave it to beaver.<\/p>\n\n\n\n The beaver, Castor canadensis<\/em>, is the largest North American rodent. Its stocky, compact body is covered with rich brown fur. It has webbed hind feet and a broad and flattened scaly tail.<\/p>\n\n\n\n The average adult weighs 35 to 40 pounds. When beavers reach 2-1\/2 years of age, they select mates for life.<\/p>\n\n\n\n There is one species of the beaver in North America. Beavers are distributed statewide in North Carolina.<\/p>\n\n\n\n \u2022<\/strong> Classification<\/strong><\/em> \u2022<\/strong> Average Size<\/strong><\/em> \u2022<\/strong> Food<\/strong><\/em> \u2022<\/strong> Breeding<\/strong><\/em> \u2022<\/strong> Young<\/strong><\/em> \u2022<\/strong> Life Expectancy<\/strong><\/em> This information is adapted from the N.C. Wildlife Resources Commission. For more on beavers, go to www.ncwildlife.org<\/a> and search for <\/em>beaver.<\/em><\/p>\n\n\n\n This article was published in the Autumn 2017<\/a> issue of <\/em>Coastwatch.<\/em><\/p>\n\n\n\nGnawing at History<\/strong><\/h2>\n\n\n\n
Back to Beaver Basics<\/strong><\/h2>\n\n\n\n
![\"Blackley](\"https:\/\/ncseagrant.ncsu.edu\/coastwatch\/wp-content\/uploads\/sites\/13\/2017\/09\/Blackley-Pond.jpg\")
Take Two<\/strong><\/h2>\n\n\n\n
![\"beaver](\"https:\/\/ncseagrant.ncsu.edu\/coastwatch\/wp-content\/uploads\/sites\/13\/2017\/09\/beaver-dam_web.jpg\")
BEAVER FACTS<\/h3>\n\n\n\n
Class: Mammalia
Order: Rodentia<\/p>\n\n\n\n
Length: 2 to 4 feet
Weight: females 30 to 70 lbs., males 30 to 80 lbs.<\/p>\n\n\n\n
Bark, twigs, leaves, pond lilies, reeds, duckweed, alfalfa and clover.<\/p>\n\n\n\n
Monogamous. Sexually mature in two to three years. Mate for life and produce a single litter each spring.<\/p>\n\n\n\n
Called kits. One litter per year, born in spring after gestation period of about four months. Typical litter contains two to six kits, eyes open at birth, weaned in six to eight weeks. Kits stay with mother the first year, remain with colony as yearlings for their second year.<\/p>\n\n\n\n
May live 20 years, but usually half that or less.<\/p>\n\n\n\n