Anatomy of an urban beaver pond

Anatomy of an urban beaver pond

*** This will be the first in a series of three or four postings on the beavers that are inhabitant the detention pond under the powerlines in Centennial Woods. I've got some videos from a game cam as well as other information on how they prepare for and deal with the transition into winter. Subscribe with link to the right to keep up to date on Wild Burlington happenings!

What: The above photo I took on November 28. The pond started to freeze over on the 23rd with a thin sheet. Over the first few days the beavers were actively maintaining openwater. They've since stuck to maintain some exists along the edge of the water as well as a few openings in the middle of the water. The darker "C" shape in the middle is where the water is deeper and therefore warmer. The little snow fall we've gotten has melted into the ice. There's more snow on the right side of the pond (it's the south side and is shaded by a thick wall of white pines). The lodge is constructed on the bank. It's unclear if they've also dug into the bank while constructing it.

Walking the perimeter, they've done substantial work since they moved in about a month and a half ago. Looking at the northern border of the detention pond, there's no doubt that beavers are skilled at what they do. Each of the few dozen trees they've felled are all in perfect alignment. The one thing they didn't account for was the chainlink fence. Hopefully when the big red maple still standing in the background comes down it will crush the fence and make some of those trees a bit more accessible for the beavers.

The "dam" is really just an outlet flow structure for the detention pond. You can see the open water channel running on the upper left corner where the beavers move back and forth from their lodge to the dam to do maintenance work. They maintain holes throughout the winter, or at least try to. I'm not sure the exact reason, but I would assume it has something to do with keeping an escape route in a dire emergence and also having access to land if their food cache runs low mid-winter. It might also allow them to access early spring vegetation even if their pond hasn't frozen over.

The beavers have a number of runs that extend from the pond up to the surrounding woods. They've harvested mostly staghorn sumac, and actually have climbed a rather steep slope maybe 60' or so from the water to drag them back down. They did quite a bit of work flattening out a good deal of the phragmites, making channels to bring back the haul back to their larder.

And our beavers appear to have a flair for the artistic. I've been continually impressed at their ability to chew plants that are three plus feet off the ground. This one stood about 2.5 feet at the top.

Red Spotted Newt

Posted by Sophie Case. Sophie is a senior Environmental Studies student at the University of Vermont. She loves speaking Spanish, cooking fresh and delicious foods, and playing music. 

While hiking in the woods one dreary fall afternoon, something flashy and bright red caught my eye. It was scurrying across the ground quickly, and stopped for a quick break on top of a branch. I took a closer look, and realized that I had never seen this creature before. It looked like some sort of salamander, but I wasn?t near any running water. I quickly snapped a picture, and decided to investigate further once I got home.

As it turns out, the creature I saw was a red eft (Notophtalmus viridescens), which is the the juvenile stage of a red spotted newt, also known as the eastern newt. I found that the red spotted newt is actually quite common in North America, and tends to live in small lakes, ponds, streams, or wet forests. The range for these newts extends from South Ontario to Nova Scotia and as far south as eastern Texas and Florida. The adult stage of the red spotted newt lives mostly in aquatic environments, while the juvenile stage is a terrestrial creature. Adults range in color from from olive to brownish green, have red spots on their back, and yellow bellies. Red Efts have a completely bright orange or red body.

Red spotted newts breed in April and May. Breeding is instigated by the male who attracts the female newt to him with his bright red spots. He then releases and odor while wiggling, which further attracts the female. The two mate and lay eggs that hatch in three to four weeks. Thus begins the three stage life cycle of this amphibian. The first stage is aquatic larvae (the eggs), the second stage is terrestrial efts (the red eft), and the third and final stage is the aquatic adult. Female red spotted newts lay between 200 and 400 eggs. Once the eggs hatch, the efts spend most of their time hunting.

Their diet consists mainly of caterpillars, invertebrates, spiders, and flies. Red Spotted Newts are one of the easiest newts to keep as a pet, as far as maintenance goes, but one has to be aware that they can live up to 20 years, so it may be more of a long term investment than most pet owners are ready for. Although the ref eft isn't too uncommon to see around the woods, I was excited to see a bit of wildlife on a rainy autumn day!

Free Masons

Posted by Hannah Brill. Hannah is a Sophomore at UVM in the Environmental Program. While walking through the Green Mount Cemetery in Centennial Woods, a symbols engraved on one of the gravestones caught her eye. She decided to dig a little deeper and found something much more interesting then expected.

As I walked through Green Mount Cemetery here in Burlington I noticed a peculiar symbol embossed on one of the fancier gravestones, which belonged to the Spafford family.  The symbol is simple: a “G” engraved inside a compass and ruler (see image below). This natural history mystery led me to do a little research behind the peculiar symbol.

Once I began researching more about this mysterious symbol I opened a door into a much more peculiar world then I had expected. The engraved symbol belongs to the Freemasons. Freemasons are an international “secret” fraternity. It’s not very secret because so many people know about it. Five million of them walk among us, globally. They have lavish temples, ancient legends, and roots in the medieval crusades. The creation or beginning of the Freemasons is uncertain but some spectators say they can be traced back to the late 16th early 17th century during the stonemason guild of England, Scotland, and France.

The members of this society are powerful, among the elite include George Washington, Franklin Roosevelt, Harry Truman, Hennery Ford, Mozart, Napoleon Bonaparte, Metro-Goldwyn-Mayer MGM studios, Warner brothers, Fox, the man who created the UN and the CIA and many more. The Freemason society may not be that hush-hush but they do have many secrets that have created a lot of buzz and conspiracy’s surrounding this enigmatic club.

This organization has caused a lot of commotion over the years. Their secret rituals, handshakes, meetings, and lavish temples (their clubhouse) have made others uncomfortable. Because of the powerful elite nature of the members and the secrets they have kept for centuries has created many conspiracy theories against the freemasons. One in particular that really caught my eye was the idea that this group is actually a secret government within our government.

Some suggest that Freemasons established America to be a country of their own that they have secretly controlled since the American Revolution. There many “coincidental” occurrences that have had people wondering how true this may be. George Washington, our first president, was an avid Freemason. Above is a picture of George Washington at the laying of the cornerstone. He is all decked out in Freemason wear, an apron, their compass and ruler symbol, and a gavel. Since then one out of every three United States presidents have been members of the Freemasons. The gavel, used in our current judicial system is a major symbol of freemasonry, coincidence or not?

Also while researching I found a very mysterious Masonic connection on the dollar bill. As you can see if you circle the M A S O N and connect them with lines they create a seamless star of David, or pagan star (both common symbols of Freemason.) Also, as mentioned above, the creator of the UN and the CIA were both invented by a Mason. This may or may not be a coincidence but it sure has created some conspiracy theories that the Freemasons have been in control of the country, government and economy.

Any man can be a Freemason. He must ask to be one, Freemasons never ask you to join. They are a group based on moral systems and beliefs in God. All religions are welcome however one must have a religion. Some regard Freemasonry as a religion but they disregard that accusation. Even though the inside of their Grand Lodges look a lot like churches. Inside the lodge is an alter with a volume of sacred law and sacred books of whatever religion those masons believe in. Once you decide to become a Freemason it is a life altering commitment. It is an attempt to be reborn and become a new person, a Freemason; a good and moral person they emphasize. That sounds a lot like religion to me, or maybe it is just another coincidence.

There are three degrees of masonry; entered apprentice, fellow craft and master mason. At every level the mason will learn another secret pass code that will allow him to enter his next degree. However, this pass code must be kept secret just like everything else they learn. If you break your oaths as a Freemason you will be murdered (well at least there are historic records that support this).

This organization is based off and continues to grow off elaborate secrets.  It is hard to describe what exactly Freemasons are because a lot of it is speculative and pieced together from leaked secrets. We can however identify that the members of the largest single organization that is secret happens around the world and holds some of the most richest and most powerful men on earth. These people may or may not have dark agendas and have invisibly controlled and produced our current day society. So now when you see Freemason symbols on bumper stickers, flags, gravestones, t-shirts, buildings, etc you will know that there may be more to those images then the eye can see. It’s a society built off secrets non-masons may never know.

For more information, you can watch this documentary on the Secret History of the Freemasons

Rascals in the trash

What: I'm still on California time so I couldn't quite fall asleep when I wanted to. Feeling restless I made my way down to the beaver pond to check in on the beavers. There's a thin sheet of ice on the top of the retention pond! When I arrived one of the beavers was swimming around breaking up the ice and by the time he made it over to say hello to me it had a good chunk stuck to his fur. On my way back home I stopped by the dumpsters behind Centennial Field to see if the raccoons were feeding. I could smell popcorn as I walked up and sure enough heard rustling in one of the bins. I was greeted by three cuties filling their fat little bellies on the spoils.

As it turns out the pile of trash bags was a bit too low for the raccoons to use as a ladder to get back out of the trash cans so they were stranded in a pile of popcorn, candy, and bread - not bad by a raccoon's standards! Can't blame them for jumping in, but still poor planning. Watching them helplessly try and escape I realized two things: 1) raccoons can't jump to save their life, and 2) their front arms are strong but they can really only use them to hang on, not pull themselves up. I found this out by dangling some rope down into the dumpster so the raccoons could climb out. They were able to reach the bottom of the rope to latch onto but couldn't manage to pull their fat (and I mean really fat) bodies up. They had to swing their hind legs out to the side and grab onto another rope with their hind feet. They fell a couple of times while trying to figure out a system. I wound up putting a pallet in the dumpster to set them free. 

Ecological notes: About 3 weeks ago a couple of friends and I spotted a family of 4 feeding in the bins. Tonight I only spotted 3. One was awfully shy and hid under a sheet of cardboard. This time of year, in preparation for winter, family groups (consisting of the mother and first year kits) typically split up. This avoids competition for food during the lean winter months. In Samuel Zeveloff's awesome book Raccoons: A Natural History, he says that in colder regions, the family group will last through the winter. From what I found there seems to be disagreement over what the gender/familial relationships are within groups of raccoons. It was hard for me to tell what the gender breakdown was as males and females look the same, but I would assume that the boldest of the three was mom (pictured above, she was also the biggest), and the others were her offspring.



Where: Dumpsters behind Centennial Field in Burlington

Marcescence in beech trees

Kaleigh Wood is a senior Environmental Studies in the Rubenstein School at UVM. She enjoys exploring outside, running and cooking.

A couple of weeks ago I was on a stroll through Centennial Woods (CW) for a class assignment. The leaves littered the ground with their colors and gave my steps a pleasant crunchy sound as I made my way deeper into the woods. I looked up to find that most of the trees had shed their leaves. I kept walking and suddenly I was surrounded by this beautiful tree that was still full of its vibrant orange leaves. While I haven't taken dendrology and my tree identification skills are sub-par, I did know this one. The tree that was still holding onto its exciting leaves was an American Beech (Fagus grandifolia). I started to wonder, why do Beech trees hold onto their leaves after all the other deciduous trees let theirs fall?

I went on a run with my trusty running buddy, Lily Morgan, who happens to have a strong passion for trees. I was explaining what I had seen in CW and started to ask her what she knew about the American beech; she started rambling some things in Latin and I quickly stopped her and asked her about the leaves and why they stayed on for so long. She gave me a lesson from Reading the Forested Landscape by Tom Wessels on beech. We found out that beech and oak trees are actually somewhere in between evergreen and deciduous trees, explaining why those tree species can hang on to their leaves throughout  the winter.

We wanted to know more, we found out the genetic reasoning why Beech can hang on to their leaves, but what was the ecological advantage of it? I explored the internet and found an article in Northern Woodlands magazine. The author, Michael Snyder, (who is the Chittenden County Forester in Vermont) explained that some plants will retain dead plant matter, known as marcescence. It turns out there are many theories to the advantages of marcescence. One theory is it’s an adaptive advantage for trees growing in dry and infertile areas (where Beech trees grow!), because if they do not drop their leaves onto the ground they deprive the soil of organic matter which other trees need. Beech and oaks don't need the added nutrients so they  continue to thrive. Keeping leaves on their branches and not on the ground allows them to out-compete other species surrounding them. Additionally oak leaves are high in tannins and reluctant to decompose, further reducing available nutrients to other would-be competitors.

Other advantages of marcescence are, trapping snow which leads to more moisture at the base of the tree, the dead leaves on the limbs protect buds from frost in the winter, and finally the leaves can protect the trees from browsers such as deer and moose. The dead leaves can hide buds so they are less likely to be eaten and are more likely to grow new buds and twigs in the spring. Not only do Beech trees provide CW with great views after most trees have dropped their leaves, but there are also advantages to this interesting adaptation.

Norway Maples in the US and Centennial Woods

Posted by Maxwell Siegel- A junior in the Rubenstein School at UVM who is interested in environmental studies, and specifically sustainability studies. Forests and nature in general has always been a passion of his worth pursuing.

The Norway maple (Acer platanoides) is an extremely common species of tree across the United States, whether they line urban avenues, or make up large portions of deciduous forest. One begins to wonder, “Why is a Norway maple growing in North America?” Most Americans are accustomed to the look of the Norway maple and do not question their presence in the United States. In fact, the leaf of the species is the trademark icon for my hometown of Maplewood, New Jersey. The Norway Mmaple is the maple that suburban and urban Americans think of. But when did this species make its way from Europe to North America, and how did it become so popular and widespread?

According to the USDA Forest Service Norway maple is the most widely distributed native maple in Europe, existing in locations with elevations ranging from 0-6000 feet. The first Norway maples made it to the United States in 1756 but were relatively rare until the late 1800s when their popularity exploded. There are several reasons for the cultivation and spread of Norway maples throughout the Untied States. The first being the aesthetically pleasing color and shape the species presents, as well as its extremely immediate and sustained accelerated growth patterns. The species is well adapted to urban environments as it can withstand “moderate pollution, dusts, pavement and dry soil” (USDA forest service), making it an ideal species for lining urban and suburban streets and landscaping properties. They provide ample shade and can quickly become the centerpiece of a yard.

The true boom to the U.S Norway maple population came after Dutch Elm Disease decimated the Elms across the nation, including all of the Elm that had previously lined roads. The urban landscaping niche needed to be filled, and thus the Norway maple stepped into the batter’s box and has taken over the continent’s maple distribution and make-up. Here in urban Vermont these trees are quite common and fill their new niche rather well, making up for the disappearance of Elms along roadsides and in yards. Because they are fully capable of reproducing, the have spilled out of the concrete and are filling our forests as well. It can be estimated that Norway maples entered our state between 1860-1900 and “blossomed” between 1925 and 1950. In Centennial Woods, here in Burlington, the Norway maple thrives. It can live in varying soils because moisture is not a limiting factor. The largest Norway maple I have personally seen in Centennial Woods is in the North-Western section of the woods, and can be approximated to an age between 90-110 years old, dating it back to somewhere between 1902-1922. Another stand fills the gaps in an area that was selectively logged in the late 60s, regeneration from those first Norway maples that had since matured.

It is difficult to determine whether or not the species should be considered “invasive” or not, only because it can out compete native maples such as sugar (A. saccharinum) and red maples (A. rubrum). The diversity of maple species in Centennial Woods seems evenly distributed, however with more research a more accurate depiction of the impact of Norway maples could be determined. But that is for another time!

Holy Crows

Posted by Jess dePiano. Jess is a junior ENVS major/Ecological Agriculture minor in the College of Arts and Sciences, and is very interested in ecology and wildlife conservation.

What: Centennial Woods is a great place to observe some pretty dramatic phenological changes that are occurring as we approach the winter months. By now, pretty much all of the deciduous trees have lost their leaves (save the reluctant Norway maples), insects are few and far between, and animals are preparing for the long, cold months ahead. One amazing event that is occurring right now is a mass migration of crows flying over the Burlington area. This daily migration was first pointed out to me by one of my professors at UVM, Teage O'Connor. Seeing this migration over the past few days made me wonder: Where are the crows going? Where are they coming from? Why are they traveling in such large groups (sometimes in the thousands!)? I decided to do some research to look into these questions.

The American crow (Corvus brachyrhynchos) generally migrates short-distance during the winter months. The crows that we are seeing flying over Burlington are traveling to a communal roost (possibly near Red Rocks) where thousands of birds can be found roosting each night. This type of behavior is typical of American crows at this time of year, although to the observer, the sight of hundreds or even thousands of birds flying overhead is extraordinary.

Crow behavior is fascinating. These birds are extremely intelligent creatures, although some regard them as nuisances. Crows travel and forage for food in family groups year-round. When winter approaches, however, massive flocks form and migrate together to roosting sites, like the one here in Burlington. Over the past 60 years crow roosts have become increasingly urban and increasingly large (the largest recorded was estimated around 2 million crows). The sheer number of crows roosting together provides them with protection from predation (strength in numbers!), warmth, and the chance for adolescents to meet potential mates. Also, since crows forage in groups, belonging to such a large group may increase their chances of finding food in the winter. In an urban area like Burlington, the crows have a much better chance at finding food to scavenge and are less likely to encounter large predatory birds (compared to more 'wild' areas).

The migration is a daily one for crows, some traveling well over 10-20 miles to get to Burlington. They arrive in the evenings in a steady stream from around 3-5pm. As winter progresses, we should expect to see more of these birds migrating in the late afternoon into Burlington in search of shelter. If this winter proves to be especially harsh, crow populations may reach over five thousand. If you get a chance, take some time out of your day to watch this incredible event. I personally have never seen anything like it!

Where: Burlington, VT

Pine borers

Posted by Aaron Rosenbluth. Aaron is a sophomore from Cleveland, Ohio studying Natural Resource Planning and Economics. He loves being in the outdoors and is happily a member of the UVM outing club!

What: Two months ago I was in Centennial Woods leaning against a fallen tree taking notes. The sun was out and I couldn't have been happier listening to the summer grasshoppers sing and birds above me chirp. After almost a half an hour out there, I looked behind me at the tree I was leaning against and realized I was leaning against a phenomenon that I've seen countless times over the years, but have never really thought twice about. What I saw was a simply massive maze of tunnels/passages in the wood. The tunnels weren't very deep down - just under the bark layer - about 1cm deep, but it was a fascinatingly huge and sprawling system. I figured these tunnels were created by some sort of insect species, but which one and how and why?

After some preliminary research I quickly realized what type of species I was starting to investigate; species within the realm of wood-borers, or species which eat and destroy wood (Xylophagous species, from Greek "xylon" for wood and "phagus" for eater). These species range considerably in their characteristics (as well as richness, with over 10,000 species of wood-boring insects identified).

• All make unique patterns or “galleries” where they live and lay their larvae, 
• all produce and leave behind unique types of frass (excrement from eating wood), 
• all prefer different species of wood to bore into, 
• and all prefer different levels of health in the tree's which they choose to bore into. 

Once larvae have completed development, new adults will chew an exit hole through the bark and emerge. These exit holes are either round, D-shaped, or ovular. Typically, these wood-borers are insects and arthropod species (beetles, moths, ants, bees) whose larvae are laid in and subsequently mature under the bark layer of trees.

After realizing the tree I was leaning against was once home to massive borer community, I looked around the area (a stand of conifers, mostly white pine and hemlock) and was surprised to find that most of the downed trees in the area had once been host to this same borer species. After researching with Eiseman and Charney's Tracks and Sign of Insects and many hours of poring over internet databases, I was unable to come to a conclusion on exactly what species of borer did this, however I did come to the conclusion that it was some sort of bark beetle of the Curculiondae family within the sub-family Scolytinae (linked at the bottom of this posting is an official Vermont State report on insects which likely contains the correct species). These beetles feed on the cambium layer of trees, creating distinguishable patterns in the inner bark and outer sapwood. It is unlike bark beetles to bore deeper than 3mm into the sapwood layer of the tree, which matches what I observed in my tree. Most commonly, bark beetles will attack a tree that is already injured or diseased, often killing it in the process.

The most basic bark beetle gallery begins with the creation of a mating chamber, from which a female excavates a linear tunnel of uniform width either perpendicular or parallel with the grain of the tree (mine went parallel). On either side of the tunnel, the female creates small little niches and lays an egg in each one. I was able to see these niches in my downed tree species (these were in white pine, Pinus strobus); they look like tick marks that are evenly spread out following the main tunnel (see image above).

Ecological Notes:
Wood borers serve the ecologically keystone task of facilitating tree decomposition by creating holes and channels in the woody tissue, phloem, and bark of the stressed, diseased, or dying trees which they feed on. This allows for fungi to enter the tree and begin decomposition.
http://www.vtfpr.org/protection/documents/FullVersion2009ConditionReport.pdf