Graze On

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Goats in landscape management at German Highway. Photo by Spielvogel licensed under creative commons by Wikipedia.

I have always learned that invasive species come into an area due to imbalances in the ecosystem, such as a lack of natural predators or loss of nutrient resources necessary for native vegetation. Yet, the only solutions I ever heard were very unnatural. We could spray chemically engineered herbicide over landscapes, bring in heavy machinery to destroy anything in its path, or personally rip all the unwanted plants out of the grown. So, what about a more natural method of removing invasive plants? Thankfully, they have arrived.

Goats are the natural predators of many common North American invasive plants and have been eating them for thousands of years. Goats have evolved naturally grazing on many of the troublesome invasives that are dealt with today, such as, kudzo from East Asia or Phragmites australis from Europe [1]. The goats are so efficient because the seeds of the plants are often crushed in the goats’ grinding mouths and multi-chambered stomachs [2]. A herd of 35 goats can consume roughly half an acre of thick vegetation in only 4 days! [3]

Machinery and herbicide removal often creates additional disturbances in ecosystems. Equipment may trample or remove native, sensitive species as it takes out invasive species and herbicides can contaminate water and soil. Herbicides can also be toxic for insects who live on or eat plants, and may cause cascading imbalances in the food chain. However, the goats are able to restrict their feeding and removal to specific problems areas with fences, without leaving harmful chemicals. Once one area is done, the fences are moved and the goats graze on [1].

I often struggle to pick a side when it comes to invasive species removal. Do we pull everything out, just to see them return? Or, do we let nature take its course and leave the invasive species there? What designates a species as “invasive”? How long does a species need to be in the area to be considered “native”? But, by using goats to control invasive species, balance is being brought back into the ecosystem and the species are removed without harming native plant or animal species. Besides, I’m sure the goats are happy with the decision; they are being paid to eat multiflora rose and bittersweet all day! [1]

Watch them work! https://www.youtube.com/watch?v=Z1iZ2JkJrnc#t=69

Mary Kate Lisi is a rising UVM junior Wildlife Biology and Environmental Science double major taking part in a undergraduate field naturalist pilot program this summer.

 

[1] http://www.vtinvasives.org/news/goats-take-notorious-invasive-species

[2] http://www.eco-goats.com/why-goats.shtml

[3] http://www.bbc.com/news/magazine-30583512

If you give a monarch some milkweed

                                       1280px-Monarch_Butterfly_Danaus_plexippus_Feeding_Down_3008px Monarch caterpillar photo by Derek Ramsey and licensed under creative commons by Wikipedia.

Monarchs are one of Vermont’s most recognizable butterflies. Their distinctly patterned orange and black wings are both well known and loved; making them the state butterfly of Vermont, as well as six other states [1]. There are many commonly known facts about monarchs and their fondness for milkweed, but there are also many misconceptions.

One commonly mistaken belief is that monarch butterflies eat solely milkweed. Rather, it is the caterpillars that rely on the milkweed vegetation for food. The butterflies lay their pinhead-sized eggs underneath milkweed leaves as the foliage is the one and only plant that monarch caterpillars will eat. Meanwhile, the adult butterflies are often seen sipping on nectar from a variety of flowers.

Many people also think that if there is milkweed around, then monarchs should then be thriving. Young caterpillars actually have a relatively low survival rate when eating the milkweed, only about 3-11%. About 30% of larval losses are due to the mandibles of the caterpillar getting stuck in the sticky latex glue. Monarch researcher Stephen Malcolm wrote that a caterpillars first bite into the milkweed is “the most dangerous thing the ever do in their life”. However, some caterpillars have developed strategies to protect themselves from the latex. Some will chew through the midvein of the leaf to cut off latex flow to the area they are eating [2]. Every time you see a monarch caterpillar metamorphose, it has beaten the odds of survival.

Another misconception about milkweed is that it is only good for monarchs. In reality, there are actually dozens of other species that feed exclusively on milkweed as well, including many different types of the milkweed beetle, the cycnia moth, and the milkweed tussock moth [2]. There are also many pollinators such as bees and butterflies that use the nectar from milkweed as a food source, this in turn attracts other predators to the plant, which then attracts scavengers, making milkweed a valuable plant that contributes to diverse ecosystems.

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Swamp milkweed photo by Derek Ramsey and licensed under creative commons by Wikipedia.

It is often assumed that mowing milkweed is harmful to monarchs. However, it is actually the opposite. The chemicals given off by milkweed’s toxic latex glue allow the adult butterflies to help locate the plant and then lay eggs on it. Caterpillars absorb the toxins and become poisonous themselves. When a milkweed plant is cut down, it grows back with an even higher concentration of latex glue, so naturally butterflies tend to prefer milkweed that has been regrown. Here in Burlington, a field off of the bike path, just north of North Beach, is known as monarch meadow. The field is currently being mowed and managed to encourage milkweed regrowth and help provide a breeding area for migrating monarchs.

Stop by the field during the late summer and you might be lucky enough to catch a glimpse of the migrating monarchs!

Ben Fisher is a rising UVM senior studying Environmental Science and taking part in a undergraduate field naturalist pilot program this summer.

 

[1] Official State Butterflies. Retrieved August 02, 2016, from http://www.statesymbolsusa.org/symbol/vermont/state-insect/monarch-butterfly

[2] Eastman, John (2003) The Book of Field and Roadside Open Country Weeds, Trees, and Wildflowers of Eastern North America, Stackpole Books.

 

Newt Tales

Photo by Griffin Dahl, around a dried up vernal pool in Raven Ridge Natural Area.

While hiking below a vast dolostone face within the Raven Ridge Natural Area on the border of Hinesburg, Monkton, and Charlotte, a bright orange figure caught my eye waddling along a patch of leaf litter. The area was most likely a dried up vernal pool, a seasonal breeding pool for amphibians, covered thoroughly with wet leaves, fallen snags and mossy cobble. Captivated by its silent presence and clumsy strides, I was in awe of the fact that I had never notice this gentle forest dweller in the past. This adolescent salamander was an Eastern Newt, a complex amphibian migrating between Vermont’s waterways and the moist crevices of a typical Northern Hardwood Forest.

Breeding

The breeding process for an Eastern Newt begins during early spring, as the egg filled female searches for a mate near potential breeding ponds. The females are attracted to a male’s spots and appealing pheromones that waft through the water as they wiggle their broad tails. Males then drop sperm packets in the water, awaiting the female to pick up these packets with their cloaca, a cavity located at the end of amphibians digestive tract, in order to fertilize her eggs successfully [1]. Finally, a female will lay her eggs one at a time and scatter  them upon aquatic plants, leaving them to survive independently for around a month or two before hatching [2].  

Incubation/ Larval Stage:

These 200 to 400 jelly covered eggs now go through a 2 to 6 week incubation stage before hatching, followed by their larval stage lasting another 2 to 6 months. During this stage larvae are brownish-green and develop gills, growing to about a half inch in length. These larvae feed on small aquatic insects and crustaceans until they leave their birth ponds into the summer, lose their gills and start their first terrestrial stage of life [1].

Eft/ Juvenile Stage:

At last, the larvae develop into their juvenile, terrestrial stage where they are known as Red Efts. Efts use their bright orangish-red coloration to warn predators of their poisonous skin secretions. But don’t fear, handling these creatures is perfectly safe. Red Efts grow up to 5 inches in length and reach sexual maturity around 3 years old [4]. These juvenile efts feed on small invertebrates like snails, springtails and soil mites. Eastern Newts can survive in the eft stage for up to eight years before maturing into their adult stage so long as their habitat is sufficiently moist for survival [3].

Mature Stage:

As efts reach their mature adult stage, their skin darkens reaching a brownish-yellow or green coloration, their tails flatten, and their underbelly brightens to a yellow color with black spots. They now return to aquatic environments, searching for temporary and seasonal habitats anywhere from small lakes to marshes, though mature newts prefer abandoned beaver ponds [4]. Here they feed on immature aquatic insects, larvae and other amphibians breeding in nearby vernal pools, continuing the life cycle of the Eastern Newt for further generations to come [2]. The Eastern Newt is a delicate and often overlooked species found throughout the eastern United States, so remember next time you’re walking in the woods, especially in the rain, keep your eyes peeled for orange flashes under logs and rocks… it might just make your day.

Griffin Dahl is a rising UVM junior studying Natural Resource Ecology and taking part in a undergraduate field naturalist pilot program this summer.

 

[1] http://www.vtfishandwildlife.com/cms/One.aspx?portalId=73163&pageId=149749

[2] http://www.nhptv.org/wild/easternnewt.asp

[3] http://www.fcps.edu/islandcreekes/ecology/eastern_newt.htm

[4] http://www.reptilesmagazine.com/Frog-Amphibian-Species/Eastern-Newt/

 

Vermont’s State Musician

HermitThrush-PFEIFFER

 

“Is that a bird?” asks one of my fellow Field Naturalist Interns, as we stand on an outcropping at Raven Ridge Natural Area on the border of Hinesburg, Monkton, and Charlotte, Vermont. When I told him that the song he was hearing was that of the Hermit Thrush he said that he had “never heard a bird sound so much like music”. I had never really considered the musical elements of birding before this comment and then felt compelled to look into the compositional stylings of the Hermit Thrush.

This medium-sized member of the genus Catharus (which also happens to be the state bird of Vermont) sings a song that is perhaps that most magical string of notes I have ever heard. Being somewhat of a musician and much more of a birder, I love listening to the song of the Hermit Thrush with its melodic, tumbling trills, like a flute harmonizing with itself. According to a number of auditory studies, the notes of the song of the Hermit Thrush are related to each other by pitch ratios that differ by simple integers of harmonic notes [1]. This discovery highlights the fact that the song is more similar to music produced by humans than to the songs of other birds that have also been studied in this way. It is also noted that certain harmonies produced by the Hermit Thrush are in line with those made by human music [2]. On top of all this musical jargon, it has also been discovered that this bird could be capable of producing other notes in its song, meaning that the species chose to sing in such an ethereal harmony.

You don’t need to have a musical background to appreciate the sounds of nature, the birds singing, the creaking of young trees as they sway in the wind, the croaking of a distant frog, or a stream gurgling and dripping down a mountainside. Among all of these sounds, however, nothing resembles music quite as closely as the song of the Hermit Thrush.

Hear it for yourself! https://www.allaboutbirds.org/guide/Hermit_Thrush/sounds

Emily Hamel is a rising UVM senior and Wildlife Biology major taking part in a undergraduate field naturalist pilot program this summer.

 

[1] https://www.newscientist.com/article/dn26498-thrushs-song-fits-human-musical-scales/

[2] http://www.smithsonianmag.com/science-nature/birds-songs-share-mathematical-hallmarks-human-music-180953227/?no-ist

 

The Colors of Faoilleach

We’re in the middle of faoilleach – the Gaelic season comprising the last three weeks of winter and first three weeks of spring. Before you groan over the absence of green, and wish yourself in the lime lighting of a June forest, take time to notice and celebrate other colors that hint to the great awakenings of spring.

Magenta

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Beneath their pearly coats, the emerging catkins (spikes of single-sex, drooping, petal-less flowers) of the pussy willow glow magenta. Their presence is a cherished ritual of the seasons, Sigurd Olson writes, “In a world seething with mistrust, suspicion and clashing ideologies, pussy willows may be vital to the welfare of man and his serenity”.

Burgundy

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Look for the deep burgundy color in the male catkins of speckled alder as their flowers begin to develop. As the male catkins begin to expand, the color brightens. Eventually the burgundy shifts toward yellow as the pollen develops. Note the smaller scarlet female catkins nubs above (these will transform into the cone-like structures that persist throughout the winter).

Ivory

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Ivory hairs gleam in newly opened shadbush buds. They help insulate the flowers from spring cold snaps. Soon clusters of 5-petaled propeller-like white flowers will emerge. The flowering time is an important seasonal clock – marking when shad swim upstream to spawn (hence the name) and the period when colonists who died over the winter were buried, hence another name—serviceberry.

Auburn

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Look for the bursting auburn flowers of silver maples lining streets and rivers, especially noticeable against a bluebird sky. This fast-growing and short-lived species carries its male and female flowers separately, although sometimes on the same tree.

Silver

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Catkin tips shine silver as they emerge from flower buds of trembling aspen. Male and female catkins are found on separate trees. Despite millions of fluffy seeds produced, strict germinating constraints limit the success of these seeds. Thus aspens rely on root sprouting clones to earn their title of most widely distributed tree in North America.

Crimson

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Spring sun vividly reddens Red Osier Dogwood in early spring. The brilliance of color, generated by anthocyanin pigments in the bark, is determined by light intensity. In shaded areas, its stems and branches still grow, yet in greener tones.

If you’re impatient for the mints and emeralds, limes and jades, you can force the color. Simply place a twig in a jar with water near a window and be comforted by the return of green that will reveal itself outside in time.

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Ellen Gawarkiewicz is a first-year graduate student in the Field Naturalist Program.

Mushrooms in our Midst

They rose up from the ground like golden fingers, grasping the earth of the Northern White Cedar Swamp. Once aware of their presence, I began seeing their relatives everywhere. Black tongues sprouting from stumps, miniature sheets of rolling parchment across a log, raisin-like swellings on branches, delicate feathers and elegant goblets along fallen trees, a smear of blue paint on a stick, a white parasol shading decaying leaves.

How are they alike? They are all mushrooms. Around this time of year, especially after rain, you see them bursting forth from the leaf litter and colonizing fallen logs.

Golden Spindle (Clavulinopsis fusiformis)

Golden Spindle (Clavulinopsis fusiformis)

Mushrooms are the fruiting bodies present in some fungi—like the apples of a tree. The fruiting bodies contain spores that produce new fungi, similar to the seeds in fruit. The rest of the fungus, called the mycelium, is often underground.  It’s made up of a network of fine filaments, also known as hyphae. These filaments resemble the roots of plants, but unlike roots, hyphae actively digest their surroundings. The mycelium portion of fungus can be massive.

Turkey Tail (Trametes versicolor)

Turkey Tail (Trametes versicolor)

In a single cubic inch of soil, there can be more than eight miles of these cells – around 300 miles of mycelium to a footprint. In fact, the largest living organism is a fungus – a single individual that has colonized an area roughly 2,400 acres in eastern Oregon. That’s 1,665 football fields. Fungi are also powerful; the mushrooms of one fungus, Coprinus comatus, develops with such ferocity that it has been known to break through asphalt. Another fungus, Pilobolus, blasts its spores at a force of 20,000g—more than double the acceleration of a bullet from a vintage rifle.

Crowded Parchment (Stereum rameale)`

Crowded Parchment (Stereum rameale)`

Fungi aren’t plants – they’re actually more closely related to animals as their cell walls have chitin (a tough substance also found in the exoskeletons of insects and crustaceans). Fungi are decomposers, breaking down plant tissue and other materials. However, many fungi get an extra boost of nutrition through a symbiotic relationship with a host plant. In exchange for a renewable food source, the fungi provide mineral nutrients and water taken up by their incredible surface area. 95% of examined plants obtain nutrients and water through a relationship with fungi. Some fungi are saprophytic, feeding on dead or decaying organic matter in the soil and making room for new growth. Some are parasitic, feeding off of living tissue.

Humans have appreciated mushrooms throughout history. A 5,300 year-old Tyrolean Ice Man, Otzi, was discovered frozen in ice with a satchel of Tinder polypore (Fomes fomentarius), along with Birch polypore (Piptopurus betulinus). Perhaps they were used as a fire starter, or maybe for its antibacterial properties, or possibly to ward off insects or evil spirits.

Black-footed Polypore (Polyporus badius)

Black-footed Polypore (Polyporus badius)

Today, fungi have a wide range of uses– decomposable packaging, insect extermination, antibiotic production, and contaminant mitigation. In addition, mushroom burial suits have been developed to facilitate the process of human decomposition while cleansing the body of accumulated toxins

Even if you don’t want to be buried with a suit embroidered with spores, there are plenty ways to appreciate fungi. Go out this autumn and relish the myriad of mushroom forms. Contemplate the vastness of mycelium under your feet and how it supports the life growing over your head.

Ellen is a first year student in the Field Naturalist Program. 

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