Of Woodchucks (and Lawns)

Lawns.  I am not a big fan of them.  I love meadows, or even lightly tended fields.

Summer rain over a Vermont field full of buttercups (Ranunculus spp.)

I prefer to have a yard rather than a lawn, that flat expanse of close trimmed grass we call a lawn has never been all that appealing to me.  A “yard” does not carry the implication of maintenance that a “lawn” implies.  Lawns are an integral part of American life though, and are found even in places completely unsuited to their presence.  In some areas neighborhood associations mandate how your lawn must look, what you can and can’t have on it, and, in extreme cases, what shade of green it must be and how many inches tall it must be.

There are many theories behind why lawns exist, some people claim that it is a relict of animal husbandry, particularly sheep and how a grazed landscape looks.  Others claim that it taps into some deep species memory of living on a savanna, that the flat, open land is visually soothing and  provides a sense of safety and removal from danger and the unknown.  Some claim that lawns are a symbol of our control over nature, our own private, manufactured landscapes.

The most interesting idea I’ve heard for the prevalence of lawns in the US is in Charles C. Mann’s excellent book 1493: Uncovering the New World Columbus Created.  He suggests that wide, expansive lawns may have been an anti-malaria survival strategy.  A house on a rise on the landscape with cleared land around it would catch the breeze and prevent malaria carrying mosquitoes from getting into the house.  Lawns became embedded in the social consciousness of the emerging United States and spread with the population, as symbolic as the flag or fireworks, though more subtle and having greater practical value.  It is an interesting idea and makes as much, or more, sense as any other idea concerning lawns that I have read.

What bothers me about lawns is that they tend to be uniform monocrops with little three-dimensional texture.  This lack of diversity limits what wildlife visits a lawn, and I, as an ecologist and someone who is always investigating things, love diversity.  My yard here in Vermont is diverse, but my landlord likes a short lawn and cuts it down to an inch or two in height.  Every time he does so all the insects, birds, and mammals flee, taking weeks to return.  I like all those mobile visitors.

Dew covered Funnel-Web or Grass Spider webs (Agelenopsis spp.)

One of the visitors to my lawn is a plump woodchuck (Marmota monax).  It only crosses the road to my lawn when the vegetation reaches 6-8 inches, then it visits nearly every evening and some mornings a well.  This rotund fellow is wary and alert, standing up and peering about at the slightest out of place sound.

Woodchuck (Marmota monax) alert for danger

The name Woodchuck is actually a derivative of a Native American name wuchak, and has nothing to do with either wood or chucking, despite generations of woodchuck chucking wood tongue-twisters.

Woodchucks, also known as Groundhogs, Land-Beavers, and, my favorite, Whistle-Pigs are marmots, large rodents related to ground squirrels.  Most of the marmot family are alpine dwellers, commonly found in high grassy places from Europe to Asia and through North America, but the woodchuck is a lowland species wide-spread in the northeastern and central United States, and through Canada up to Alaska.  Like other marmots woodchucks have a piercing alarm call, a sharp whistle that carries far, sometimes with a bit of a burbling quality to it.

Woodchuck from the rear

Most often a woodchuck will appear as a furry lump on the grass, something like a cross of a loaf of bread, a caterpillar, and a fat otter pretending to be a cat.  Many people have a particular dislike for woodchucks because they eat garden vegetables and ornamental plants.  A good friend of mine has been driven to distraction by one that is eating her hydrangeas.  The one that visits my lawn (but only when it has not been cut for a while) eats the dandelions and fleabane, basically weeding the yard for me.

Woodchuck eating weeds from my yard

During the spring, summer, and fall woodchucks pile on as much fat as they can, much like small bears.  Come winter they retreat to a specially dug winter burrow to hibernate.  Marmots are some of the few animals that enter true hibernation.  They radically slow all their metabolic processes and remain oblivious to the world until mating time, often beginning in February or March, possibly later the further north they live.

Woodchucks have marvelously thick and soft fur, as do other marmots.  I have a hat I bought in western China with a marmot fur ruff that is too warm for me to wear in nearly any weather.  Despite putting on a tremendous amount of fat their flesh is lean, most of the fat is in a subcutaneous layer, just beneath the skin, with the rest stored in the body cavity between the internal organs.

Woodchucks are the most solitary of marmots and are said to be aggressive.  They can be hand raised to be cuddly, but it takes a great deal of effort to overcome their feisty nature.

Surprisingly, woodchucks are reputed to be agile climbers in an emergency, though I have yet to see one scale a tree.  Most often what I see is one popping up to look about:

Wary woodchuck watches for danger

Followed by a rapid retreat if I am not careful, quiet, and slow moving:

Just too dangerous around here…

I like this occasional visitor to my yard, and, given the option, do not mow my lawn as if I do it will not come by to visit.

Mainly because it is silly – if the animation is not working, click the image

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A note:  my posts may become a bit erratic for a few months, I am in the midst of finishing one job, moving (maybe twice), and will hopefully be beginning a new job in a different country.  Eventually this will provide great material for the ongoing exploration of nature, but the route there may be a little irregular and unpredictable.  Bear with it, I will not abandon my writing and photography.

Chickadees, survivalists extraordinaire

It seems likely that weather is the only killer so devoid of both humor and dimension as to kill a chickadee.”

Aldo Leopold wrote this line back in 1949 in his incredibly influential book, A Sand County Almanac.  He was commenting on the extraordinary longevity of chickadee 65290, a bird that had survived for at least 5 years following its banding in 1937.  Little 65290 may have been extraordinary, but a brief walk in the winter New England woods will rapidly convince you that chickadees as a group are exceptionally resilient little creatures.

Chickadee in the spring sun

Chickadees are very vocal, calling to each other throughout the year. You can hear some of their calls at the Cornell Bird Lab website.  Chickadees often travel in loose flocks, flitting about, hanging upside down from branches, stealing insects from spiders, scrounging for seeds, and chasing each other about in the forest like a group of excited 5 year old children just released from a long, boring bus ride.  Their colors are subdued, yet distinctive: black, gray, white, often with a hint of yellow or tan on their underbellies.

Chickadee acrobatics

Black-Capped Chickadees (Poecile atricapillus) are cold weather specialists with a home range extending from Alaska to New England and dipping as far south as the mountains of Arizona and New Mexico and along the spine of the southern Appalachians (map).  I find this is extraordinary.

There is a principle of physics called the square-cube theory that relates the volume of an object to its surface area.  Basically, this can be simplified to the idea that a mouse has more surface area compared to its volume than does an elephant, and that for every time you double the size of an object its mass goes up by eight times (Length x Width x Height).  In terms of survival in cold climates this is really important because smaller things lose their heat far faster than large things because of that ratio of surface area to volume.

Chickadees are tiny.  Their bodies are barely larger than a golf ball, and much of that is feathers.  All told they probably weight as much as an emaciated mouse, yet they live in a part of the world that is well below freezing for great portions of the year.  During the winter nights chickadees huddle in cavities in trees in semi-torpor, burning fat at a prodigious rate.  At first light they are up and spend the day searching for food.

Feeding Chickadee silhouette

All living things have to balance the payoff of their behavior with the potential risk that behavior carries.  Some species are extremely risk-averse, in political terms these species might be the Ron Paul’s of the world, insisting on a gold based currency.  Chickadees are the opposite, they are inquisitive, curious, bold, and fearless.  As in many animals, their willingness to take risks is dependent on availability of resources.  You see this in humans, a far greater proportion of low income people spend their money on lottery tickets than high income people, despite the abysmally low chance of getting a winning ticket.  If you have few resources you will take more risks to get a large reward.  The costs of those risks are higher for those with fewer resources as well.  For chickadees this means of food and a place away from that humorless weather.

Keeping warm in winter takes more food than in summer, and food is more difficult to find.  Chickadees take risks to get that food, they investigate new objects almost as soon as they encounter them, they come closer to humans and stay longer than many other birds, and they try new things.

Traveling in groups is one way to offset the individual risks these brave little birds take.  More companions means more eyes to watch for danger (and food as well), and chickadees have a very well developed warning system that alerts their companions not only to danger, but to the degree of danger.

The risks they take, their small size, and the harsh weather they endure takes its toll and chickadees do not live long, hence Aldo’s comments on chickadee 65290.

Chickadee and hungry young

Chickadees may not live long, but their lives seem bright and full of vibrancy.  They are a reminder of the importance of curiosity, companionship, and communication.

Bryophyta, Ancient and Tough

An ancient creature is waking up.  These creatures are small in stature but extremely tough.  They have been around longer than plants, although we often lump all green sessile things together.  Mosses are different though.

They have neither roots, nor vascular tissue, the plant equivalent of our circularity system.  They anchor to the substrate with little hold-fasts, somewhat like those giant algae, sea-weeds, and they drink though diffusion and osmosis.  They do well in places that are rich in airborne moisture.

Another things mosses lack is flowers and the associated seeds.  Like ferns, club-mosses, horsetails, and fungi mosses reproduce by spores.  By the millions.  They invest in quantity over quality and don’t pack any food or protection for their offspring before they cast them to the wind.  The spores will only germinate under perfect conditions.  Orchid growers are familiar with this problem, as orchids try the seed equivalent of this strategy.  Their dispersal strategy is like colonizing the galaxy by putting people in zip-lock bags and flinging them out of the solar system in the hopes that one of them eventually hit an earth-like planet.

This time of year the capsules that held the spores look like fossilized wind-socks.

Mosses are incredibly tough and individual stems from a colony can be very long lived.  A common way of judging the age of stair-step moss is the count the feather-like branches on a stem.  Five and seven year old moss stems are common and there are other mosses much longer lived than that.  An established moss colony may been in place for thousands of years.  Especially colonies in cold environments.

In the northern hemisphere we tend to think of plants and animals going dormant in response to cold.  If you can prevent the water in your tissues from freezing the danger for plants becomes one of dehydration.

Mosses, as I have said, are tough.  And Ancient.  They have some tricks they have learned over the hundreds of millions of years they have been around.  They learned these tricks before the ancestors of most of the things we see around us evolved.  Dinosaurs are latecomers to the party by the standards of the mosses.

Mosses dry up.  In a way the lessons learned as a spore transfer to the adults.  Most of their water evaporates, and as it does so the moss tissues curl in predictable ways.  The pores through which they breath close. Mosses can wait a long time like that.  Some mosses are so good at surviving this way that they grow in deserts.

Air in cold environments often contains less moisture than desert air.  Vermont has been even dryer than usual and many of the fir-cap mosses are still tightly furled, waiting for water.  Many look like the dry spires in the picture above.

Others have found enough water to wake up.

Like sponges, moss colonies trap water and fine debris.  The debris falls to the ground in the suddenly still water and becomes a nutrient supply for the mosses once they rehydrate.  Much like flowers they open as their tissues fill with water.

The growing tip opens as it hydrates revealing a tight furl of nascent microphylls (moss and clubmoss leaves) tinged a rosy hue.  Cold is well and good for living slowly, but growth requires warmth and the tips of the moss are shaped like little parabolic reflectors.  They trap both water and the sun’s light.  The reddish color may help them adsorb the long-wave understory light once the forest above leafs out.

From now through summer the new spore capsules will ripen, and come fall and winter they will scatter their spores across the landscape to drift with the wind, flow with the water, and run across the snow.

Unlike the poor fellows in zip-lock bags hurtling between the stars, the mosses have stacked the odds a little for their offspring.

Where water splashes moss may grow.  Where wind dies and lets drop what it carries moss may grow.  Where snow is late to melt moss may grow.

NOTE: The three close-in photos were taken though a 10x hand-lens held to the front camera of an iPhone4.

Water in Winter

Water in winter is a precious commodity.  At first thought, this doesn’t make a lot of sense, here in Vermont the ground is covered in snow, which is, after all, merely water in a specific phase state.  Despite this being a meager winter in terms of snowfall, there is between 1 and 8 inches of snow, depending on where you are, on the ground near my house in northeastern Vermont.

The problem is three fold, 1) that phase state issue.  Snowflakes are delicate ice crystals, and ice has a Mohs hardness of around 1.2-2 at normally cold temperatures.  This is harder than chalk and talc.  Ice acts as a soft rock.  2) Humidity, the ability of the atmosphere to hold water is dependent on temperature.  The same relative humidity at different temperatures means very much less total available water at a colder temperature.  At cold temperatures things dry out quickly, which is part of the reason deciduous trees drop their leaves, and why other plants cover their leaves in waxy coatings or thick layers of hair.  3) the ground is frozen, locking up surface water and making it unavailable to plants and animals.

These factors combine to make winter a stressful time for plants, but for animals the cold makes it even more difficult.  Animals have several options for dealing with cold; they can hibernate, dropping their temperatures and metabolic needs to a bare minimum and wait out the difficult times; they can insulate themselves with layers of fur or fat to protect from the cold; or they can ramp their metabolism up to generate more heat.  The problem is that generating heat via metabolic activity takes water… where do you get it in the winter?

Today was a warm winter day in my portion of Vermont, somewhere in the high 20s, and the snow had melted away some since the last snowfall.  About 50 feet behind my house I came across the tracks from a fisher that had been hunting several days earlier.

Being inquisitive, I followed the tracks.

In typical mustelid fashion they wandered semi-randomly across the landscape, but, as I followed them, more and more tracks came together, making a veritable highway of frozen tracks in the snow.

More and more tracks came together, both of fisher and of deer, coyote, and bobcat.  Clearly I was onto something, but what?

At first, when it was just fisher tracks, I had been hoping to find a den.  If I could find a den, I might be able to justify finally buying a game camera, something I have wanted for a long time.  I found a dead sugar maple that might be a den, but as I continued exploring, that was not where the greatest number of tracks was.  Maybe I would find a kill site.  A scattering of porcupine quills or several puffs of squirrel fur.

Nothing of the sort greeted me, but what I did find was a small frozen pond fed by ground water and surrounded by tracks and scat from all sorts of animals.

Ground water, that is the key.  The earth has tremendous thermal mass.  Thermal mass is a sort of battery or reservoir of heat (there really is no such thing as cold, it’s all varying degrees of heat, with no heat being 0 kelvin, or absolute zero).  In my region of the US the ground stays at a relatively constant 50 degrees F.  In the hot and humid summers that means all the rocks sweat, condensation forming on their (relatively) cold surfaces, and well water is refreshingly cool to drink and chilly to bathe in.  In the winter this means that seeps and springs stay running and liquid all winter, and well water feels deceptively warm (though still chilly to bathe in).

The fisher I had been following was heading to a source of water, water that drew numerous other animals, including a bobcat that left scat at the base of a hemlock tree and probably hunted the other animals that came for water.

The fisher I had been following, and, perhaps several others, has spent quite a lot of time at this pond.  The tracks were melted into the ice all around where the liquid water came into the pond.

Even in a place as water rich as Vermont, water can still be a precious commodity.