Nature Blog

Ripples 12/5/19

By Jessica Johnsrud, Education Coordinator

Walking in my neighborhood was quite picturesque the morning after the recent snowstorm. Branches on the evergreen trees swooped low, heavy with snow and ice. Maple and birch trees stood tall and bare, encrusted with ice and snow along the bark and branches. They looked like sparkling skeletons against the soft blue sky.

photo of trees with snowTrees are an important part of our landscape. There are two main types of trees: coniferous and deciduous. Deciduous trees have broad leaves that change color in autumn and shed before winter. Red maple, black cherry and white birch are a few examples of deciduous trees that grow at Woodland Dunes. Deciduous trees have thin leaves, and the water inside the leaf cells would freeze in the cold winter. Water expands when it freezes and would rupture the cells, causing damage. Deciduous trees drop their leaves in the fall as a winter survival strategy.  

Coniferous trees, such as white pine and eastern hemlock, grow cones for reproduction and have needles or leathery, fern-like leaves. The needles have a waxy cuticle or coating that retains moisture and protects from freezing during the winter. Some produce an antifreeze that is concentrated in the cells to prevent freezing. Over the course of time, old needles drop and new needles grow. Most conifer trees are green year-round, however there are exceptions to every rule. The tamarack is a conifer tree, but every fall its needles turn golden yellow, then fall off.

Trees provide habitat for wildlife, but also offer extremely important ecosystem services. They clean the air, absorb rampant carbon dioxide, provide oxygen, prevent erosion, supply food and cool cities and streets. Interestingly, trees also heal. Research has shown that patients recover faster and with fewer complications if they have a view of trees from their window. Children with ADHD show reduced symptoms when they spend time in nature. Neighborhoods with trees have lower incidences of violence than neighborhoods that don’t have trees or have few trees. Doctors in the United States are even prescribing “park prescriptions” to their patients, encouraging them walk in a forest or park for a specific amount of time.

About 30% of Earth’s land area is forested and I am grateful to live in that 30%. Trees are an important part of our landscape and truly benefit everyone. They also make my walks in all four seasons, more interesting.

Photo taken at Woodland Dunes by Nancy Nabak

Ripples 11/28/19

Written by Jessica Johnsrud, Education Coordinatorphoto of a wintery sunrise

Early in the morning, I often walk along Lake Michigan to take in the sunrise. I enjoy this quiet time and like watching how quickly the colors of the sky change as the sun makes its appearance for the day. There have been some pretty dramatic sunrises, and sunsets, as of late. From pastel pinks, blues and yellows to intense indigos, fushias and fiery oranges, they have been incredibly stunning.

The sun’s rays contain all the colors of the visible light spectrum: red, orange, yellow, green, blue, indigo and violet. Perhaps your elementary school teacher taught you to remember the colors and the order by learning the acronym ROY G BIV. Together, all the colors appear as white light. Light energy travels in waves and each color has a different wavelength. Blue and violet light are shorter waves and red and orange are longer waves. This is observed when sunlight travels through a prism and the white light is separated into all of its colors.

As the sun’s light enters the atmosphere, it interacts with water and ice molecules in the clouds, and dust and other particulates in the air. These obstacles in the atmosphere deflect and diffuse the light waves. This is known as scattering.
Blue and violet have shorter wavelengths, so are scattered more easily than the other colors. This is why the sky appears blue on clear days.

In the morning and the evening, when the sun is low on the horizon, light rays must pass through more atmosphere. This means the blue and violet light scatters, but since the light has to travel further, blue and violet scatter out of the line of sight and become very faded. This leaves the longer wavelengths of the light spectrum, red, orange and yellow, visible and explains why sunsets and sunrises are often magnificent reds and oranges.  

Red has the longest wavelength of all visible light and is why the sun appears crimson when it’s on the horizon. The light has to travel through so much atmosphere, that all other colors are scattered and just red is visible to our eyes.
Sunrises and sunsets are a welcomed part of each day. For some people it may signify a new beginning, for others it’s a reminder to slow down. I like sunrises and sunsets because they are free and can be enjoyed by everyone.  

Photo taken by Jessica Johnsrud 

Ripples 11/22/19

Thanksgiving

photo of high bush cranberry

highbush cranberry

The years certainly fly by, and sometimes it’s hard to comprehend their passage. Forty five Thanksgivings ago a group of local people decided there would be a Woodland Dunes, and took steps to buy land and organize environmental education programs. Their decisions were driven by a desire to help nature and teach about it, not the desire for financial gain. They raised funds and purchased wooded swampland near Lake Michigan – land that couldn’t be farmed and shouldn’t be developed, yet was full of wildlife and accessible from both Manitowoc and Two Rivers. The land had seen many uses from pasturing, to mink farming, to logging and hunting, to some farming. Released from those uses, it quickly rebounded into the shrubby and forested wetlands that originally covered the ground. Tens of thousands of birds were caught, banded, and released. From this we learned how important are the habitats along Lake Michigan to migrating wildlife. Few people realized that saw-whet owls migrated through here until our banding efforts revealed hundreds moving through each fall. We are thankful that our founder and those who helped him had the foresight to purchase the land, establish the preserve, and develop programs that would help educate hundreds of thousands of people.

We are thankful for all the people who have come forward to help – from those involved in the formation of the organization to those who continue to come forward to teach, maintain, and financially sustain our place.  About 300 people each year volunteer to help, and there’s no doubt that we could not run Woodland Dunes without them.  Our small staff would only be able to provide a fraction of what it takes to manage a 1,500 acre nature preserve while providing programs for more than twice that many people.  And  still do a bit of wildlife research so that we can track what lives here.

But most of all, I am thankful for the wildlife itself. Even though the chickadees that actively visit the feeders look lively and happy, theirs is not an easy life.  And people seem to continuously make things more challenging for wildlife: fragmenting the forests, eliminating wetlands, introducing unfamiliar foreign diseases, plants, insects, and chemicals into our habitats- even changing the climate itself.  Wildlife always pushes itself into new territories and beyond its comfort zone.  There are a number of animals that  I remember from my youth that used to live here. Sadly, they are no longer found here.  As a result, every northern shrike or sandpiper or gentian flower or weasel seen in the woodpile is a cause to be thankful. From our experience, if you give wildlife a chance it will often respond. Hopefully, that’ll be the case until we fully get our act together in terms of our environment.

The good news is we are coming to realize that what is good for nature is good for our nature as well. Where do we like to spend free time when we need to “recharge”?  Often it’s by the Lake, or heading “Up North.”  We fish, hunt, walk, bike, swim, and feel better for it. We need to appreciate that, be thankful for it. We are powerful, and more than ever have the ability to take better care of the land and water that sustain us, and the living things that share our surroundings. In doing so, we can make our Thanksgivings more happy and full of gratitude. 

photo- wild American highbush cranberries at Woodland Dunes

Ripples 11/14/19

Unlike many years, judging by the average daily temperatures, this winter was thrust upon us. It seems we missed out on those wonderful late fall days with temps in the mid-40’s when the woods are awash with colorful fallen leaves. They may return, but right now the world is prematurely snow-covered. A week ago, there was still a chipmunk under the bird feeder – I’m sure gathering seeds to be stored in its subterranean home for later snacking.  Now it’s gone – perhaps sleeping on top of its larder.  One wonders if such animals will feel the effects of the shortened gathering season later on.

photo of tree sparrow on branch

American tree sparrow

One always wonders about the birds, too, and how they manage to stay warm.  There are still some fall migrants around, like white-throated and song sparrows- hardy little birds which tolerate a lot of cold.  And tree sparrows are yet to come.  It turns out there are a number of things birds employ to stay warm in the winter.  

First, birds are warmer than we are.  Their body temperatures average 104 or 105 degrees F.  Combined with their generally smaller size and greater relative surface area, they have to work hard to maintain those temperatures.  Small birds like chickadees start shivering when the outside temperature is about 65 degrees. The movement of their muscles generates heat, and they will shiver the whole winter through.

We all know that birds have feathers – that’s one of the things that defines them. Feathers are amazing structures that give birds their streamlined shape, insulate them, repel water, and create displays to potential mates. How many feathers do birds have?  Small songbirds have usually 1,500-3,000 feathers that are molted and replaced as they wear.  The average bird has probably from 3,000 to 5,000 feathers. Large birds, like swans, have upwards of 25,000. Birds spend a lot of time tending and maintaining their feathers so that they function properly. They also molt and grow extra feathers in the fall.

Birds also have the ability to restrict blood flow to their legs and feet – preventing hypothermia.  Even though they can do this, watching ducks in cold water in winter still makes me shiver. The scales on their legs also help to prevent heat loss. Many owls, on the other hand,  have well-feathered legs to help them stay warm. Birds can fluff out their feathers, trapping air beneath them to provide extra insulation. On very cold days, this gives birds a puffy, swollen appearance.  

Birds  metabolize fat quickly.  They store calories taken in from the sunflower seeds that we put out as fat. They can draw down their fat reserves quickly, also. If one catches birds for banding, one can sometimes see the change in fat reserves on a bird from day to day if the same bird is re-caught.  

Some birds, including chickadees, go into a lower metabolic state at night called torpor. They aren’t actually hibernating – their metabolism drops just a bit, so they use less energy to make it through to morning.

Birds also adopt certain behaviors in winter- they find sunny places which are warmer and utilize dense vegetation to get out of the wind. (It can be significantly warmer under the boughs of a spruce tree, and some birds huddle together to share the warmth- chickadees are known to do that at night.)

The native trees and shrubs we planted help protect the songbirds in our yard during winter. The bird feeding area at Woodland Dunes is ringed with plants that shelter birds as they come in to feed. Offering high-quality foods like black sunflower, suet, and liquid water also makes things easier for birds in the winter.  They are ingesting good nutrition and spending less energy than required to obtain water from frozen snow and ice. Birds have the tools to make it through the longest winter, and with a little help from us will generally do just fine.

The first tree sparrow showed up at the feeders today.  Welcome back.

photo- American tree sparrow by Mdf from Wikipedia. 

Ripples 11/7/19

If you own a dog, you are assured to get outdoors in all kinds of weather and at all hours. I am one of those people and am sometimes less than thrilled at these excursions, especially when they happen in the middle of the night. At other times, I see things that I would not otherwise notice. I’ve written about this before, but I am so frequently reminded of the value of these little canine excursions that I think they bear further mention.

Lately, owls have been more apparent both at home and at Woodland Dunes. Even though they are not breeding this time of year, screech owls owls are calling and are more noticeable, perhaps because the nights are longer and I am outside more in the dark.  Actually, they never really seem to stop calling, but in summer seem to produce their quiet, tremolo call more than their full-fledged screech or whinny. Their eerie vocalizations are especially appropriate around Halloween, and I wonder what they think my little companion and me out for evening or early morning rounds. Great horned owls are vocal now too, as this is their courtship season. Theirs is a booming call that carries for long distances, with males calling at a lower pitch than females.

robin in snow

Any time that it’s not completely dark there are birds at or beneath the feeders – cardinals especially seem to be present when the light is low. Juncos are back, but there are still white-throated, song, and fox sparrows lurking in the weeds.

Lately, during the daylight hours, there have been robins everywhere, and it’s been that way for several weeks. This morning, despite the onset of another early-season snowfall, the very first bird to be heard was a robin, followed by a mallard duck. I live in a neighborhood with many crabapple trees which are wonderful sources of bird food. There are also thousands of common buckthorns – an invasive plant from Eurasia which also produces berries which birds consume. Eating buckthorn berries causes digestive problems for animals, to put it delicately.  The buckthorn berries and their seeds pass through the robins rapidly, so the birds are a great source of seed distribution for the invasives. And they seem to sprout everywhere. They must supply just enough nutrition to keep the robins in the neighborhood, at least until the real cold arrives.  Then the robins will move south just far enough to feel they can tolerate the winter, many just a few days flight south of here, ready to return when spring does. The less-hardy birds go to the Gulf coast  or even central Mexico. They are not the same birds as are the robins of Europe- those are smaller and lighter-colored members of the flycatcher family, while ours are thrushes.

We usually think of robins eating worms on the lawn, but there certainly won’t be any worms around here for those birds who choose to stay all winter.  Really, most of their diet consists of fruit and insects, although worms are certainly a favorite when available, conveniently right around nesting time. And all of those crabapples, berries, and bugs help to sustain a species whose numbers are estimated to be about 320 million birds, almost as many as there are people in this country. Unlike us though, they have to watch out for hawks, stray cats, and windows to survive.  

Seeing robins when the world is snow-covered is a treat, and even though we’re just starting winter, a sign of things to come.  In the meantime, I’ll appreciate their hardiness, and look forward to the next interesting encounter with them on these little but necessary walkabouts.

photo- American robin by the Weather Network