Vernal Equinox 2016

Early Spring iris blooms in my garden (16 March 2016)

Yesterday at 12:30 AM (EST), Spring officially began for the Northern Hemisphere.  The date of the switch from Winter to Spring is known as the Vernal (Spring) Equinox.  On this date, the sun crosses over the celestial equator and begins to strike more directly on the Northern Hemisphere than the Southern Hemisphere.

If you were to rise each morning and observe the location of the sunrise from the exact same spot, you would find that the sunrise takes place in a slightly different location from one day to the next.  On the first day of Winter the sun would appear to rise far south of due east.

As winter progresses, the sun's position moves northward along the horizon a little bit each morning.  It will continue to move northward until the first day of Summer.  At that point each sunrise will move south along the horizon until the first day of Winter arrives again.  On the first day of Spring, the sun rises midway between these northern (Summer) and southern (Winter) maximums - the sun also rises at the midpoint on the first day of Fall (Autumnal Equinox).  Sunsets follow a similar pattern in the western sky. 

This shifting of the sunrise (and sunset) is due to the fact that the earth's axis is not directly perpendicular to the plane of its orbit.  If the earth's axis were perpendicular to the plane of its orbit, the sun would rise and set in the same location each day.  Instead the earth's axis is tilted approximately 23.5 degrees from the vertical - this is why globes are tilted.  For part of the year the Northern Hemisphere is tilted toward the sun (Spring and Summer) and for part of the year the Northern Hemisphere is tilted away from the sun (Fall and Winter).  Conversely, while the Northern Hemisphere is experiencing Summer the Southern Hemisphere is experiencing Winter; while the Northern Hemisphere is experiencing Winter the Southern Hemisphere is experiencing Summer.

Not only are the locations of the sunrise and sunset shifting, but the amount of daylight and darkness is also shifting.  On days when the position of the sun moves further north the amount of daylight grows slightly longer.  On days when the sunrise shifts southward the amount of daylight decreases slightly.

There are only two dates on which neither the Northern nor Southern Hemisphere is tilted more toward the sun.  On the equinoxes, both the poles line up with the direction of the earth's orbit and both hemispheres receive approximately equal amounts of daylight and darkness.

We are expecting snow later this week, but it officially Spring.  Get out there and enjoy it!

Snakes - A St. Patrick's Day Tradition

It's time for my St. Patrick's Day tradition - sharing a photo of snakes.

A Northern Water Snake training for the future invasion of Ireland.

Legends says that Ireland has no snakes because St. Patrick chased them off of the island.  The story is that St. Patrick was involved in the middle of a forty day fast when he was attacked by snakes.  This angered Patrick so greatly that he chased the snakes into the sea and banished them from the island forever.  To this day, Ireland has no native population of snakes.

The truth is that there were never any snakes on Ireland for St. Patrick to chase away.  Ireland has been covered with glaciers during more than one ice age.  During the last glacial maximum, which occurred about 11 thousand years ago, three-quarters of Ireland was buried under a thick layer of ice.  The remainder of the island was too cold and inhospitable to support snakes and most other species of wildlife.

When the glaciers retreated, Ireland was temporarily connected to Great Britain and the rest of Europe by a land bridge.  This connection allowed some species to repopulate Ireland, but snakes did not make it across before the connection was severed by rising sea levels.  This isolation is the true reason for Ireland's lack of snakes, not an angry fifth century saint.

Michigan was affected by the same glacial periods as Ireland.  It also was scoured clean by a thick layer of ice.  However, Michigan remains attached to the rest of North America and snakes have repopulated both the Upper and Lower Peninsulas in the past 11,000 years.  A total of seventeen snake species currently call the state home.  I am glad that they are here.  They play an important role in the ecosystem as both predators and prey.

Upcoming Event - Bluebird Nest Box Build (Saturday 19 March 2016)

This Saturday (19 March 2016) at 9:30AM, members of the Chippewa Valley Audubon Club will be building nest boxes for Eastern Bluebirds (and other small cavity-nesting birds) at the Mt. Pleasant Parks maintenance shop at Nelson Park in Mt. Pleasant.  We will be building the same type of box that I wrote about in my post from February 22nd.  Materials for these nest boxes  cost approximately $16.

I am the leader for this event.  If you live in the Mt. Pleasant area and are interested in building a nest box, please contact me before noon Friday (18 March) to reserve a place.  My email information can be in my profile to the right.

More Woodworking for Bees - A Bumblebee Nesting Box

I am an old hand at creating homes for native bees.  It is easy to make a nesting block that mason bees, leafcutter bees, and small carpenter bees will love.  Other bees are satisfied if you leave a bare patch of soil or hollow stems for them to nest in.  However, there is one group of native bees for whom I have never tried to create a nesting site - bumble bees.

Not any more.

My new bumblebee nesting box - waiting to be placed in its new home

On Sunday (13 MAR 2016), I built my first bumble bee nesting box.  Bumblebees have different nesting requirements than other native bees.  Like the European Honey Bee, most  bumblebee species form colonies with a queen and workers.  Unlike the honey bee, these colonies only last for a single year.

Each fall new queens are born.  They mate and then seek a place to hibernate.  In the spring those that survived winter emerge from hibernation and begin seeking a place to establish a colony.  She often searches out an abandoned rodent burrow or some other underground cavity.  Sometimes she will nest in a cavity in a tree or even simply at the base of a clump of grass.  Once she establishes her nest, she will continue to forage for nectar and pollen until she has enough sterile daughters (workers) to take over foraging.  Late in the summer she will lay eggs that will become fertile queens and drones (males).  After the young queens and drone have left the nest as adults, the colony's work is done and the remaining bees will eventually be killed by cold temperatures.

Many species of bumble bees have recently undergone severe population declines, with one or more species having actually gone extinct.  Part of the reason for this decline may be related to habitat loss as many former nesting sites in fencerows and field margins have been converted to crop production.

My gardens at home always seem to have a healthy population of bumblebees.  I am hoping that by adding a nesting box to the garden I will be able to attract a queen and be able to observe the growth of a colony.

The nesting box that I constructed is made from cedar lumber, left over from other projects.  The sides of the box are made from 1x8 lumber and the bottom and lid are pieces of 1x10 lumber.  The edges of the lid were ripped down to 2 inches from a piece of 1x10.  Overall the dimensions of the box are approximately 15 inches long x 9.25 inches wide x 9 inches tall.  The lid measures 16.75 inches long x 11 inches wide x 2 inches tall.  I used both wood screws and construction adhesive to assemble the box.

Front dimensions of nesting box

Lid dimensions

Outside length and width of the nesting box

The interior of the box is divided into two chambers by a scrap of 2x6.  A piece of 3/4 inch (inside diameter) PVC pipe provides access to the first chamber from the outside.  A 3/4 inch hole drilled into the 2x6 divider provides access to the second chamber.  Ideally, bees will nest in the inner (second) chamber.  This chamber should be lined with some sort of soft nesting material for the bees to begin nesting on (wood chips, cotton, straw, etc.).  I added some paper rodent bedding and will probably add some grass clippings as I do spring cleaning on the garden.  This second chamber also has several ventilation holes drilled near the top.

Inside dimensions of the nesting box

I plan on placing this box on the ground in a corner of the garden formed by an angle of the house.  This site is under the eaves so it is somewhat protected from rain.  The location is also shaded for much of the day with full sun only in the early morning - this is important so the box (and its occupants) do not overheat.

I am going to wait a coupe of weeks before I place this in the garden - there are not really any flowers as of yet.  In the meantime, I plan on taking it in to the office and displaying it with the hope that it will inspire others to think about native bees.

Happy Pi Day!

Happy Pi Day!  What is that you ask?

Pi is a number - expressed to the ten-thousandths place it read as 3.1415.  The circumference of any circle is its diameter times pi.  The are of any circle is its radius squared time pi.  So what does that have to do with today?

Today is the 14th of March.  Otherwise expressed as 3/14 or 3.14.   Just like the number pi. 


To learn more about Pi Day and how to celebrate the event please visit the official website of Pi Day.

A Change in Seasons

An early morning Red-winged Blackbird (11 March 2016)

 
The calendar may say that Spring does not begin for another 9 days, but the Red-winged Blackbirds (Agelaius phoeniceus) beg to differ.  On Saturday (05 March) I began to hear them in the Lansing area.  By Wednesday (09 March) they were everywhere in Mid-Michigan.  To be more exact, male Red-winged Blackbirds are everywhere.  They are busy trying to impress each other and jockeying for territory.  It may take a couple of weeks to sort out which bird ends up with the best places in the landscape.  In the meantime, the females should find their way north to Mid-Michigan.  They will then set about choosing their own territories (within those of a male).  A dominant male bird may have several females living in his territory and will mate with each of them.  The females select a mate based on territory - a male with a good territory will more likely have good genes to pass on to his offspring.  So it doesn't bother them that their mate may have other mates. 

Into the woods - A walk at Mission Creek (Part 2) and the Wildflowers of 2016 (#1)

This is the second half of a lengthy write-up about a walk that I took through Mission Creek Woodland Park yesterday (08 March 2016).  For Part 1, please look here.

With all of the recent snowmelt, Mission Creek is running full and is full of sediment.  It has the color and clarity of chocolate milk.

Mission Creek is full of muddy water

Once I crossed over Mission Creek and into the Cedar-dominated swamp, it was like stepping into an entirely different season.  South of the creek the snow is almost gone, north of the creek the ground is still covered.  This has to do with a couple of factors.  The canopy cover in this section of swamp is much denser than the Red Maple section, blocking more sunlight from hitting the ground and melting the snow.  Also, the creek itself is bounded by a very tall bank, when the sun is at a low angle in the sky (such as during the winter months) it can't reach some sections of the cedar swamp at all.

This short stream originated from a series of hillside seeps

Instead of run-off from melting snow, the northern edge of the park is full of running water from  seeps where groundwater flows out of the ground and drains into Mission Creek.  This constantly running water means that much of the ground here never freezes solid, unlike other locations in the park.

This section of Mission Creek is my favorite place in any of Mt. Pleasant's parks.  It is such a different habitat compared to the other parks.  Cedar swamps are rare in this part of Michigan so this is like a small piece of northern Michigan dropped into the local habitat.

The trail runs through a cedar swamp along the edge of Mission Creek

Many years ago, when I worked for the Mt. Pleasant Parks Department, I hauled a bunch of lumber down along the Mission Creek and built two sections of boardwalk over very wet and eroded areas.  One of the sections was just laid as a tread atop sections of log on the floor of the swamp.  The other section of boardwalk was more substantially built up.  The log section has begun to decay because it was placed right atop wet soil - the higher section is still standing through a grove of cedars.  It's doesn't seem like much, but it has kept this small spot from suffering further erosion due to foot traffic.

A short boardwalk along Mission Creek

Although the trail through the park is fine, I always discover more when I move off the trail.  Even though I have spent dozens (maybe even hundreds) of hours in this park.  I often discover new things.  Yesterday I found an interesting old cedar stump.  The stump itself is not that interesting, the area was logged long ago and there are larger stumps hiding in the woods.  What was really cool about this stump was the pair of trees growing from the top of it.

Sometime in the past, a pair of seeds landed on this stump and germinated.  One of the seeds came from a Northern White Cedar, the other belonged to a Yellow Birch.  Seeds often germinate on top of old rotting stumps, but most do not survive.  Both of these trees have managed to survive.  As the stump decayed, the two trees began to outgrow their home.  They both reached down toward the ground with their roots, seeking additional water and nutrients.  Eventually, the stump will decay completely.  If the trees survive, they will be raised above the ground by their stilt-like roots.

The cedar has another twist to its story.  When it was a young tree, something bent it toward the ground - perhaps heavy snowcover or a fallen branch.  This caused the tree's trunk to curve downward, but the end of the trunk grew upwards.  The result was this S-shaped bend in the trunk

A Northern White Cedar (left) and Yellow Birch (right) growing from an old stump

I also found my first wildflower of the year!  Not surprisingly, Wildflower #1 of 2016 is the Skunk Cabbage (Symplocarpus foetidus).  I half-expected to find this plant.  It is not unusual to find Skunk Cabbage flower poking up through snow.  In 2013, I found my first Skunk Cabbage on almost exactly the same date;  my first 2014 Skunk Cabbage was almost a month later.  I didn't find a lot of Skunk Cabbage yesterday, but I found enough to think that spring is on its way.  Many of these flowers are not yet fully mature.  However a few were open, exposing pollen to insect visitors.

Most of the Skunk Cabbage that I found was growing in flowing water

This Skunk Cabbage flower is beginning to open for business

Skunk Cabbage - Inside the flower on the left you can just see the pollen that shows this flower is open for business.

Although I photographed a few more things before leaving the park, this seems like an appropriate way toe end this post.  Now, I will probably have to wait several more weeks before I find my second wildflower species of the year.  I look forward to it...