A long reach...

Deep snow can make winter survival difficult for white-tailed deer.  Getting around is difficult and requires more energy.  Most of the food sources are inaccessible, especially if the snow is combined with a layer of ice that prevents deer from digging down to the ground.

Because foods such as grasses, forbs, and nuts are often unavailable, deer survive mostly on a diet of browse (buds, leaves, branch tips) during the winter months.  Where deer populations are heavy, all the food that is easy to reach is already gone by this time of winter.  Sometimes the only food left available in area is high overhead.  It is not unusual to see where deer have browsed as high as eight feet off the ground by standing on their hind legs.

I retrieved my trail cameras this afternoon and was lucky enough that one of the cameras had recorded this behavior.  The deer in this series of images is reaching up to eat needles from an Eastern Hemlock (Tsuga canadensis).

Normally I just change out the memory cards in my trail cameras and leave the cameras in the woods, but I decided to remove the cameras completely for now.  Even though its in a public park, the area that I place the cameras is quite secluded when the ground is not frozen - it's in the middle of a swamp.  However, right now its easy to access because everything is frozen over.  I also left a trail of footprints directly to the camera sites.  I also recorded a person on one of the cameras.  This is not the first time I have ever seen a person on one of the cameras, but it was the first time I could tell that they knew the camera was there.  Fortunately, they only smiled at the camera and left it in place.

If this you - Thank you for being an honest person!

Frost damage on Skunk Cabbage plants

 This picture shows how Skunk Cabbage (Symplocarpus foetidus) plants should look right now.
 

 

The next picture shows how they actually looked yesterday morning.

Several nights of heavy frost have badly damaged the leaves of the plants.  Hopefully they can recover.
 

It amazing to me that the plant's flowers can melt snow due to the metabolic heat that they generate,

but the leaves can be damaged by a few hours of freezing temperatures.

Ice on the Chippewa River

The recent cold snap means that our local bodies of water are beginning to freeze over, including the Chippewa River.  Yesterday I stopped at Mill Pond Park to see the extent of the freezing.  I found the river partially frozen over with a jumble of icy blocks and ropes.

The deeper main channel of the Chippewa River covered with "pancake" ice

The surface of the river was beginning to freeze from the edges in toward the middle - this known as border ice.  Meanwhile the current continuously pushed blocks of ice and slush downstream.  The slush is technically known as frazil - it forms as semisolid ice in areas of the river where the current is too strong for the river to freeze solid. These blocks of frazil are usually referred to as pans. Some of the pans collided with and held fast to the border ice (and to each other) until the entire surface of the river was covered by ice.

A rope made of ice

One of the coolest features that I saw in the river was a rope of ice that formed along the edge of the accumulated ice pans.  This feature formed as new pans collided with the edge and pushed part of the frazil atop the solid ice.  Standing alongside the river, I could here the grating as these pans slid along the edge.

This rope of ice crystals marks the boundary between the immobile pans of ice and the freeflowing river

A semi-solid accretion of ice pans on the left with unattached ice floating by on the right

Parts of the river were completely frozen across from edge to edge.  Pans of ice continuously flowed against the edge of this solid surface.  Most of the pans stuck tight to the upstream edge, but others were pushed beneath the surface.  If these pans flowing under the surface freeze tight to the bottom of the surface ice they may form what is known as a hanging dam.  The formation of a hanging dam would potentially cause the current to back up and overflow the banks of the river.

Pans of frazil ice flow downstream until they encounter surface ice.

With temperatures for Mt. Pleasant forecast to remain below freezing for at least the next week, the river surface is likely to completely freeze over in all but areas with the fastest current.  The semi-solid pans of frazil that have accumulated on the surface will freeze solid and more ice will accumulate on their undersides.  If temperatures remain cold enough, anchor ice may form on the riverbed in the fasted flowing areas.  Areas with a slow current may even freeze completely solid.

A jumble of border ice, pans, frazil, and open water.

Next time you stop to look at a frozen river, examine it closely and you too might notice all of the unique features that went into crating that icy surface.

Wind Chill - What is it and why is it important?

 
Over the weekend, temperatures in Mid-Michigan dropped to a low of approximately -14 degrees Fahrenheit, but windchill temperatures were much lower dropping down to -31 degrees.

What is windchill?

Windchill is a measure of what air temperature feels like.  This measure is based on the principle of convection.  A solid surface loses heat in three ways: radiation, conduction, and convection.  The human body loses heat primarily through conduction and convection.

Conduction
Conduction is the direct transfer of heat from one object to another.  When you touch an object that is colder than your body, some of your body's heat transfers to that object in an attempt to equalize the temperature of your body with that of the object you are touching.  This is why when you hold an ice cube, the ice melts and your hand gets cold.  Conduction also takes place between you and the air - your body warms up the molecules in the air that contact your body and your body cools slightly. 

Convection
What happens if the air around your body is not still?  If the air is moving, it pushes the warm air away from the surface of your body and constantly replaces it with new air.  The process of conduction is repeated with this new air - this transfer of heat to moving air is known as convection.  Because the air is moving and your body is trying to equalize temperatures, heat is lost at a higher rate than it would be to still air.  This means that the air feels colder than it actually is - this difference in feel is measured as windchill.

Windchill is calculated using one of several formulas.  This data has been collected in tables such as the one below from the National Weather Service. 

Why is windchill important?

If skin is exposed to temperatures that are too cold, it will begin to freeze.  This condition is known as frostbite.  Because convection causes the skin to lose heat much more rapidly than it would in still air, low windchill temperatures indicate a greater danger of frostbite.  The chart above shows the time it takes for frostbite to set in at various windchill temperatures.

Many schools do not allow students outside for recess if windchill (or actual) temperatures drop below a certain level.  Some schools may even cancel school when temperatures drop below a certain threshold.  If yesterday (15 FEB 2015) had been a school day, most of the schools in the area would have probably cancelled classes due to the windchill.

Enjoying it while it last...

Winter fields in Mid-Michigan

Winter is my favorite season, but there are days that make me want to reconsider.

Mt. Pleasant's noontime temperature today measured at 6 degrees Fahrenheit, with windchill at -8 degrees.  Colder temperatures are forecast for the weekend.  Countdown to Spring: 36 days...

In Silhouette

Yesterday morning the temperature was hovering just above zero degrees Fahrenheit.  Many of the trees and other plants were covered with a coating of frost.  I took several photos in the field behind the office.  This one of a dried Queen Anne's Lace (Daucus carota) flowerhead silhouetted against pastel colors of the morning sky was my favorite of the bunch.

Standing in the middle of the river...

I have been looking back at my photos from past years to find something interesting to share and I came across a set of images from 02 February 2009.  I remember taking these photographs because of the unique circumstances.  A few days earlier, on January 27th, I had visited the Chippewa Watershed Conservancy's Sylvan Solace preserve. 

I remember the temperature on January 27th was very cold for Mid-Michigan.  Looking at weather records for that date show a low temperature of about -5 degrees Fahrenheit at 9:00AM.  I snow-shoed from the parking area along the River Loop.  Even with the cold air temperatures, the river was flowing freely with only a little ice along the edges.  Because the river was warmer than the air temperature, vapor was rising up and condensing in the air over the river.  Some of it was forming hoarfrost on trees along the river.  A mostly sunny sky made for some nice pictures.

I took several pictures and an idea formed in my head.

Brrrrr!!!!

Check out this morning's outdoor temperature in the lower left of this picture. 

Inclement Weather

Today was supposed to be the first day back from Winter/Christmas Break  for most schools in Mid-Michigan, but Mother Nature had other ideas.  ALL of the schools in Mid-Michigan are closed due to the winter storm that dropped snow across the state yesterday and today.  Tomorrow's wind chills are supposed to drop to -25 degrees Fahrenheit or colder.  There is a good chance that many schools will also cancel classes for tomorrow because of the cold and poor road conditions.  I went out this morning and shoveled snow from our driveway and sidewalks and by the time I was done I had icicles up to 1/2 inch long hanging from my mustache and beard. If you choose to go outside be sure to dress appropriately.  Take a cue from nature:  dress in layers, fuel up, don't overheat, do what you need to to stay warm.

To learn how small birds such as Chickadees keep warm in cold weather check out this post from last January.

Fox Squirrels fueling up at our bird feeders