The Eastern Fox Squirrel who evicted the Nuthatches

Don't mess with my nest!

Years ago, I bought a nesting box made specifically for larger woodpeckers.  I was told to pack it tightly with cedar chips, which I did.  I watched and waited as it hung on my tree.  Time went by that spring, and no signs of any interested parties.  I gave up.  Mid-summer, I was out mowing the lawn and just happened to glance over at the box.  I didn't see a woodpecker, but did have the opportunity to watch a pair of White-breasted Nuthatches involved in some type of courtship ritual.  Weeks later I watched as their babies fledged.

White-breasted Nuthatch (Photo:Wikipedia)

That was the only year the bird box was actually inhabited by any type of bird.  In no time, word got out to our local Eastern Fox Squirrel (Sciruis Niger) population that there was a vacancy. 

Fox Squirrels will make two homes per year, called "dreys", depending on the season.  In the summer they snip branches and weave them way up high in the tree canopy, safe from ground predators and bed them with dried leaves.  In the winter, and when raising their young, they will occupy a cavity.  Single cavities have been found to be used for up to 30 years!   By the looks of it, this nest box will be home to a family of squirrels again this year, and many more.  Mama is guarding her home with ferocity.  I watch as small songbirds try to investigate, she is always on guard and quick to scold anyone who might get too close.

Love, hate or tolerate.  What is your feeling toward squirrels?  I've always viewed them as a comical resident in my yard.  They provide hours of entertainment, or frustration, for our dog.  He will stand on point for very long periods of time, locked eye to eye, just waiting for the opportunity that will probably never come.

I see a frog! Where was it all winter?

I have noticed a lot of activity outside over the last few days.  The Sandhill Cranes, Canada Geese and Mute Swans have all returned to our neighborhood.  Songbirds seem to be more abundant and flying around with purpose.  I even found a couple of frogs hopping among the grass, dirt and snow.  The question in my mind is this.  How do animals know that spring is coming?  Do they have a complex network of secret communication?  I know for a fact that they do not have a calendar like I do.  So, there must be something that is signaling them.

Animals pick up on what are called "environmental cues".  Warmer temperatures and an increase in the length of daylight are the two main cues that get animals moving and active as spring approaches.  Birds for example respond to the change in the length of daylight, also called photoperiod.  Along with warmer weather, photoperiod promotes changes in the color of fur and feathers, migration, reproductive behavior and exit from hibernation.

My mind turns specifically to the frogs that I saw this weekend.  Where were they all winter and why am I seeing them now?  I know they are cold-blooded, so their body temperature is directly effected by the temperature around them. This past winter was so brutally cold, why didn't they freeze to death? 

                                             (Photo credit: Naturenorth.com)

OK, here is where the biology geek in me takes over.  There must be a logical explanation for this.  Let me explain to you what I refer to as "the frogsicle".

In the fall, frogs and toads will burrow into the bottoms of ponds or lakes or in mud.  Since they are cold-blooded and take on the temperature around them, they actually go through freeze and thaw cycles.  Do they have antifreeze in their blood?  No, but their blood does contain what are called nucleating proteins, which act by causing the water inside of the frog's blood to freeze first.  This action causes the remaining parts of the frog to dehydrate.  At the same time, their liver starts producing large amounts of sugar in the form of glucose.  This glucose packs itself into the cells of the frog, which keeps its body and organs in their current shape and form and puts the frog into a state of suspended animation.  No brain activity and no heart beat....their bodies filled with a sugary syrup, their internal organs and structures protected, they are able to make it through the subzero temperatures that they endure all winter.

As spring gets close, sunlight increases, temperatures warm and things around us begin to thaw, so does the frog.  The water is restored to the cells, their brain function turns back on and their heart begins to beat once again.

So, as you begin your spring thaw, and you begin moving around outdoors a bit more.  Maybe cleaning out your garage, cleaning up after your pet's winter happenings, talking to neighbors who have also been locked inside for the last several months, take a little walk.  Maybe visit a nearby park.  Michigan has a lot of parks with trails just waiting for you to hike.  See if you can notice things around you that are changing.  Keep your eyes out for frogs.  I hope the next time you see one, you will have a little more understanding and appreciation for the fact that they made it through the winter.

Check out this cool video from Nova which shows a frog freeze and thaw!

A Hootin' Good Time! (Eastern Screech Owl Style)

Spring is a very active time for all types of exciting events that happen outside.  All you have to do is take the time to spend a short amount of time in the woods, in a field, by a stream or in your yard to get a glimpse at all the changes that are occurring.

As Spring begins to show itself in SE Michigan, I found myself visiting the roosting area of an Eastern Screech Owl who had been hanging out across the street from my house all winter.

 

He or she is no longer at that perch, I am assuming that it is protecting a nearby nest.  The courtship with another of its species most likely took place during night hours, while I was warm and sleeping in my bed. 

All winter I imagined how many pellets must be piling up at the bottom of that roosting tree.  Well, today I ventured over and did some collecting.  The pellets were pretty damp, so they are currently drying in my laundry room on some newspaper.  My husband will not think this is weird.  After all, he knowingly married  a self proclaimed "bird nerd" and biology geek.

For those of you who may not know, owl pellets look like they might be "poop", but they are not.  Think of a hairball from a cat.  Well, a pellet is very similar, but contains the fur and bones from the bird's prey.  Sometimes one pellet might contain an entire skeleton.  What do Screech Owls eat?  Insects, reptiles, small mammals such as bats, mice and other small birds.

A little bit about the Eastern Screech Owl (Megascops asio).  When you think of an owl, you probably picture a large bird like the Great Horned Owl or Barred Owl that you see in movies or in photos.  Screech Owls are much smaller than this.  They are only about 7-10 inches tall, which is about half the size an American Crow (16-21 inches tall).  Screech Owls are primarily solitary, mate in late-winter, are monogamous and both adults care of the nest and young.  The male will build a nest in a tree cavity, maybe abandoned by another animal or bird, and the quality of that nest will be the determining factor in whether or not he will find a female to mate with.

To learn a lot more about the Eastern Screech Owl, I highly recommend you visit Cornell's website on Ornithology HERE.