Thursday, March 24, 2011

Robin-Early Bird Gets Worm

 In the middle of yesterday's snowstorm this Robin was wondering what happened to the nice spring weather.  At least that is what I imagined he was thinking.

The Robins seem to have arrived en mass a little early this year, but last week almost all the early migrators arrived within a few days.  Red Winged Blackbirds, Sand Hill Cranes, Great Blue Herons, Grackles, Fox Sparrows, Wood Cocks, are just a few of the ones I saw.

But this snow and cold weather will test some survival skills.
I don't normally consider birds able to make expressions with their fixed beaks, but this Robin seemed to be telling me what he thought of this weather in this picture.

The first and strongest migrants that arrive get first pick of the best territories, so this Robin is willing to put up with some cold weather for a choice space. 
Even though the Robins are here, I was very surprised to see this earth worm lying in the snow, slowly moving, in the middle of the trail at Springbrook on Tuesday.  While it doesn't look injured, I can only imagine that some bird, probably a Robin, dropped it while flying to a perch.  Who knows? 

But this is a case where I think the early bird-in this case the early migrating Robins, really did get the worm!  Or at least tried and dropped it later.

Sunday, March 20, 2011

Pileated Woodpeckers Create Tree Mulch

 Pileated Woodpeckers are the largest woodpeckers in Minnesota--really in North America, unless the Ivory Bill still actually exists.  Pileateds are the size of a crow and are impressive and beautiful birds.  They are not uncommon, but they are shy and keep from sight as much as possible.  This male is one of the pair that live at Springbrook.  I was able to take these pictures a couple of days ago at the bird feeder area at the nature center. The female kept out of sight behind the tree.  The male is identified by the red extending back from the beak.  In the female this line is black.
 In this picture you can see how woodpeckers use their stiff tail feathers as a prop to hold their body away from the tree while looking for food.
The red crest is very bold on these birds, and is raised or lowered depending on the birds level of excitement.

As you can see in the pictures below this pair of woodpeckers have ravaged a number of trees during the winter while looking for the insect larvae inside that provide them with enough nourishment to survive snowy and cold winters.
 This tree was shredded inside and out looking for the grubs that were living inside.  This is a common sign that Pileated woodpeckers live in an area.  I took both of these pictures in the last few days at Springbrook on the trails.  From the trails you can see the evidence left by the Pileateds all along the wooded areas.  Piles of fresh wood mulch on the ground at the base of a tree is proof that these woodpeckers are visitors to the area.
This cavity was over four feet long with the obvious huge pile of wood chips on the ground in front of it.  Another cavity just as long was immediately above this one, but had been done at least a year ago.

If I could just get these woodpeckers to make mulch for my gardens like this!  But I hope the trees in my yard don't have this many insects living inside.

Sunday, March 6, 2011

Hawk and Owl Eye Protection-Nictitating Membranes

 All birds have a second eyelid that cleans and protects their eyes. It is called the nictitating membrane.  Hawks and owls have large eyes that protrude and need constant cleaning.

In these pictures you can see how the clear cornea is right out there in front.  Any debris or dust blowing by will stick to this moist surface. 
 This is the Red Tailed Hawk that has been hunting in Springbrook's bird feeding area most of the winter.  It sits in the tree right outside the windows, and I took these pictures through the windows in the last few days. 

This picture shows the nictitating membrane that sweeps the eye from the side in just a milisecond.  You can see how this membrane is not quite clear, and is a bit more opaque in the Barred owl below.
I took this picture also in the birdfeeding area at Springbrook.  These birds watch constantly for prey and need the best vision possible.  The nictitating membrane helps make that possible.

The Barred owl's eyes are large and almost a deep black when the membrane is pulled back.