Backyard biology art

Minnesotans seem to be proud of their connection to nature.  Recently, I've noticed how many displays of biological art Minnesota folk exhibit in their yards (front and back).  We have watched with great curiosity as the tree stump up the street has changed its shape over the summer.  At first we weren't sure it was biological at all, but now I think it is.



I think it might be a tree carving of a tree -- or perhaps a giant broccoli plant, which it sort of resembles from the back view. The front space is clearly designed to showcase something -- perhaps biological.



Owls are popular yard art, and are well known for their inability to scare away pesky woodpeckers that like to poke holes in wood siding.



The owl below (Olga) lived in my St. Thomas office for 21 years, where it dutifully scared away students who asked too many questions. It was carved from a black cherry stump with a chainsaw by a former colleague in the biology department.

 I have always been intrigued by this metal snail sculpture which resides on a corner across from Snail Lake Park in Shoreview. After running by it for several years, I thought it deserved to be photographed.

One of my favorite pieces of biological art is the giant frog at Tamarack Park in White Bear Lake, made from recycled materials. The long tongue protruding about 8 feet out from his head looks like the old seat of a tractor.  Various car parts, broken bottles, tires, and abandoned pillows make up his body.



Dead trees should of course be left in place to attract the woodpeckers away from your house, but there are some amazing artists that can turn dead trees into beautiful works of nature art.



Click on the image to enlarge it.
http://www.millionface.com/l/awesome-wild-life-sculpture-on-wood-pics/

I can't resist adding more of this great artwork -- probably not from Minnesota.





 

Woodpeckers are eating my house!

I like birds and enjoy watching them flit around in my yard, but the woodpeckers I once tried to attract to my yard with suet feeders, I now want to exterminate. Here's what they have been doing to the house this summer and fall. These holes are in the west wall of the 3-season porch, and there are similar drilled sites in the north wall of the new garage. Both are cedar siding; there are no holes in the harder, older redwood siding. So that's my first clue to what they like -- soft, hollow wood.

The damage isn't just in one spot near the eave; there are myriads of tiny holes they have drilled as "experiments" up and down the wall. Many people must have this problem because there are many links to "how to control woodpecker damage" on the web.

This hole is big enough to be a nest cavity. It might have served that purpose, but I wasn't paying attention back in the early summer. That's some pretty impressive drilling.

Why are they doing this? Theories abound on the web:

• Looking for insects in old, rotten wood (nope, the holes are in the newest wood on the house)


• Drumming to attract mates (maybe early in the summer, but that doesn't explain why they are still doing it now)


• Creating holes to store food (I don't see anything in the holes, but this is something that western Acorn Woodpeckers do)


• Because it's soft wood, that sounds good when you peck at it, and they're bored (my favorite theory because so far I've only observed them pecking at the walls on warm, sunny days).

I tried to take some pictures of the offenders. They don't sit still and their little heads are constantly in motion when they're pecking.

Their head vibrates like a jack hammer against the wood 100 times a minute, which makes me wonder why they don't get a headache. And the deceleration of the head when it actuallly strikes the wood has been measured at 100X the force of gravity. Obviously woodpeckers have some astounding adaptations that permit this lifestyle.

• The force of the bill strike somehow passes underneath the brain through the bill and neck muscles, which are thick and reinforced to absorb the shock.


• Reinforced bone in the skull, especially around the eye sockets.


• Cervical vertebrae with ribs for attachment of these big neck muscles.


• Incredibly long tongues with barbs on the end for spearing prey deep inside those holes they are drilling. The tongue support actually wraps around the back of the skull under the skin, when the tongue is retracted.


• Two toes point forward and two point backward to help brace the bird in a vertical posture on the tree. The stiff feathers in the tail are also used as vertical braces, allowing the bird to lean far away from the tree and accelerate its head rapidly forward to strike with maximum force, like this.

Pretty cool, huh?
Almost cool enough for me to forgive their destructive habits.

Some videos that demonstrate the incredible rate of tat-a-tatting in woodpeckers:
http://www.youtube.com/watch?v=fSGK2MTsTv8 AND
http://www.youtube.com/watch?v=fOG-fgx4QrY&feature=related

Decorative Duck

Nature went overboard in selecting colors for male Wood Ducks. You might expect such a brightly colored species to be tropical, but in fact Wood Ducks are entirely North American, breeding in the Eastern US and southern Canada, and overwintering in the southeastern US and Mexico to Central America.

In contrast to her ornamented male partner, female Wood Ducks are rather plain brown with bright blue under the wing.

Wood Ducks are dabblers, meaning they feed on suspended matter in the water, but they also eat a variety of food on land (e.g., acorns and insects), so they really are omnivores. However, what they were feasting on this particular morning was duckweed. I always wondered if duckweed was actually eaten by ducks or they just swam around in it. But Wood Ducks seem to love it.

This is one of the rare ducks that can perch on limbs (they have sharp nails at the end of their webbed toes) and nests in tree cavities, preferably above water. After incubating their large brood of up to 16 eggs for 30 days, they encourage their hatchlings to launch themselves out of the nest. Of course they can't fly at this stage, which is why a water landing is preferable. I found three females sunning themselves on a tree branch in the early morning before setting out to feed.

There was only a single male on this particular lake, but at least six females (or perhaps the young of the year) accompanying him to feed.

Like the Great Egret, Wood Duck feathers were heavily utilized in the hat industry in the early 1900s, causing a significant dip in the population. Introduction of nest boxes in prime wetland habitat, as well as protection through the Migratory Bird Treaty allowed their population to rebuild.

Even in the shade the coloration of the male is a bold pattern.

Bluebird morning

I went out this morning to look for the Trumpeter Swan family that I saw yesterday (when I didn't have my camera along...). I couldn't find them but I did stumble across a flock of bluebirds cavorting in the weeds next to the "swanless" lake. Bluebirds make good subjects for bird photography because they pause once in a while to look around and see what they want to chase next. Some of their chosen perches were well within the range of my zoom lens in some very photogenic scenery.

How's this for a little fall color matching?

Males still sport the bright blue color on their heads, wings, and tails, which contrasts sharply with the ruddy brown color of the breast feathers. You might not realize that there is no blue color pigment. Instead blue is a "structural color", meaning that it is produced by the feather structure itself. Tiny particles in the feather (smaller than the wavelength of red light) scatter only the shorter light wavelengths in all directions. Thus blue color is reflected from the feather at almost all angles from which it is observed.

Bluebirds like to hunt from a perch, diving into the weeds to chase insects, or hovering above them like a flycatcher. Knotholes on the pines made excellent perches for these hover hunters this morning.

Eastern bluebirds like these seem to be quite common here in the upper Midwest, thanks to the efforts of landowners and park managers who have installed "bluebird boxes" near their ponds and lakes. These artificial nesting holes boosted the bluebird breeding population, which was unable to compete successfully with introduced House Sparrows for natural nest cavities. Typically two "bluebird boxes" are installed about 30-40 feet apart in fields or woods near a source of water. Why two boxes? To insure that there is at least one box for the bluebirds, while the other may be taken by Tree Swallows, Chickadees, House Wrens, or House Sparrows. These species are more likely to tolerate close presence of a different species than one of their own kind.

Not exactly a rose garden

Love of roses is genetic I think.  My mother had a huge rose garden that produced dozens of sweet smelling blooms of assorted colors, and my sisters have beautiful roses in their yards in California as well.  Over the last 25 years a sturdy few hybrid tea roses have survived the Minnesota winters and done quite well in my front yard, but this year, cold June weather stifled growth, intense July heat dehydrated everything, and the the August plague of cursed Japanese beetles munched up whatever flowers were produced, so there weren't enough roses to even fill a bud vase.  Finally after a month long rest from the heat and the beetles, the rose bushes produced a bouquet of large fragrant blooms this week.


Too bad you can't send fragrance over the web...

Heron Cafeteria

I discovered a hot feeding spot for the Great Egret (also known as the Common Egret, but really a heron) while waiting for Alison to start her photo shoot at the Roseville "arboretum" the other day. There were 20 or 30 birds wading in the shallows vigorously attacking whatever swam near them. Fortunately they were amazingly tolerant of walkers on the trail right next to their marsh, so I could stand there without scaring them away.

Wait a minute, who is the ugly duckling is this group of all white herons?

It's the slight larger but close relative, the Great Blue Heron, which also has a white morph in some areas of the world (e.g., Florida). Like the GBH, the Great Egret is found world-wide, and seems to tolerate urban life well because it can be found in lakes and marshes near residential areas.

They are so interesting to watch while they hunt, quickly stretching out their snake-like neck to stab with that long beak at fish, frogs, or whatever else is swimming around down there.

The sun was in just the right position for hunting on this morning, but in mid-day, I've seen them spread their wings like an umbrella around their head and neck to cast a shadow so they can see what is in the water below them better.



When they have exhausted this food supply, they will move on to other lake shallows, building up their fat reserves to leave Minnesota as the temperatures drop and the lakes freeze here.

Interesting note: This species was once hunted almost to extinction back in the 1800s and early 1900s, when fancy bird plumes on ladies hats were stylish.

Another relative seen less frequently in the shallows is the Green Heron. I was lucky to sneak up on this bird this summer and use the highest magnification of my telephoto to get this picture. Green Herons are really secretive and fly away at the slightest disturbance. In fact, they seem to be more nocturnal than diurnal, so this mid-day sighting is a rare one. Perhaps it was foraging for its chicks. Green Herons also have a trick to help them catch fish and frogs -- they drop small sticks or even parts of insects to attract fish to the surface and then grab them with their sharp beak.

That's not grass the bird is standing on. This lake was so shallow and still that the water was completely overgrown with green algae. You wouldn't think that would be a great place for fish to live.

Deer camouflage

Coming back to my car after taking sunset photos the other day, I came around a blind corner and found a beautiful doe standing between me and the car. She was as shocked as I was, but stood there quietly while I took several pictures.

Just minutes before I had been photographing prairie grasses, big blue stem in particular, which reached at least two feet above my head.

Looking at the deer I was struck by how similar their coloration was to those grasses, and wondered whether deer coloration is really camouflage. With a little help from photoshop, here's the result of my experiment: on the left the image of the deer from the top photo layered behind the the prairie grass and, on the right, the image of the deer disappearing into the prairie grass.

Is their natural camouflage in fall vegetation (prime reproductive time) just a coincidence or was their some selection for this coloration during a vulnerable period of their annual cycle? White tailed deer are widespread across the US and well adapted to a variety of habitats, but here in the upper Midwest, they are supposedly forest animals. It seems to me they favor forest edge more than interior forest, and I often see them bounding away through tall thickets toward the woods. In Minnesota the forest edge usually gives way to grassy fields, where the dominant native grasses produce tall, yellow-brown vegetation. Their natural predators, mountain lion (also nicely camouflaged in prairie grass) and wolf, could have hunted both forest and prairie and would have controlled population sizes better in historical times than hunting pressure from humans does today.

Even in mid-winter, deer seem well camouflaged against the tans and browns found in bark of most hardwoods. It could just be the lighting, but they do seem to be a slightly darker brown in winter than in summer and fall.