Friday, January 30, 2015

Some Color - By Request

I received a complaint that my posts have been featuring too much brown and gray.  Well, that tends to happen during the winter.  Fortunately, winter is a prime time for a wonderful atmospheric event that quickly turns a dreary day into a colorful diorama.

Most people are familiar with the fact that sunlight is made up of a broad pallet of colors, as demonstrated by passing light through a prism to reveal individual bands of color from red to violet.  As sunlight comes streaming through the atmosphere, it collides with air molecules and certain colors are deflected from the light stream.  This process is known as scattering and the scattered colors become visible.  Colors at the violet/blue end of the spectrum are most easily deflected and are broken out for us to see.  That’s what produces the blue sky.  Evening sunlight cuts diagonally through the atmosphere, so the light must travel a longer path.  By the time it reaches us, the violet and blue have already been removed from the beam to create a blue sky somewhere out west and we see the remaining colors from the red end of the spectrum. 

The scattering effect occurs each evening, but to get the best display, you need a platform upon which the show can be displayed.  That role is assigned to clouds that pick up the red and orange colors and present them for us to see.

Best condition for viewing occurs when clouds cover the sky, but don’t reach the western horizon.  The low angle of the sun allows the light to pass through the greatest distance of air and then hit the under sides of the clouds.

The back side of a storm front usually produces the best display, because there is usually a sharp delineation between the moisture laden clouds and the dry air pushing them along.

Naked winter trees backlit by the evening sky put the colorful display to best use.

Whether you get orange, red or pink is a function of the distance the light has actually traveled and the amount of scattering that occurred during the journey.

Blue Jay Barrens has been in the path of a series of clippers moving through out of Canada.  Several have passed through just at dusk and have left wonderful conditions for beautifully colored skies.

The timing isn’t always perfect.  Most of the storms have been in a hurry and sometimes drift away without putting on a show.  These sunsets have no bearing on the biological functions at Blue Jay Barrens, but they do a wonderful job of entertaining me. 

Wednesday, January 28, 2015

Feeder Birds

Two quick moving storms over the weekend brought a total of three inches of snow to Blue Jay Barrens.  Snow typically increases the number of birds visiting the feeders, so I paid particular attention to that area in hopes of seeing some new additions to the normal mob.

In order to reduce the number of deer visiting the area, I usually wait until the sun is well up before replenishing the food and water supply.  Blue Jays begin arriving at daybreak and line up in the surrounding trees to await my appearance.  If I’m delayed for any reason, they begin to get noisy.  The Jays are first to the feed and pretty much dominate the scene for the first 15 minutes. 

Blue Jays primarily utilize a grab and go technique.  Their time on the ground lasts only seconds as they take a sunflower seed or bit of corn and depart.

Most take their find directly into the apple tree beside the feeder.  Here they shell their sunflower seed or wedge their corn into a crevice where it can be broken into smaller bits.

The apple tree has a definite wild and unkept look about it.  The branches are too interwoven and closely spaced for good fruit production, but they form a tangle that makes the birds feel safe.

Mourning Doves move in once the Blue Jays have finished. 

The whole schedule can be put on hold when the Wild Turkeys show up.  Fortunately, the turkeys normally visit the feeder in late morning, so most other birds have already had a chance at the feed.

While the larger birds feed in the open, smaller species forage in a forest of dead Giant Ragweed stalks.  Although the stalks seem brittle and fragile, they have not bowed to the pressures of wind or snow. 

The birds cleaned up the ragweed seeds long ago, but I always scatter some fresh feed among the stalks.

The House Finches seem to prefer feeding among the stalks.  They will visit the feeder mounted next to the ragweed, but they tend to shy away from feeding in the open area beneath the apple tree.

 There seems to be a constant stream of birds moving between the feeder and the ragweeds.

I was expecting an increase in bird numbers because of the snow, but the arrival of a single Evening Grosbeak was the only thing that made the snow day different from any other we’ve had during the past month.

Throughout the day, the regular birds arrived at their normal times.  I guess the snow just wasn’t enough to change any normal feeding patterns.

The woodpecker tree, despite the fact that it’s now on its side on the ground, continues to attract woodpeckers.  This Hairy Woodpecker consumes sunflower seeds from the feeder, but it also spends considerable time digging for insects in the dead wood.

The arrival of the Cooper’s Hawk signals an end to the feeding activity.  If I look out the window and see no birds, it usually means that the hawk is somewhere near.  This time he was sitting atop a branch stub projecting from the downed woodpecker tree.  This is a common perch used after an unsuccessful raid.  I’m sure he would have appreciated a large congregation of birds brought in by a heavy snow.  Maybe that’s not going to happen this year.

Monday, January 26, 2015

Fishing Spider

I use this flat rock to monitor the progress of breeding Streamside Salamanders.  This section of the upper reaches of the creek typically has a moderate flow of clean water through the winter and spring seasons.  The salamanders visit here in good numbers and have used the underside of this rock for the past several years as a repository for their eggs.  The rock is not embedded in the stream gravel and is easy to lift for a peek beneath.  No salamanders were found during my last check beneath the rock.  Instead, as I tipped the rock up on its side, a large spider fell from beneath and began floating away in the current.

I quickly scooped the creature out of the water and found it to be a female Fishing Spider, Dolomedes vittatus.  This species is found near small, running streams and is covered by water repellent hairs that allow them to walk on the water’s surface.  They can also submerge, with the hairs maintaining a surface film of air around their bodies.  I couldn’t tell if this individual had actually been utilizing an air pocket beneath the rock or if it was just utilizing the film of air covering its body.  The bottom of the rock is smooth and fully submerged, so if an air pocket was present, it would have to be small.  Using the warmth of the water is a neat way to survive subfreezing temperatures.  Even at its coldest, the temperature of flowing water in the creek doesn’t drop below 32 degrees F.  When nighttime temperatures hover near zero, taking advantage of the warmer water temperature is a distinct advantage.  The surface of the air film covering the spider would also allow for oxygen and carbon dioxide exchange with the flowing water.

The spider was cold and its first movements caused it to roll down into my hand.  As the spider gained warmth from my hand, its movements became more coordinated.  It wasn’t long before it wouldn’t hold still for more photos.  I released it into a cavity beneath a large rock that set half in and half out of the water.  I figured the spider could choose whether or not to return to a submerged resting spot.

Talking about spider size can sometimes be confusing.  This is considered to be a large spider for this area.  If I described it by using the common measure of body length, I would say that it was just a little over half an inch in size.  That might seem small to many people.  If I used the length from the tip of one leg, on through the body and out to the tip of the opposite leg, this spider would be described as 3½ inches across.  Some might use those dimensions to describe it as palm sized.  Either way, it makes it sound like one big spider, but most of that size is just open space between the legs.

This is an attractive species.  The two dark markings near the center of the carapace and the rows of white spots along the abdomen are diagnostic.  Notice that this individual is missing one of its hind legs. 

Good eyesight is a must for these hunting spiders.  A row of four small eyes sits below a row of four larger, more widely spaced eyes.  This lady shouldn’t have any trouble keeping track of her prey.

From the front, the markings of the spider seem to form a face.  The abdomen is decorated with two dark spots with white edging that look like eyes.  The twin dark markings on the carapace suggest a nose and the curved rows of eyes designate the mouth.  I don’t know that this configuration of characters actually serves any defensive functions, but it’s still interesting.  The shape and markings of the abdomen as seen from this angle remind me of the 1978 version IL series Cylon.  By your command.

Friday, January 23, 2015


This is the fallen fruit of the Osage-orange, a tree commonly found in old fence rows.  When I see this fruit, I always think of Mammoths and Ground Sloths, two members of the megafauna that used to roam this area until their extinction nearly 10,000 years ago.  These large herbivores were the last species to utilize the fruit as a food source and were the primary dispersal mechanism for the seeds.

Osage-orange produces an abundance of seed inside the fleshy fruits.  The large herbivores would eat these fruits whole and pass most of the seeds undamaged through their digestive systems.  The animals would then wander around dropping the seeds with their dung.  In this way, the trees were spread across the landscape.

A few modern mammals are attracted by Osage-orange fruits, but it’s not really the fruit they are after.  Most of these animals, such as squirrels, are seed predators that actually open and eat the seeds.  Empty seed coats are all that remain of seeds that will have no chance of being dispersed.

The actual flesh of the fruit is left behind to decompose.

At the time of European colonization, Osage-orange was only found in the Red River Watershed region of eastern Texas.  The trees found here today were introduced and are not considered native to this area.  Since the tree was spread so easily by large prehistoric herbivores, I wonder if Osage-orange might have had a much broader range during the Pleistocene when the megafauna were so common and widespread.  I haven’t read anything that suggests such an idea, but I think it’s a possibility.  Osage-orange may have actually grown on this spot in the far distant past.

Osage-orange was commonly planted as a living fence.  Its tight growth, along with the presence of some strong thorns, helped to keep livestock contained within the field.

Their habit of spreading limbs far out into the field, caused Osage-orange to be removed by many farmers who didn’t want to be raked from their tractor seat by the thorny branches.  There are only a few of these trees growing at Blue Jay Barrens.  Most show signs of having been cut at some time in the past, most likely for use as fence posts.  Despite the fact that the seeds are viable and easily germinated, the trees are not spreading into the fields, so they don’t currently fall into the invasive category.  For now, I’ll leave the trees alone and keep imagining that a herd of Mammoths has gathered around the tree to eat fruit.

Wednesday, January 21, 2015

Cedar Maintenance in the Middle Field

The marking flags are once again flying in the field as I resume my cedar maintenance activities. 

I’m working in what I think of as the Middle Field.  The field seen through the trees is the Far Field, which runs up against the County road.  In the other direction is the Near Field, which sits beside the house.  Between those two fields is the Middle Field.  It makes sense as long as you don’t consider all of the fields that are in other directions from the house.

The Middle Field is a narrow, wedge shaped field that points to the north.  Even though it is only two acres in size, the Middle Field contains a variety of diverse habitats.  Along the east side is a shallow valley containing a small, intermittent stream.  A narrow strip of deep soil along the stream bank encourages tree growth.

Just a short climb up the slope brings you onto shallower soil where the prairie vegetation dominates.

The areas of open grassland reach as narrow fingers among the tall cedars.  In these areas I don’t need the help of flags to guide my search for little cedars

At the top of the slope is a small thicket of Virginia Pine.  It’s not hard to pick out the tree that was most likely the original colonist.  The rest of the stand probably originated from that single individual.

Just through the pines, the field opens up onto a level hill top.  As the old fence row is cleared, this part of the field will become more associated with the Near Field seen through the trees to the left.

A thriving stand of Dwarf Sumac is found on the hill top.  We’ve had nearly no snow so far this winter, so the Sumac fruits have not been touched by the birds.  The sumac fruits seem to be eaten only out of necessity.  It’s only during the harshest of winters that this fruit seems to disappear.

The pointy end of the Middle Field has already been mowed.  If weather permits, I’ll mow the rest of the field following the cedar maintenance activities.

I’ll be removing Eastern Red Cedar as well as Virginia Pine seedlings from this field. 

Virginia Pines produce an abundance of seeds.  Those seeds seem ready to germinate as soon as they hit the ground, so pine seedlings are especially abundant near the mature pines.  Fortunately, if cut off at ground level, the pines will not regrow.

Because the field was mowed just three years ago, the young cedars are not very tall.  I generally like to conduct cedar maintenance activities in a field prior to mowing.  Sometimes circumstances conspire to limit the amount of time available for field work and I must decide which would be the most beneficial activity to pursue.  Three years ago, I decided to limit the threat of cedar competition on the prairie plants by going ahead and mowing the field.

As a result of that earlier decision, I am now cutting cedars that have regrown from a cut stem.  These individuals form a dense top growth, but still have only a single stem needing cut.

The mower actually caused the stem of this cedar to split three years ago.  Live branches, safe beneath the cut, responded to the loss of the tree top by generating some rapid growth.  The loss of a dominant top stem allowed the side shoots to grow uncontrolled in an attempt to replace that dominant leader.  As long as there is the least bit of green growth left, a cut cedar will successfully regrow.

My activities don’t go unnoticed by the local residents hiding behind an old brush pile.  They usually don’t seem too interested in my cedar maintenance activities.  It’s the mowing that they really get excited about.  They can’t resist checking out the interesting odors generated by freshly cut vegetation.