Wednesday, August 20, 2014

Goldfinch Nest

I was wandering through the field, tracking down the last of the Teasel, when a female Goldfinch suddenly shot out of this small Flowering Dogwood.  I’m used to Goldfinches chattering away as they move around in small flocks from one feeding site to another.  A lone bird hiding in a tree must mean there’s something special about that tree.


I moved closer and could detect a brown mass concealed by the leaves.  A nest.  Small shrubs and trees in a generally open field are heavily utilized as nest sites by many bird species.  The nests are difficult to see while the leaves are on.  In early winter, when the leaves have all dropped, the nests are quite conspicuous.


Goldfinches typically lay between four and six eggs, so this nest could still receive another egg or two. 


The nests are commonly lined with pappus collected from thistle seed heads.  Pappus is the fluffy material attached to the thistle seed that allows the seed to be lifted by the wind and carried to distant locations.  The tall thistle species are just beginning to bloom at Blue Jay Barrens, so they are not yet a source of pappus.  I believe this nest lining came from the shorter and earlier blooming Pasture Thistle, Cirsium pumilum.


There’s not much chance of this nest being dislodged from the tree. The sides of the nest are strongly anchored to a half dozen stout branches.


Spider webs are used on the cup edge and the outside of the nest to help hold the material in place.


While admiring the Goldfinch nest, I noticed a similar brown mass in a nearby Redbud.


I believe this to be the nest of an Indigo Bunting.  I’ve seen active bunting nests and this matches what I’ve seen before.


I periodically remove the trees and shrubs growing in this field when they begin to overtop the prairie grass.  When they are small, the trees serve a valuable function as nesting structures.  Fortunately, there are always new volunteers coming along to take the place of those specimens I remove. 

Monday, August 18, 2014

Black Rat Snakes

I noticed some mouse activity around the stored bird seed in the garage, so I knew that the Black Rat Snakes had moved out of the house.  Like many predatory species, the Black Rat Snake breaks its home range into hunting parcels.  It will hunt in one parcel until the prey becomes scarce and then it will move into the next parcel.  By the time it has made the circuit through all of the parcels, the prey will have rebounded in the first parcel and hunting will again be good.  My garage and attic make up one parcel.


Black Rat Snakes become more uniformly dark as they age.  In good light though, you can still see a remnant of the handsome pattern worn by the snake as a youngster.


Snakes moving across a loose substrate cannot get the leverage they need for smooth gliding locomotion.  They must use their muscles in a different way to achieve something similar to a belly crawl.  This is their equivalent of a person crossing an icy parking lot.  I’ve heard people attribute this condition to snake arthritis, road accident, dog attack, vicious clubbing and many other imaginative afflictions, but it is really just a natural condition for the snake under certain circumstances.


I found this snake coming around the corner of my barn and noticed that it was in a perfect position for estimating its length.  This wall was built with standard concrete blocks which are 16 inches in length, including the space between blocks, when in place.  The front part of the snake stretches two and a half blocks or 40 inches.


Around the corner we find the tail end stretching about four fifths of a block or 13 inches.  Add on another inch to cover the portion that wraps around the corner and the snake totals 54 inches or four and a half feet.  An impressive specimen.


The snake proceeded along the wall and entered the barn by way of the small space beneath the large barn door.  As soon as it got inside, it began scaling the wall.  These snakes are excellent climbers and easily ascend what is practically a smooth vertical surface.


The shelf atop the barn wall is a preferred site for shedding old skin.  This is usually my first indication that the snakes have moved into the hunting parcel that includes the barn.


Here are three fresh sheds, all left within the past week.


I usually take the skins and hang them in a nearby tree.  With luck, there will still be some lengths of skin around next spring that are suitable to those birds that use this type of material in their nests.


While I was exiting the small barn door, this young snake was trying to enter.  Its juvenile pattern is clear to see.


The small snake showed signs of having recently fed.  I hope that bulge represents a small mammal and not one of the adult fence lizards.


The water tubs at the barn corners are frequently used by the snakes. 


I usually see the snakes scale the barn wall to access the water tub.  This one chose to employ the stepstool method.


Large quantities of water are often consumed at one time.  This one drank for almost a full minute.


The snakes sometimes soak in the tub and I thought this one was going to do just that.


Instead of soaking, it shot through the tub and out the other side so fast all I could catch was the tip of its tail disappearing over the back side.


It took off across the grass and entered the field beside the barn.  It’s fun to watch these snakes going about their business undisturbed. 

Friday, August 15, 2014

Teasel Topping Time

There are a sufficient number of invasive plant species at Blue Jay Barrens to allow me to perform control work at any time of the year.  Each species has a season in which it is most susceptible to some type of control strategy.  August is the time for Teasel control.  Teasel is a tall, spiny plant topped by a head of purple flowers.  The flowers fall away leaving a bristly cone full of seed.  The most effective means I have of eliminating this plant is to harvest the seed heads before they can release the mature seed.


A split seed head reveals rows of nearly mature seed.  At this stage of development, the seed is held tightly in place.  In another week of two, the seed head will dry and the seed will be free to fall.  Movement of the plant stalk by wind or animal will cause the seed to scatter over the surrounding area.


Teasel is a biennial plant that dies after producing seed.  By removing the seed heads prior to seed dispersal, the species is denied future generations.  The local population is reduced to scattered plants after just a few years of seed collection.  It can still take several more years before viable seed left in the soil has all germinated.  Missing a single year of seed collection could result in the release of fresh seed and a resurgence of Teasel in the field.


The tall prairie grasses are just beginning to send up flower stalks, so the Teasel is about the tallest plant in the field and fairly easy to see.  I drop the seed heads into a bucket as they are gathered and then empty the bucket into a feed sack such as that seen in the center of the photo.  I also use the feed sack as a reference point that allows me to coordinate my search so no part of the field is missed.  When doing work like this it is important to stay oriented so you can conduct a thorough search.  Just wandering around will result in missed plants and unsatisfactory results.


Occasionally, clusters of plants are found.  This usually means that there was some type of ground disturbance that allowed multiple seedlings to prosper.


An abandoned ant hill was responsible in this case.  The loose bare soil was perfect for invasive plants.


In some of these places, the first year rosettes are growing at the base of the dying Teasel stalks.  Those rosettes will be flowering plants next year.  The rosettes can be easily killed by spraying a little bit of glyphosate on the growing point in the center of the plant, but I won’t use that treatment here.  There’s no way I can locate all of those rosettes hidden in the surrounding vegetation, so it’s more effective for me to just wait until next year and rob these plants of their seed.


The majority of seed heads are nearing maturity and the plants are dying.  On a few plants, the flower is in bloom or even just beginning to bud.  I pick anything that could possibly produce seed.  Any actively growing plants are not likely to be successful in producing new blooms and developing seeds before being stopped by frost or freeze.


When seed head collection is completed, I destroy the seed, so there’s no chance of it growing here or anywhere else.


As always, I watch out for anything making a meal of invasives.  I found this pink looper caterpillar munching on the Teasel seed capsules.  I only found a single caterpillar, so I don’t think this is a threat to the species.


Even though they are invasive, the Teasel flowers attract a wide variety of butterflies and other pollinators.  This Southern Cloudywing was looking quite bright and crisp.  I would guess that it just recently emerged.


I try not to let too many things get me off task, but I can’t walk by without cutting any little cedars I find growing in the field.


Walking the fields for invasive control also gives me an opportunity to notice any changes in species composition.  I found several new Spider Milkweeds, Asclepias viridis, that had migrated into the field.  This is a plant that I have noticed being used as an early season host by caterpillars of the State Endangered Unexpected Tiger Moth, Cycnia inopinatus.


Second brood Unexpected Tiger Moths are found on Butterfly Weed.  Butterfly Weed is common in this field and I saw several of the bright orange caterpillars.  I only stopped for a few pictures, because I kept telling myself to get back to work.

Wednesday, August 13, 2014

Bones

I always experience a little burst of excitement when I find a skeleton.  This may be a carryover from my Elementary School days when I had visions of becoming a paleontologist, or it could be from my Junior High period of reading everything I could about adventurous archaeologists/treasure hunters searching for amazing discoveries.  In the books, treasure usually wasn’t far behind the discovery of a skeleton.  I found this wonderful specimen in the midst of a cedar thicket.


Many times you can identify the species, or at least the genus, from the shape of the skull.  Opossum was the first animal that came to mind when I saw the shape of this skull.


The size however, indicated a much smaller animal.  This is only about half the size of a typical Opossum skull.


The skull holds the key to identification in the form of a dental record.  Using the pattern of dentition, the range of possible animals can be narrowed considerably.  Step one is to determine the total number of teeth.  Here we have a total of 20 teeth in the upper jaw.


A check of the lower jaw shows 10 teeth on one side, so doubling that gives us a total of 20 lower teeth.  That tells us to suspect mammals with 40 total teeth.


There is only one native Ohio mammal with a total tooth count of 40.  That is the Raccoon.  The trouble is that this doesn’t look like the skull of a Raccoon.  Total tooth count helps narrow your search, but to fine tune or verify a choice, you need to look at the dental formula.  That formula takes the total number of teeth and breaks it down into the number of incisors, canines, premolars and molars in the upper or lower jaws.  One side of this upper jaw appears to have five incisors in front of the long canines.


A closer examination confirms that fact.  The jaw clearly contains five incisors on each side.  Raccoons only have three incisors per side, so this is clearly not a Raccoon.  Browsing through the dental formulae reveals only one mammal with five incisors to a side and that is the Opossum.  So, why the small size and only 40 teeth?


This is apparently the skeleton of an immature Opossum.  A close examination of the lower jaw reveals undeveloped teeth that have not yet emerged.  Many mammals do not get their full complement of teeth until maturity.  Had this little fellow survived a few more months, it would have acquired all 50 teeth characteristic of the species.  Proper identification of most living things requires consideration of many details.  Don’t be eager to make an identification based on just a single point.

Monday, August 11, 2014

Pulling Sweet Clover and Other Invasives

During the time of active plant growth in the prairies, I try to avoid management activities that are likely to disturb the Blue Jay Barrens flora.  Jobs such as mowing or the cutting and dragging of brush are performed during the fall and winter, when the plants are in decline or already dormant.  There are some jobs however, that must be done in the middle of the growing season.  One of those is the removal of Sweet Clover from the fields.


Sweet Clover is a tall growing biennial invasive plant that can overtop and out compete many native species.  This prairie opening was once the site of a healthy infestation of Sweet Clover.  Annual removal of the invasive species prior to seed development has resulted in a site that is almost clover free.


Two species of Sweet Clover, White and Yellow, are found at Blue Jay Barrens.  Yellow is the earlier bloomer, but White is not far behind.  The most effective method I have found of dealing with this plant is to physically pull it from the ground.  Clover pulling season begins around the last week of June and continues into late July.  I search through the open field areas and remove every Sweet Clover plant I can find.  This has been an annual activity for several years and in most locations the clover is present only as widely scattered individual stalks.  It’s fairly easy to move around the field and deal with the clover without trampling too much of the surrounding vegetation.  During my first few years of this activity, the clover was so abundant my trampling gave the appearance that a herd of cattle had run through the field.


I also pull a few other invasive species while targeting the Sweet Clover.  Queen Anne’s Lace is another biennial that can be effectively controlled by annual plant removal.  Some people prefer the name Wild Carrot, but I think that name makes it sound like the plant somehow belongs here.  I prefer a name that reminds of its exotic origin.  Now that the Sweet Clover is so reduced in number, I can give more time to removing the Queen Anne’s Lace.  I also pull Oxeye Daisy from the more established prairie areas.  Older Oxeye Daisy plants, those that have begun to send out rhizomes, cannot be pulled without leaving growing bits behind.  During its first year of growth, the plant is composed of a single stalk and its associated root system and can be removed in its entirety.  Hopefully I’ll be able to stop Oxeye Daisy from moving into new territory.


All of the pulled plants are deposited onto one of the established brush piles.  There’s always a chance that some of the plants have been able to develop viable seeds prior to being pulled, so I don’t leave any pulled plants in the field.  If there are seeds in the bunch, they will fall down through the brush pile and have a very poor chance of ever producing a mature plant.


I was particularly troubled to discover Crown Vetch growing in one of the prairie openings.  Crown Vetch is a notorious invasive plant that was once commonly planted on steep road banks.  The road bordering Blue Jay Barrens was so treated in the late 1970’s and I am constantly dealing with Crown Vetch flair-ups in the fields near the road.  The really disturbing part about finding Crown Vetch in this location is the fact that this opening is far from the road and in a watershed that does not come close to the road.  When an invader comes from an identifiable source and travels a particular route, such as down hill or down stream, you can anticipate where it is likely to occur and plan for those events.  An incursion this far outside the predicted pattern makes me fear that Crown Vetch could be a threat to any part of the property.


Crown Vetch is a perennial plant that can not be controlled by pulling.  The stem has a weak point at ground level that allows it to break away rather pull up the roots.  The roots are left in place to grow a new plant.  This is a common feature of many plant species and allows them to survive in areas that receive heavy grazing pressure.  If this infestation was in an old crop field, I would just spray it with glyphosate.  Being in an area that I consider a higher quality prairie, I didn’t want any collateral plant damage.  I chose to clip the Crown Vetch stalks about an inch above the ground and apply concentrated glyphosate directly to the stump. This is a more tedious process, but the result is the death of the vetch and an unblemished prairie.


Some of the old crop fields, especially areas near the house, present a slightly different set of problems.  There is a point where the quantity of Sweet Clover makes hand removal impractical.  If this little corner was the extent of my management area, I could certainly wade in and pull each one of those thousands of clover plants.  This calls for a different management strategy.  In order to reduce the number of clover plants, the plants must be denied the opportunity to produce seed.  An alternative to pulling the entire plant is the removal of the flower.  I accomplished that task on June 16 by mowing this part of the field.


At the time of the mowing, I wondered how much the clover plants would regrow after being cut.  So far, the clover has failed to return.  The native plants, primarily Indian Grass, are regrowing nicely.  Hopefully, mowing will bring the number of Sweet Clover plants down to a more manageable level.


I’m always watchful of biological controls that may be working on invasive plants.  This handsome caterpillar was busy munching away on one of the Yellow Sweet Clover plants.  I identified it as the larva of the Hitched Arches moth.  It appears that this moth eats a wide range of plant species and is not a super Sweet Clover predator.  It may not help me with my task, but it was nice to share the field with this small helper.