Wednesday, June 22, 2016

Common Milkweed

Common Milkweed is now in full bloom at Blue Jay Barrens.  Common Milkweed has a strong network of rhizomes that allow a single stalk to become many in a short amount of time.  Milkweeds have just about surrounded the Water Garden this year.  I had to remove some stalks from the driveway and a couple more that were threatening to block access to the front porch, but there are still plenty left for the Monarch butterflies and other animals.

Milkweeds form a mass of flowers whose stalks all originate from the same point, a form known as an umbel. The large number of flowers found in each umbel typically cause the umbel to appear in the form of a sphere.

The petals fold back to reveal a central column of reproductive parts which is surrounded by a set of five two-part structures known as the hood and horn.  This arrangement has always reminded me of the old dental spit-sink with a hooked claw emerging from the drain.

Milkweeds do not produce the dust like pollen common in many flowers. To affect pollination, an insect carries a pollen mass, known as a pollinium, from one flower to another. A knot like affair joins two pollinia by short threads.  The insect’s foot or leg catches the thread and pulls the pollinia from a slit between the hoods. The photo above shows the location of the slit with pollinia still intact. Above that is a pair of pollinia that have been removed from the flower. I guess a flower needs to attract a wide range of insect visitors when pollination requires an incidental snagging of a pollen mass followed by the proper placement of that pollen mass on a new flower.

Milkweed flowers attract a wide range of bee species, from large…

… to small.

Some insects are attracted to the milkweed plant not by the flowers, but by other flower visitors. This is a Conopid fly.  Conopid larvae are parasitic on bumblebees. The Conopid adult will attack a bumblebee in the air, force apart two abdominal segments, and lay an egg in the abdomen of the bumblebee. The larva consumes the bumblebee from within over the course of a couple of weeks. The action of this parasitic consumption causes the bumblebee to dig a hole and bury itself before dying, providing the Conopid larva with shelter in which to pupate and overwinter.

Like many other insects, the Conopid Fly uses mimicry to help avoid predation. In this case the fly looks suspiciously like a wasp.  Would-be predators, fearful of a stinging response, are more likely to pass this fly by.  The easy way to tell the difference between a fly and a wasp is to count the wings. A wasp has two pairs of wings, while a fly only has a single pair. In lieu of the second pair of wings found on bees and wasps, a fly has a pair of structures known as halteres.  Halteres help to balance the fly in-flight. In the photo above, the two white objects at the rear of the thorax are the halteres.

Highly colorful Long-legged Flies flit about the leaf surfaces of many plants. The large milkweed leaves seem to particularly attract this insect.

It wouldn’t be a milkweed plant without Milkweed Bugs. Milkweed Bug pairs are often in mating tandem at this time of year. The reproductive process is not going to stop the upper bug from probing the milkweed flowers for a meal. The lower bugs is dragging around a pair of pollinia on its middle foot. The pollinia will be wasted if not deposited into an open flower.

Goldenrod Soldier Beetles are also busy with courtship rituals. These beetles are pollen eaters and will visit many species of flowers besides their namesake Goldenrods.

The milkweed flowers are brightly colored, strongly scented producers of abundant nectar. Most moth visitors appear after dark and are rarely noticed.  The Hummingbird Clearwing is one of the few brightly colored moths that visit the flowers during the daytime.

Many species of skippers are attracted to milkweed. This is the Silver-spotted Skipper, one of the largest and most easily recognized of that group.

Butterflies of all sizes visit milkweed. On the smaller end of the scale are the tiny hairstreaks, like this attractively marked Banded Hairstreak.

Great Spangled Fritillary butterflies have been mobbing some of the milkweed flowers. If your interest is in viewing butterflies, and other interesting animals, it’s worth encouraging a few Common Milkweed plants to live somewhere near your house.

Still photos don’t do justice to mobbing butterflies, so I offer the short video above.

Monday, June 13, 2016

Young Black Rat Snake

Black Rat Snakes were not particularly common when we first moved to this property 30+ years ago.  After a few years, snakes took up residence in our barn, garage and attic.  From then on, encounters with adult Black Rat Snakes became common.  It’s just been in the last couple of years that I have begun to regularly see youngsters.

I found this young snake perched on a leaning stake intended to hold up the side of a brush pile.  From this position, the snake had nowhere to go.  I think it was contemplating its next move as I arrived.

Young Black Rat Snakes have an overall grayish coloration decorated with a row of brown patches running the length of the back.  A hatchling leaves the egg with a body length of about one foot.  The pattern is most pronounced in the newly hatched specimens, but is slowly masked by dark pigment that develops as the snake ages.  At maturity, around four years of age, the snake will be about five feet long and predominantly black.  This individual measured at about 26 inches long.

Almost every young Black Rat Snake that I find seems to have a distinctive bulge of a recently swallow meal.  I always picture a mouse inside the bulge, but it could just as easily be some other small mammal, bird, reptile or amphibian.

After a moment of watching me take its picture, the snake turned around and headed down into the brush pile.  Somewhere in that mass of branches is probably where the cause of the snake’s bulge came from.

I found it interesting that as I entered the garage just minutes from having my young snake encounter, I came upon an adult Black Rat Snake patrolling the storage area in search of a tasty rodent meal.  This could easily be a parent of the youngster outside.

Friday, June 10, 2016

Red-headed Woodpeckers

Red-headed Woodpecker numbers continue to climb at Blue Jay Barrens.  There are at least five individuals that regularly visit the yard, and I frequently see others about the property.

Of course, the Red-headed Woodpecker has a ways to go before it displaces the Blue Jay as the most noticeable bird species here.

The birds are most easily observed at the feeder. 

Sunflower seeds are collected in quantity…

… and removed to nearby deadwood snags to be opened and consumed.

It’s generally just one woodpecker at a time at the feeder.  Others wait in the trees for their turn at the seed.

I’m becoming used to hearing the calls of these beautifully colored birds.  I hope the Blue Jay Barrens population continues to grow.

Wednesday, June 8, 2016

Snapping Turtle Laying Eggs in Ant Hill Again

It has been just over a year since I witnessed a Common Snapping Turtle laying eggs in an ant hill constructed Allegheny Mound Ants.  That was the first time I had seen an ant hill chosen as a nest site for turtle eggs.  Now the turtle is back and repeating last year’s performance. 

The female Snapping Turtle has chosen an ant hill about 50 feet from the one used last year.  This is a smaller mound, so the damage appears more extensive than what I witnessed before.  She seems to have taken off a significant portion of the mound top before feeling comfortable in digging out the egg chamber.

The ants are naturally disturbed by her intrusion and are trying their best to defend their home.  The turtle’s eye is probably the only place sensitive enough to be bothered by an ant’s bite.  Sight is not needed for the turtle’s egg laying activity, so the eyes can be kept closed to keep the ants at bay.

On the other side of her head, the ants are all busy futilely attaching the thick neck skin, so the turtle keeps that eye open.  She gave no indication that she noticed my presence.

The ants quickly abandon attacking parts of the turtle that do not move.  The turtle’s hind legs are targets of constant ant attack because they are continually moving to push the eggs into the nest chamber.

The turtle finished laying her clutch soon after I arrived.  I left when she began covering the freshly layed eggs.  I kept a watch on last year’s nest in hopes of seeing the emergence of young turtles, but I missed seeing that event.  I can attest that there was no evidence that egg eating predators bothered the nest.  Maybe the ants provide protection to the developing turtles.

This is the condition in which I find most Snapping Turtle nests.  I found the remains of this nest just hours after witnessing the placement of the ant hill clutch.  Maybe ant hills are the best place for turtle eggs.

Click HERE to read about last year’s turtle eggs in an ant hill.  Click HERE to view a video of last year’s egg laying event.

Friday, June 3, 2016

Eastern Towhee Nest

Eastern Towhee is a bird that I see year round at Blue Jay Barrens.  A few of the birds overwinter here and are occasional guests at the birdfeeder. Their numbers climb significantly in the early spring with birds that spent the winter at a more southern location. Over the years, I’ve seen many young birds in the care of their parents, but have never found an active nest. Until now.

This is the first towhee nest that I have ever found.

I was walking across this field when I flushed a towhee from the grass while stepping down the cut bank shown in the center of the photograph.

Birds don’t usually flush from under my feet unless they’ve been disturbed from a nest. I stared at the bank and the surrounding area but could see no evidence of a nest.

It wasn’t until I got within a couple feet of the bank that I found the nest tucked beneath an overhanging cascade of dead grass.

The female towhee was frantically calling from a nearby cedar, so I only lingered long enough to capture a few images of the nest. I’ve read that Eastern Towhee nests are highly parasitized by Brown-headed Cowbirds. I hope this nest avoids that fate.