Monday, July 17, 2017

Flood 2017 - Creek Impacts

The July 6 flood certainly had an impact on the creek.  Some sections lost all lose material right down to the bedrock.

Other sections accumulated material brought down from upstream.

Deposition of stone in the creek channel was due to the formation of debris dams that temporarily slowed the speed of the water.  As the water slowed, it lost the energy necessary to carry heavy objects and the gravel dropped out into the creek bed.

Water diverted out of the creek channel carried its sediment load along with it.  A number of sand bars were formed well away from the creek. 

Where the creek left its bed with more momentum, gravel bars were left behind.

There were even a few large flat rocks left stranded far from the creek.

At one bend in the creek the flood water cleaned the face of this bedrock arch.  This feature has never been so easy to view.

Water was deep enough that the meanders in the creek had little effect on the direction of flow.  The current went straight down hill, passing cleanly over every bend and curve in the creek channel.

It was not hard to tell in what direction the water was flowing.  I don’t think a steam roller could have laid these plants down any more than this.  This particular area typically has a nice floral display in late July.  I don’t think that’s going to happen this year.

In the broad, flat areas, water depth peaked at between two and three feet.  It’s going to take a couple of years before the visual effects of this flood event begin to disappear.

Wednesday, July 12, 2017

Flood 2017 - The Storm

Last month I was describing the drought conditions currently being experienced at Blue Jay Barrens. I believe it’s safe to say that that particular period of drought has come to an end. On July 6, Blue Jay Barrens was the recipient of 6+ inches of rain in a period of less than 12 hours. The resulting flood conditions far surpassed anything we have ever experienced here in the past.

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The rain began around 1:30 AM and continued until 8:30 AM. During that time approximately 3 ½ inches of rain fell. Our dry soils were able to accommodate most of that water and very little runoff occurred. The weather was clear for the next few hours, until a storm formed over the area around 12:20 PM. During the next hour, 2 ½ inches of rain was added atop soils which had nearly reached their saturation point. Runoff began immediately and the majority of that 2 ½ inches of water flowed overland across the landscape. The video above shows the runoff from a watershed only a few acres in size as it crosses the driveway in front of our house. The video begins during the most intense part of the storm and ends about five minutes after the rain stopped.

Even though I was dismayed at the magnitude of the disaster unfolding before me, I got some pleasure at viewing the scene shown in the photo above. The clear water coming in from the left is flowing from my field that has been managed for the past 30 years as tallgrass prairie. The muddy water to the right comes from neighboring properties and the Township road. When I first bought this property, all of that runoff water would’ve been muddy. It’s nice to see that my management efforts are having some positive effects.

The former access road, now grassed over, carries the excess floodwater past the prairie display garden and dumps it over the bank into the pond. Water from a more normal runoff event would all have gone through the shrubbery to the right.

With the pond’s primary spillway overloaded, water overtops the dam. This is something that has not occurred since I moved here.

During a year with more typical rainfall, the pond would currently be down to just a puddle and raccoons would be devouring the last of the tadpoles. Gray Treefrog tadpoles generally have a poor time of it in the pond. They breed later than most of the other frogs and the tadpoles generally don’t have time to fully develop before the water disappears. This flood event has been a boon to the Gray Treefrog population.

Thanks to all this water, I’ll be seeing many more of these newly morphed Gray Treefrogs during the next few weeks.

Wednesday, June 21, 2017

Wasps and Other Mud Puddle Visitors

During early afternoon on the day before the Toad Pool went dry, I spent a couple of hours photographing visitors to the rapidly shrinking puddle. During this session I concentrated more on short videos than on stills.

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A single, newly morphed toad is a couple weeks behind the hoard that emerged from the pool a few weeks ago. This little guy has only been a land dweller for a short time, but it already displays the mannerisms of an adult.  Click HERE for YouTube version.

The most noticeable visitors to the pool were wasps loading up on water. The wasps were light enough to ride the surface tension of the water as they drank.

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Several species of paper wasps took advantage of this dwindling water supply. A few mud wasps also flew in, but they all left with only water.  Click HERE for YouTube version.

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The paper wasp in this video doesn’t seem to be intimidated by the beetle larva attacking it from the rear. It’s probably a good thing the larva couldn’t get hold of the wasp, or it might’ve been pulled right out of the water.  Click HERE for YouTube version.

A small wolf spider stalked the mud flats.  It was particularly interested in the movement of what appeared to be a small insect near the edge of the pool. What wasn’t immediately obvious was the fact that the small insect was held in the jaws of a much larger aquatic beetle larva.

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The spider finally attempts an attack on the small insect, but is driven back when the beetle larva begins to thrash its head. Immediately after the head thrashing, the beetle larva scoops a small bit of mud into his breathing snorkel, located just to the right of the thrashing head, and shoots a mud ball at the place the spider had just been.  An interesting defense mechanism.  Click HERE for YouTube version.

Several butterflies took advantage of the wet mud to imbibe some mineral laden water. The most persistent of these was a common Buckeye.

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The temperature at the time this video was made was 93°F and there was a strong wind blowing. You can see the puddling butterfly occasionally buffeted by the wind. I was pretty much baked all the way through by the time I called an end to this photography session.  Click HERE for YouTube version.

Wednesday, June 14, 2017

Drought 2017 - Toad Pool

After several months of experiencing rain storms two or three times per week, the rain has stopped.  Three weeks of dry, hot weather has left the Toad Pool as nothing but a small patch of mud.  The last bit of open water disappeared on June 12.

The water level remained good until June 2.  That is when temperatures began reaching 90°F and strong, dry winds began to blow.  Under these conditions, you could almost see the pool growing smaller.

On June 5, an approaching storm front gave hope of some much needed rain.  When just a few miles away, the line of rain formed a gap that neatly slid over Blue Jay Barrens.  I could see the rain clouds to the north and south of us, but not a drop fell here. 

By June 8 the water depth was down to about two inches.  Forecast was for dry and windy conditions.  Fortunately, the bulk of the toad tadpoles had morphed into tiny toadlets by the end of May.  The pool had served its intended purpose well.

An interesting pattern was left behind by the tadpoles.  While feeding, each tadpole would work its way down into the mud as it searched out algae and other tiny food items.  The tadpole’s head would remain stationary and the body would rotate around that fixed point.  The result was a depression in the mud.  This pattern of dimples covered the bottom of the pool.

My photos of the depressions turned out to be good examples of the Dimple and Bump Optical Illusion.  Depending on how it is viewed, the pattern may appear to be a series of indentations or a series of raised bumps.  I can manage to switch back-and-forth between seeing dimples and bumps.  My wife sees only bumps, but she has taught High School English for 35 years so …

A mixed bag of mammals and birds have been visiting the pool for water and to take advantage of any food morsels left vulnerable by the shrinking pool.  Rain storms began moving through the area yesterday.  Flash flooding has occurred just a few miles from our location, but we have only managed to get rains just slightly stronger than a drizzle.  I hope this doesn’t continue as a summer long pattern.

Sunday, May 28, 2017

Edwards' Hairstsreak Larvae - Night Feeding

Within the Blue Jay Barrens prairie openings are a scattering of medium to small sized Blackjack Oaks.  Some of these trees are decades old, but various environmental factors keep them from getting very large.  Dry site conditions limit water available to the tree, White-tail Deer find them to be the perfect choice for rubbing antlers, Periodical Cicadas cause a dramatic die-back every 17 years and a wide variety of insects find the leaves extremely palatable.  I make several close examinations of these trees each spring as I follow the development of the Edwards’ Hairstreak butterfly larvae, one of those species with a dietary preference for Blackjack Oak.

Edwards’ Hairstreak eggs hatch just as the oak buds begin to swell in early spring.  The larvae feed on the buds and newly developing leaves.  On May 8, temperatures dropped to 29°F causing frost and freeze damage to many plants.  Damage to Blackjack Oaks varied between individual trees, but all suffered the loss of some new growth.  This was a setback for both the trees and the Edwards’ Hairstreak larvae.  Fortunately, buds were not affected and regrowth was rapid.

When I checked the Blackjack Oaks three days ago, the leaves were showing signs of heavy predation by the Edwards’ Hairstreak larvae.  When this magnitude of damage occurs to the leaves it is a good indicator that the larvae have reached their final instar stage and will soon be pupating.  At this point it does no good to search the tree for larvae, because they do not spend the day in the open.

Young Edwards’ Hairstreak larvae remain in the open feeding through the day.  When they become older, they feed only at night and spend the day at the base of the oaks, hidden in cavities constructed by Allegheny Mound Ants. 

Near sundown, the larvae leave their shelter and begin climbing the tree.

Each larva is accompanied by its own cadre of ants. From the time they hatch until emergence as adults, the Edwards’ Hairstreaks are accompanied by ants.  The larvae achieve a degree of protection from the ants and the ants receive a sugary Honeydew solution excreted by the larvae.

The larvae on the first tree went too high to be easily observed, so I switched my attention to a smaller tree that displayed feeding activity.  This tree was less than three feet high and struggling to regrow leaves killed by the freeze.

The larva’s head is located near the top of this photo.  As the larva eats, an ant visits honeydew producing glands near the larva’s tail.

It’s fortunate that pupation is near.  This tree was loaded with larvae.  At the rate they’re eating, the tree may soon be stripped bare of leaves.

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The above video is a compilation of several shots of moving and feeding Edwards' Hairstreak Larvae.  Make sure your sound is on, so you can enjoy the call of the Chuck-will's-widow while you watch.  This video, in a possibly clearer form, may also be viewed on YouTube by clicking HERE.

Wednesday, May 24, 2017

Toad Pool Success - Part 2

Blue Jay Barrens is experiencing an influx of thousands of young Eastern American Toads emerging from the still under construction Toad Pool 2. This little guy has fully absorbed his tail and, looking every bit like the adult version of his species, is moving away from the pool towards the open fields.

The pool experienced no shortage of water this spring. Frequent rains provided above average rainfall totals causing the water to regularly be at a level higher than intended.

Toad eggs appeared in the pond on March 29 and began hatching on April 2. By April 5 the eggs had completed hatching, but the tadpoles were not yet mobile and their pattern on the bottom of the pool continued to match the strings of eggs that had been laid out a week before.

After exiting the egg membrane, the tadpoles remain stationary for several days as they absorb their yolk sacs and mature into a more traditional tadpole form. Their first food will be the algae seen growing on the empty jelly strings and pool bottom.

Once they become mobile, with tadpoles migrate upslope to shallower water where the generally warmer temperatures will aid in their growth and development. Their initial efforts cause them to congregate atop the slightly higher mounds on the pool bottom.

A few days later their improved swimming ability allows them to reach the shallow water at the edge of the pool.

The unfinished condition of the toad pool caused an unintended broad expanse of shallow water to become available to the tadpoles.

The shallow area, which had been left smooth when construction was halted last fall, had become pocked with depressions caused by deer visiting the pool.

As water levels receded during uncharacteristic hot periods between rainfalls, the depressions became isolated pockets that rapidly dried after their connection to the main body of water was severed. Tadpoles caught in these depressions quickly perished.

Fortunately, I still retained the mud puddle engineering skills that I had honed as a child and was able to make periodic adjustments in the way of dams and channels to ameliorate the desiccation threat to the tadpoles. If weather conditions allow me to complete my construction activities is fall, the hazard should not exist next year.

Transformation from tadpole to terrestrial toad form began a week ago and is now proceeding at a rapid pace.

Once all four legs appear, the tail quickly shrinks and the young toad pushes himself free of the water.

It spends a day or two near the water’s edge before heading off to begin a terrestrial lifestyle.

The little toads are so numerous in the vicinity of the pool but I can’t walk in that area without stepping on a few, so I’m waiting until they’ve had a chance to disperse before checking the pool again. I’m looking forward to encountering these little guys through the summer. It will be two or three years before this year’s hatch is mature enough to return here to breed. By that time Toad Pool 2 will be completed and, with any luck, there should also be a Toad Pool 3.