Monday, June 29, 2015

Edwards' Hairstreak Census

The Edwards’ Hairstreak butterfly is one of the Blue Jay Barrens rarities that has been the target of many of my management activities.  Each year, in late June, I take a day to search the property for this small butterfly.  Things have changed considerably since I first found the species here more than 25 years ago.

Edwards’ Hairstreaks are strongly attracted to the orange flowers of the Butterflyweed.  Fortunately, the blooming season for this plant coincides exactly with the flight period of the butterfly.  As part of my search, I check every Butterflyweed I can find.  Last year I was impressed to find many flowers with two Hairstreaks visiting at once.  This year there were frequently three butterflies per flower head. 

Not every Butterflyweed had an attending Edwards’ Hairstreak.  The butterflies stay in close proximity to their larva food plant, Blackjack Oak.  I have been doing what I can to encourage the growth of Blackjack Oak in the fields and now have these oaks growing in several places that they had not been before.  In each of these areas, I’m now finding the Edwards’ Hairstreak butterflies.

This is the original site of the Edwards’ Hairstreak at Blue Jay Barrens.  Even here, the population size has increased through the years.  The caterpillars are generally found on the small, three to six feet tall trees.  Fortunately for the butterflies, the harsh growing conditions in this shallow soil causes the trees to die back during dry years, so the trees tend to stay perpetually short.

The butterflies are also found on and around the oaks.  Females will lay their eggs in the rough bark of the older branches of the tree.  So far, my efforts to photograph the egg laying process have been unrewarded.

Eggs hatch early in the spring and the caterpillars begin feeding on the tender, newly emerging leaves.  Later on, they feed on the larger leaves.  The evidence of their feeding remains through the summer. 

Male Edwards’ Hairstreaks select a courtship territory that they defend against other males.  Typically the territory centers around an oak that is suitable for receiving eggs.  Females entering the territory are pursued by the male in an effort to mate.  Butterfly numbers are trending upward and the territory they occupy continues to increase.  I like to think of these increases are indicators of the success of my management efforts.

I’ve included a short video of a male taking off from an oak leaf to chase away an intruder.  There were so many males in close proximity that a chase by one caused an encroachment on another’s territory, so there were often several individuals involved in the chase.  This video can also be viewed on YouTube by clicking HERE.

Wednesday, June 17, 2015

Blue Dasher Dragonfly

I love to sit on the front porch and watch the dragonflies chase around above the Water Garden.  The Blue Dasher is an abundant and entertaining member of the group.

Males of the species are most noticeable as they perch on vegetation near the water.  They will typically choose the highest point on a plant stalk from which to sit and observe, but when the rushes bend down the dragonflies will take a position on the highest point of the arc.  From this vantage point they will rush out to capture small flying insects or chase away rival males.  There are so many things that need chasing that the males are seldom still for very long.

The females are more secretive and less often seen.  They will perch to watch for suitable insect prey, but they don’t go in for the aerial acrobatics associated with protecting a territory.  That and their more drab coloration, tends to keep them from being noticed.

A female hovering close above the water usually indicates an individual searching for a suitable location to deposit eggs.  The downdraft from her wings produces a pattern of rough water similar to that below a hovering helicopter. 

Egg release occurs when the female dips down and touches the tip of her abdomen to the water.  Several hundred eggs can be released a few at a time in less than a minute.  Each egg will produce an aquatic nymph that will stalk the depths of the Water Garden in search of aquatic prey.

This short video shows the female depositing eggs into the water.  The white eggs can be seen falling through the water after each dip of the abdomen.  Click HERE for the higher quality YouTube version of the video.

Monday, June 15, 2015

Water Garden Predators

The Blue Jay Barrens Water Garden will be celebrating its 15 year anniversary this summer.  On August 4, 2000 I installed a liner into the completed excavation and diverted runoff from downspouts in the front of the house to the leak proof pool area.  Two days later, a light rain put an inch of water in the bottom of the pool, and that night, treefrogs deposited several egg clusters.  Since then life in the pool has been in a state of constant change.  Each year is a new experience with new players, both plant and animal, finding a place in this tiny pool.  Most conspicuous in the pool these last few years has been a growing number of predators that feed on the masses of small animals attracted to a permanent body of water.

All plants in the Water Garden are native to this area, with the exception of the Water Lilies.  I’ve had a desire for a pool of Water Lilies for most of my conscious life, so I bought some tubers, planted them in weighted tubs and put them into the Water Garden.  After a couple of years, the Water Lily root mass grew so large that it floated the pots to the surface.  My thought was to transplant the tubers into larger pots with heavier weights, but when I hauled the plants out of the water I found that the lily roots had completely enveloped the pots.  I settled for adding more weight by strapping bricks around the outside of the root mass.  This worked for a couple more years, then up came the root masses with all of my bricks neatly hidden inside.  At that point I decided to just leave the lilies alone.  Now the root masses rise to the surface each summer with the growth of new roots and then sink again in the fall as the roots die back.  Islands created by the root masses are becoming populated with a variety of aquatic plants that don’t mind a winter long emersion.

In last few days there has been a mass emergence of damselflies from the pool.  The shed skin of the aquatic nympth is left behind by the newly emerged adult form.

Both the aquatic and adult forms of damselfly are predators.  Adults capture and consume small flying insects, while the aquatic nymphs feed on insects, tadpoles, fish, worms and anything else small enough to be captured and held.

Adults seem to emerge most often under the cover of darkness.  In the morning, newly emerged individuals can be found resting on stable structures near the water.  It takes a while for the wings and exoskeleton to harden, and for the full coloration of the adult to develop.

Unlike most other damselflies, Spreadwing Damselflies hold their wings slightly apart.  These damselflies are slightly larger than the average.

This is one of the Bluet Damselflies.  This is a small, delicate Damselfly that is quite common here at Blue Jay Barrens.

Male and female bluets join in tandem for mating and egg laying.  This pair is insuring a supply of Damselflies will be around next year.

Aquatic plants growing in pots set on a shallow shelf at the edge of the Water Garden have long since escaped confinement and found their own anchorage.  A tangle of rush stalks and other dead vegetation give a foundation for an assortment of water loving vegetation.  Some were planted when the Water Garden was first filled, but most have arrived by more natural means.

The thick vegetation may be a place of safety for some, but it also harbors a healthy population of predators.  These young spiders have just recently emerged from heir silken egg sack.

Most of these will fall to larger predators or relocate far distant from here, but several will stay and grow to adulthood in the lush vegetation of the Water Garden.

Red-spotted Newts are the top of the line submerged predator.  They can detect the slightest movement and will investigate any creature their own size or smaller.  If they can fit it in their mouths, they will eat it.  I don’t believe you can stuff a newt so full that it would stop trying to eat more.  Males like this one are continually cruising the pool looking for food and for breeding opportunities.

Female newts typically remain more hidden, but they are still alert for anything that may be food.

When newly hatched, salamander larvae are heavily preyed upon by the newts.  As the salamanders  grow, they become a predator as efficient as the newt.  The difference between the two is that the salamander only spends a portion of its life in the pool.  It will soon mature into a land dwelling form and take off for a more terrestrial lifestyle.

Bullfrogs are probably the most aggressive above water predators in the Water Garden.  As long as he can avoid the notice of Minks, Raccoons and Herons, this guy should have no problems.  Anything smaller than this guy’s mouth is in danger of being eaten.  Bullfrogs are typically just temporary visitors and after a few weeks will move on to new hunting grounds.  If it ever rains here again, this frog will probably move on.

Adult Green Frogs have a chance of competing against a large Bullfrog, but those that have just recently transformed from the tadpole stage are just Bullfrog food.  This young frog has just lost the last of its tail stub and is watching for a flying insect to come within grabbing distance.

Gray Treefrogs have a tough time competing in a permanent pool.  Predators make quick work of the newly hatched tadpoles and the adult frogs are in danger of becoming a Bullfrog meal.

Northern Water Snakes will also make a meal of tadpoles and frogs.  There are at least two mature water snakes now living in the Water Garden.  They arrived here as youngsters several years ago and have been growing steadily since.

I’ve resigned myself to the fact that the Water Garden has become a home for top level predators.  That is why I’ve initiated other projects to provide temporary pools to those aquatic creatures that cannot deal with a high predator load.  I’ll just keep enjoying the Water Garden and see what comes next.

Friday, June 12, 2015

Indian Hemp Theatre

You can find a wide variety of interesting creatures by searching across the hills and valleys, but sometimes it’s more productive to stay in one place and let the animals come to you.  All you need is some type of attractant, and some of Ohio’s native flora provide the best attractants around.  Flowering species that form small collections or colonies of plants can bring in swarms of animals intent on availing themselves of a meal of nectar.  One of the first of these to open its flowers at Blue Jay Barrens is the Indian Hemp, Apocynum cannabinum, sometimes referred to as Hemp Dogbane.  Insects swarm these plants as soon as the first blossom opens.

Opening of the Indian Hemp flowers usually coincides with the emergence of Great Spangled Fritillary butterflies.  These butterflies will nectar on a wide variety of flower species, but a concentration of desirable flowers in a small area will draw in a larger proportion of the hungry butterflies.

Swallowtail species can’t resist the lure of the hemp.  This Tiger Swallowtail has lost a bit of its wing, but it is still a strong flier.

This is the summer form of the Spring  Azure.  This is one of those species that has multiple broods through the year with seasonal variations between the broods.  These small butterflies are often taken by spiders and other predators that lurk among the flower clusters.

The Silver Spotted is my favorite among the skippers.  It’s nice to find a brightly colored, impossible to misidentify individual within a group that harbors so many difficult to separate species.

Even though this specimen of Southern Cloudy Wing is clearly marked, variations among individuals can make their appearance intergrade with other related species.  Identification can be difficult, especially when your camera shots don’t show the best angles or all of the necessary details.

Then you have the skippers that just don’t show much in the way of patterns or markings.  Species descriptions that include phrases such as “a little more orange than the preceding species” or “tending to be more gray brown than light brown” don’t often leave me with a feeling of satisfaction at my final identification.  I called this a Tawny Edged Skipper, but I have four more shots of the same individual and the differences of each shot could lead one to believe that more than one butterfly was involved. 

Peck’s Skipper demonstrates that a few skipper species have the decency to be clearly marked.  Regardless of your identification skills, Indian Hemp brings in plenty of these little speed demons of the butterfly world for close for viewing.

Butterflies may be most noticeable at the Indian Hemp flowers, but bees are by far more numerous among the blooms.  The large Bumblebees are certainly the most conspicuous bee visitors.

Most numerous of the bee species are the small solitary bees and wasps.  These little guys may be the most effective pollen movers around.  I’m partial to the green ones.

I seldom encounter the non-native Honey Bee at Blue Jay Barrens.  Most years will produce a random Honeybee or two, but there are occasional years when I see none at all.  I think it’s a shame that this species is what so many people think of when hearing the words bee or pollinator. I am personally more concerned about the plight of our native bee species.

Some species are attracted to the Indian Hemp plant itself.  This is the Dogbane Beetle, a brightly colored species that depends on this plant for its survival.

The life cycle of this species is tied to the Indian Hemp.  As an adult it feeds on the leaves and other plant parts.  Eggs are laid on plant stems and the hatching larvae move into the ground to feed on the plant roots.  Larvae pupate in the soil and adults emerge to feed on the developing plant.

Soldier Beetles show up as soon as the Indian Hemp flowers begin to open.  They will remain until the last of the flowers is gone.

They seem to spend most of their time either eating or reproducing.  Sometimes both at once.

This Soldier Beetle has fallen to an attack of one of the zombie fungi, Entomophtyora lampyridarum, that infects the body and causes the beetle to anchor itself to a leaf or stem near the high point of the plant.  Once anchored, the beetle spreads its wings and dies.  Soon the fungus consumes the body and sends out fruiting bodies that scatter spores to the wind, some of which will infect other beetles.

Another species of Soldier Beetle, doing what Soldier Beetles do.

Wherever animals congregate to eat or drink, there are predators awaiting their chance to grab a quick meal.  Adult Ambush Bugs fly in to the Indian Hemp flower clusters and hide themselves among the blooms.  When a nectaring insect comes near enough, the Ambush Bug impales it with the hooked claws at the ends of its forearms and drags the captor in for consumption.

Many interesting flies visit the Hemp Dogbane flowers.  This is a Feather-legged Fly, Trichopoda pennipes.  It feeds on nectar as an adult, but the larva spends its life as a parasite of Squash and Stink Bugs. 

In flight, the Feather-legged Fly displays the features that contributed to the decision on its common name.  I like to think of stands of plants such as the Indian Hemp as small outdoor theatres.  The flowers form a stage that host a non-stop run of entrances and exits from a never ending cast of fascinating characters.