Winter for the Birds

Hermit Thrush

Looking out on our backyard I could watch robins, cardinals, bluejays, wrens, doves, house finches and sparrows taking turns at the heated birdbath. Barb has created an island of 100 native plant species in a neighborhood sea of sterile mowed yards. While the plants are barren except dried seed heads which the finches feast on, they still provide a degree of shelter while waiting their turn at the feeder

As we tell the WOLF students, "Everything has to survive winter.....or else..." Whether by hibernation, migration or adaptation, every living thing has to survive winter or go extinct.  Our migrants have already left for their southern vacation and the only bird that hibernates is the Common Poorwill which doesn't live in Missouri. That leaves the hearty adapters that we see around our feeders.

Although several sources say the Poorwill hibernates, it actually goes into torpor.  Three things differentiate hibernation from torpor. Hibernation is voluntary, is driven by shorter daylight hours, and waking up can take hours and use a lot of energy. Torpor is involuntary, and results from falling temperatures (regardless of daylight hours), and the animal wakes rapidly by shivering, which expends energy, but conserves a lot more than hibernators use.

There are things that we advanced bipeds can do to increase their odds, improving their quality of life and benefiting from watching them in winter. You can keep water sources open, provide higher energy feeds (suet, black oil sunflower, shelled peanuts, etc.), and maybe leave a little extra on the ground for squirrels if using squirrel “proof” feeders.

Photo - Steve Martin

Teeth marks- click to enlarge

 

 

 

 

 

 

 

 

 

Down on Bull Creek it is time to hang up the feeders again. A bear on our deck reminded us this year that we hung up our feeders a little too early. It tore down a feeder hanging on a wire five feet above the deck, leaving its tooth prints as dents in the hard plastic. Now that Bruno is hibernating, or at least doing the intermittent Missouri version, it is time to hang them out again.

On our deck above the creek a lot of other critters don't understand the "bird" part of bird feeder. We have a special squirrel feeder with a spring bar that closes the feeder when any weight is on it. The squirrels have learned to put a paw in first to keep it open while they gorge. For a while we had a battery operated feeder that was supposed to give a little shock to a squirrel. I took it down before these smart little rodents could run a wire out to an nearby drey for lighting.

 

 

My favorite visitor was this opossum.  I was able to walk out on the deck and get within two feet of it for closeup photos before it turned around and got back to business licking the suet feeder.

Bill Bryson says: "Life just wants to be."  Lets help it all the way up and down the food chain.

Owl Pellets

I received a gift of owl pellets from Ben Caruthers.  While this might not excite you, it got a rousing welcome from our friends in the 5th grade WOLF School.  I asked Ben for the backstory.

"The barn is on a cattle ranch where my father-in-law works as a cowboy. I asked the owner if I could place an owl nest box in the old barn. I had not seen any sign of an owl. This was just in the hopes that an owl would find the box and nest there. At the same time I placed a trail camera to monitor any bird activity. It took two years, but the barn owls finally showed up."

There has not been any sign that they have actually nested in the box, but they used it as a perch.  Several other birds have shown interest in the box including rock pigeons, European starlings, American kestrel, and squirrels. Turkey vultures have used the barn for nesting. Once when I went to check on the nest boxes there were two large, white turkey vulture nestlings. They spread their wings and hissed when I approached. I got out of there quickly so I didn’t disturb them further. I also didn’t want to experience their alert response. 

The most recent check I made of the owl box I got to see the barn owl above in person. It flew right over the top of my head!"

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Ben collected over one hundred owl pellets on the floor of the barn below the nest box and from two other cross beam perch areas.  He delivered them to me separated in paper egg cartons.  Note to self - don't eat any eggs shared by Ben.  The contents were dry for months and some had been cleaned by some clothing moth larvae described in this previous blog.

Barn owls are carnivores, specializing in mice, moles, voles and birds.  Since they swallow their prey whole, passage of bones through the intestine is impossible.  Even the thought of that hurts!  The food bolus goes first into a glandular stomach for digesting with enzymes, acids and mucus.  Next, on to the muscular stomach (gizzard) where it is mechanically mashed up and the digestible portion move down the tract.   Fur, bones, teeth and feathers are retained until they are hungry later when they will be compressed into a "pellet" pushed out.*

By now, I am sure you are anxious to see what is in a pellet. The photo above is a single pellet which also had some leg bones, ribs, etc.  With the charts below* you can begin to determine which rodents passed on (or in this case passed up) after encountering an owl.   Biologist can even survey rodent populations by studying the pellets in the area.

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* Hungry for more details?  Check out this World of Owl site.  More on studying owl pellets is at this site.  A key to identification is here.

Scorpion

 

This is a vicarious two-part digital field trip to Rocky Barrens Conservation Area with Kevin Firth and Chris Barnhart.  This find led me and the WOLFs on a deep dive.

They photographed this cute little creature which has the typical features of a scorpion, immediately recognizable to most of us who have never seen one in the wild.  It has a long tail with a stinger curved over the body and large pincers in front like a beached crayfish.  

This is a striped bark scorpion, Centruroides vittatus, the most common and widely distributed scorpion species in the US.  MDC says "This is the only species of scorpion in Missouri. It occurs in glades and other dry, warm, rocky areas, and sometimes in buildings and shelters and under piles of wood, brush, or garbage."

Scorpions are arachnids like the ever popular spiders, ticks and mites.They all have an exoskeleton and 8 legs unlike the insects' 6 legs.  They also have a pair of chelicerae for feeding and defense and a pair of multipurpose pedipalps.

They consume soft-bodied prey such as spiders, cockroaches, ants, crickets, beetles, and butterflies. Grabbing the prey with their pincers, they sometimes use their stinger to subdue it. 

The tail and stinger was familiar to me from childhood where every cowboy worth his saddle would encounter them in the movie westerns.  Although they had a deadly reputation on film only 25 of the 2,500 known species have venom capable of killing a human.  Usually a sting is mild although allergic reactions can cause more severe problems.  Mexico on the other hand is one of the most affected countries, with the highest biodiversity of scorpions in the world, some 200,000 envenomations per year and at least 300 deaths.*

I enjoy Fun Facts just like my 5th grade WOLF School colleagues.  Here are a few:

• Their hard exoskeleton is fluorescent when viewed under ultraviolet light.  Most species are nocturnal hunters and can be found with a UV flashlight at night.
• Unlike their other arachnid cousins, they are viviparous, meaning they give live birth.  The female hoists the young onto her back where they remain until their first molt.
• Scorpions have two eyes on the top of the cephalothorax (fused head and thorax), and usually two to five pairs of eyes along the front corners of the cephalothorax. While unable to form sharp images, their central eyes are amongst the most light sensitive in the animal kingdom, especially in dim light, and makes it possible for nocturnal species to use starlight to navigate at night! * 
  

*Wikipedia

Thanks to Kevin and Chris for the glade trip.  We hope to tag along again sometime.

Tarantula!

Chris Barnhart was hiking Rocky Barrens Conservation Area with Kevin Firth when he got these pictures of a tarantula.  Kevin goes there regularly to check on burrows that hold them, knowing which rocks to lift up where they are hiding.  

This is the Texas brown tarantula (TBT) Aphonopelma hentzi.  There are over 900 tarantula species world wide.  The MDC website says it is the largest spider in Missouri and the only species of tarantula found in Missouri versus 50 species in the US, mostly in the southwest.  The female's body length averages 2" so you can imagine the length of the legs above.

Tarantula in hole to left, note silk lining

Our TBT spends its days in its silk lined hole, predominately on rocky barren glades.  They use holes created by rodents and reptiles and provide their own lining.  Emerging at night to hunt, they predominately feed on crickets which they paralyze with venom, then chew while mixing their digestive juices with it before slurping up the liquid dinner.

After mating, the male pushes away vigorously, at times even causing her to fall on her back.  He is avoiding the female's attack as he is no longer useful except as dinner where he would be nourishing his future offspring.  He doesn't live long after that anyway so she likely considers him disposable.

She will lay out a sheet of silk and deposit her eggs with a nutritious fluid.  She then guards the egg sac and even moves it to maintain the best temperature.  Some tarantula species carry their egg sac for three months before the eggs hatch into the post embryo stage.  They remain in that sac that Cowels describes in Amazing Arachnids as "eggs with legs."  Once they absorb the rest of the egg juice they proceed to molt many times as they grow to adulthood.

Like all other arthropods, molting consists of growing a new larger cuticle under the old, then splitting out of the old outer coat with enzymes that break it down.  Molting also renews the inner surfaces, such as the mouth, as well as external and for a period of time they can't eat during each molt.  They are also softer and more vulnerable during this time.  The good news is that with molting they can regrow a damaged or missing leg. 

Fishing for a tarantula with grass

Kevin was able to draw this tarantula out with a strand of grass.  It grabbed on and he could slowly pull it out.  This requires some patience as their bodies are somewhat fragile.  They are covered with urticating barbed hairs that are stinging or irritating to the skin.  Some species can shake these loose when irritated and inhaling them can be dangerous so don't make a habit of sniffing a tarantula.

They are slow moving and near-sighted.  They sense the world largely through vibrations felt in another type of hair on their legs.  To escape they can move more rapidly but not with accuracy.   Many species are able to make sounds by rubbing their hairs on their legs together, called stridulation similar to crickets and some other insects.

*Fun fact.  Female TBT have been known to live 30 years.  Chris raised one as a pet for 10 years early in his marriage to the ever-patient Deb. 

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This is a vicarious two-part digital field trip to Rocky Barrens Conservation Area with Kevin Firth and Chris Barnhart.  Next up, the Striped Bark Scorpion Centruroides vittatus.

Red Velvet Mites

Our WOLF School field trip last week included hiking down the old Mail Trace Road looking for little things in the woods.  Almost every student found one or more of these small things crawling slowly in the leaf litter, red velvet mites ( RVM). They are also called "rain bugs" because they come out after a rain like we had earlier. 

Mites are arachnids as are spiders, harvestmen, scorpions and the ever popular ticks.  Like ticks they have six legs in the first instar, then graduate to eight legs from then on into adulthood.  RVMs are members of the Trombididiidae family of mites which gives us several thousand species to choose from.  

You can see "velvet" close up.

Their lifecycle is complicated, beginning as eggs and then several inactive pre-larval stages.  The final larvae are parasites on insects and spiders (but not us mammals!)  The adults feed on the insects or their eggs, then mate and produce eggs for the next generation.

RVM are not chiggers and it is hard to find good reputable photographs of real chigger mites. There are several species with the blood-sucking habit, the most common being Trombicula alfreddugesi.  Their larva sticks its proboscis into our skin and injects digestive juice which hardens into a tube called a stylosome, the source of the itching inflammation as described here by Missouri University.

Wikipedia

Chigger mites on the other hand are tiny, requiring a magnifier to see them.  I doubt if anyone reading this has ever seen the mite.  Only the 6 legged larval stage is parasitic, feeding on reptiles and birds. The MDC Field Guide tries to reassure us that "mammals (including people) are secondary, almost accidental hosts."

"Their presence is best known, instead, by the intensely itchy welts they leave behind, usually where your skin is thin and tender (ankles, backs of knees, about the crotch, under the beltline, and in the armpits) and where tight clothing proves an obstacle to them (as where a belt or elastic band limits their wanderings).  Chigger bites sometimes have a tiny red dot at the center, which is the remains of a scablike tube your body formed in response to the chigger's irritating saliva."

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The Bug Lady has in depth information on RVMs and their interesting mating habits at this link.

A Fungus Among Us

I had these photographs of a moth with a bad hair day sent to me several years ago and just got around to identifying them.  I have lost track of who sent them but the story was too good to pass.

I had identified it as a fungus, Akanthomyces tuberculatus species complex on an unfortunate moth. My understanding was that the fungus parasitizes the host, eventually killing it, then acts as a saprobe, feeding on the corpse. When it is finished, it produces projections which are covered with asexual spores to find another victim.  I sent it off to our staff mycologist.  He takes the story over from here:

Mark Bower:

You are correct about what has happened to that poor moth. It came into contact with an Akanthomyces (tuberculatus or aculeateus, don’t know which one) spore. the spore stuck to the moth’s body, germinated, penetrated the body cavity, then devoured it from the inside. After the fungus was finished with its meal, it sent up spore-bearing structures as seen in your photo.

Below are a few Bull Creek examples of entomopathogenic fungi (a fungus that kills or disables insects).


Pupa infested with Cordyceps militaris

There are over 1,000 known species of entomopathogenic fungi which parasitize or infect insects. Most of these fungi are capable of infecting multiple insect species, but some are species specific. Your example represents a pretty straight forward lethal infection, but it isn’t always this simple. 

Bavaria bassiana which has killed a wasp

O. unilateralis-Wikipedia

Numerous fungal species not only parasitize and kill their hosts; they are actually capable of altering their behavior prior to their inevitable deaths. The most well-known example is Ophiocordyceps unilateralis, a tropical fungus which infects carpenter ants. After entering the ant’s body it attaches to it’s muscles and basically takes over its motor function. It then produces chemicals which somehow affect the ant’s brain. The combination of the altered brain function and the fungus’ control of the muscles cause the ant to climb a plant and permanently clamp its jaws on the vein of a leaf. Remarkably, at noon, the infected ants climb to 25 cm from the ground, and do so over the top of one of the ant colony’s trails or nest. The fungus then sprouts from the ant’s head and rains spores down on the unfortunate ants below. 

The previous story is bizarre, but this type of fungal-insect interaction is actually fairly common. Male periodic locusts can be infected by a fungus which devour it from the inside, all the while producing chemicals which cause the males to be hypersexual, so they buzz around trying to mate with every locust (male or female) that moves. This behavior enhances spore dispersal. Also, some species of flies can be infected, causing them to land on the top of a plant (such as a blade of grass), raise their butts upwards and die. This position enhances spore dispersal.

Torrubiella arachnophila which has devoured a spider

Editor's note:

Thanks to Mark Bower, I will now be worrying about a zombie fungus every time I climb to any heights.

Slime Molds

Today's blog is by the our award winning photographer of fungi, Dr. Mark Bower.  I asked him to tell us a little about slime molds, with added comments in italics by your editor.

For lack of a better idea, Slime Molds have been placed in the Kingdom Protista along with amoebas, algae, kelp and other oddballs. They spend most of their lives as single-cell amoeba-like individuals, oozing around in soil, feeding on bacteria and fungal spores. Yummy, delicious.

They are extremely common- one pinch of forest soil may contain around 50,000 individuals. They have been found in a wide variety of ecosystems, from the arctic to the deserts of Namibia. While they are virtually indistinguishable from amoebas, there is one important difference: unlike amoebas, Slime Molds, under certain circumstances, join together to form a completely new multicellular organism. In the case of the myxomycetes this new organism consists of a mass of slimy goo called the plasmodium.  No more barefoot walks in the woods for me.

Slime mold imitating a millipede

The slimy plasmodium creeps around, feeding and enjoying itself until it decides to stop and morph into its fruiting bodies, which produce its spores. If you think myxomycetes are weird, let me tell you about dictyostelids some day!  Be still my foolish heart!

Plasmodium of Ceratiomyxa fruticulosa

Here is the decidedly slimy plasmodium of Ceratiomyxa fruticulosa - the white stringy things are the developing fruiting bodies.  Grapes of wrath?

Mature fruiting bodies

While all myxomycetes have a pretty similar plasmodial phase, there is wide variation in the shape and character of the fruiting bodies. Here are just a few examples:  Who knew the words "slime" and "mold" could describe this kind of natural beauty?

Pretzel past its best used by date

Dead finger applauding Mark's pictures

Here is an entertaining three minute video that further explains slime molds.  Many more of Mark's slime mold photos are at this Flickr link.  Here is more from your National Park Service.

Thanks Mark, now off to dinner!

Owl Pellets

 

I recently was gifted owl pellets by Ben Caruthers. The dried undigested regurgitated remnants of an owl meal is an exciting exploration for a 5th grade WOLF student. I stored them in paper egg cartons inside a ziplock bag in the dining room. I have a very tolerant wife.

Exuviae of emerged moths - notice the wing features below

When I opened them a month later I could see exuviae, empty pupa cases with remnants where there had been wings developing. Among the collection of digested rodent bones, some of the debris was moving. After filming it, (a historic term for video), I extracted a wiggling piece of debris and captured a case-bearing larva attempting to escape as seen in this video.

 

The larva lives this stage of its life in a tunnel it glues together from debris.  The owl pellets in the egg carton had a least a hundred of these little guys.  Now the question was what were they?  

 

6 mm moth in owl pellets

A week later I had an answer.  I found several of these 6 mm long moths in the bag.  a quick Google search of "case-bearing moths" returned lots of links pointing to clothes/carpet moths in the Tineidae family.  The majority of these feed on fungi, lichens, and detritus, which fits with the material in these pellet remnants.

This is most likely the case bearing clothing moth, Tinea pellionella.  They are distributed world wide and are frequently associated with human populations.  There are a few other similar species in the family that can only be identified by examining their genitalia so we won't go into that.   

"T. pellionella larva eats mainly fibrous keratin, such as hairs and feathers. It can become a pest when it feeds on carpets, furs, upholstery, and woolen fabrics. It also consumes detritus, cobwebs, and bird nests."  -Wikipedia

The larva lives inside a snug case it constructs from debris such as fibers and hairs.  It extends its body to crawl around, hauling its home for protection.  Incredibly, it can turn around in the case to protrude its head and legs at either end and drag the case in either direction.  Finally they will form a pupa and eventually crawl out and expand their wings.

So back to the other question, what are owl pellets and why would a grown man collect them?  Owls often swallow mice, voles, small birds, and other prey whole.  After its gizzard has sorted out the indigestible parts such as fur, feathers, teeth and bones, the owl regurgitates them in a oval owl pellet.  This frequently occurs in a roost where they collect on the ground underneath.  Taking these to the 5th grade WOLF School, we students young and old, will examine them to try to determine what the owl had been eating. 

 

There are lots of resources available to students of all ages.  This brings out your inner 5th grader without having to get on a bus every morning.

Summer Egg Hunt #

Tonya Smith sent me on a non-Easter egg hunt with these picture of a string of barrel shaped eggs laid on a mulberry sapling leaf.  A search for insect egg photographs brought out a likely suspect, a leaf-footed bug, Leptoglossus oppositus.  A deeper dive found a picture of the critter in action below. 

Marina Martelli

The name leaf-footed bug comes from the shape of the tibia of many of the Coreidae family.  There are 88 species known in North America.   L. oppositus is extremely common across the eastern US and I find lots of them in the fields every year along Bull Creek.  

 L. oppositus is distinguished by the deeper scallops in the leaf-like feature of the hind tibia and the addition of three white spots across the hemelytra, the name of forewings in true bugs.

Proving the identification of the eggs down to species is hard but I would argue that the circumstantial evidence is strong.  Red mulberry is one of the host plants of the species as listed in BioOne.

Eggs closeup - Tonya Smith

Laying eggs - William Dedo

 

 

 

The eggs that Tonya photographed with their barrel shape and bulls-eye circle are fairly distinctive as seen at several sources.   Now enough of this hunt, it is time to go back to work.  No, not really - this isn't really work.

Rusty Spider Wasp

Building her nest - BC

Ben Caruthers comes through again with a great set of pictures.  He shot this red wasp and identified it as a rusty spider wasp (RSP), a lot easier to pronounce than its scientific name Tachypompilus ferrugineus.  This is a large and impressive wasp that dives into its work head first.

 

Click to enlarge - MDC

Spider wasps belong to the family Pompilidae.  These wasps visit flowers for nectar but their fame comes from killing spiders to feed the family.  The female stings her spider prey into paralysis and then drags the spider backwards to her nest, gripping the incapacitated spider with her mandibles.  The trip can be long and laborious as the spider is frequently much larger than the wasp.  Maybe that is why they call it going into labor?

With a wolf spider prey - Ted Kropiewnicki CC

Once the nest is prepared to her satisfaction, she grabs the spider and rolls it over so it is on top of her while she deposits a single egg before covering it with soil.  I frequently wonder how we know details like these but in this case it was observations by R.W. Strandtman described in this more detailed source.

The RSP specializes in collecting wolf spiders (Lycosidae).  Other species of spider wasps also tend to specialize in their spider prey, some with free living hunting species and others using web spiders.  The young wasp will get all its nutrition from this spider while all adults feed on nectar.

After this considerable effort to deliver and feed a single young, I wonder if she doesn't tell the next male that finds her, "Not tonight, I have a headache!"

Giant Walkingstick

I found this stick insect in the bed of my truck after emptying a load of cut branches.  This is a giant walkingstick,  Megaphasma denticrus, quite distinctive in coloration.  This is the longest insect in North America, reaching up to seven inches long.

It had a rough day and was missing one leg but that didn't keep it from climbing onto my hand and start heading upward, the only direction most stick insects want to go.  During the day they cling to the tree, sometimes swaying a little like a small branch.  Their defense is to drop to the ground and they are light enough to survive the fall.  Then they immediately start to climb up for food and shelter.  M. dentricrus adult's favorite food is oak and grapevine leaves.

This specimen is a male, defined by a large, single spine on the underside of its mid and hind femora, the first leg segment like our femur.  Another distinctive male feature is the clasper at the end of its body.

Copulation - Marvin Smith CC

Males tend to be smaller and far fewer than females.  The copulation consists of the male using his clasper to hang on to the female's genitalia, fertilizing the eggs as they come out and immediately drop to down to the forest floor.  The male may hang on for several days, eating during this time. 

The female may produce 150 eggs with three eggs per hour.  Her ovipositor has a small flipper which propels them randomly, ensuring that they are scattered and less likely to compete for vegetation.  (See ADW)

 

Clasping copulation - Marvin Smith cc

The young offspring feed on grass and leaves, particularly oaks and grapevine.  They will go through four to five molts before achieving sexual maturity.  This species is known to regenerate a missing limb but in this case I wasn't able to raise it long enough to make it to the WOLF School alive.  I think it died of a lonely heart, never having reached its biological imperative.

Ben Caruthers sent this incredible macro of its eye.  Now check this Bugguide link for more photographs.