Photo of the Week – June 1, 2018

I ran into a couple mysteries this week.  I enjoy mysteries, whether they get solved or not, but I’m wondering if maybe we can crowd source answers to both of these.  Stay tuned to the comments section for potential answers, and add your own suggestion if you have one.

First, when I was out at our family prairie last week, I found something interesting along the edge of our wetland.

Mystery #1. Who ate this bullfrog on top of this fencepost and left the remains hanging there afterward?

Something is helping us control our invasive bullfrog population, which I’m grateful for, but I’d like to know who to thank!  What kind of creature would pick up a full sized bullfrog, move it to the top of a nearby fence post and eat it?  The remains of another frog were on the next post over from this one, so it’s not an isolated event.  I’m thinking it has to be a bird, and a large one at that.  Herons like to eat frogs, but as far as I know, they leave the remnants floating in the water.  Do hawks eat frogs?  Owls?  Osprey?

The second mystery is a little different, and I’ve already had help solving part of it.  I’ve been walking past a couple New Jersey tea plants recently (on the way to my square meter photography project site).  Each time, I’ve noticed a particular kind of insect hanging around on and near the flowers.  The way the bugs (because they are clearly Hemipterans – true bugs) are sitting poised and apparently waiting for something, I’ve been assuming they are predators.

This bug, and several more like it, have been hanging around on a couple New Jersey tea plants lately.

I recognized the bugs but didn’t know what they were.  They reminded me of leaf-footed bugs, but instead of the flattened “leaf” structure being on their legs, this bug had them on its antennae.  I submitted the above photo to Bugguide and got a quick response, identifying it as a Euphorbia bug (Chariesterus antennator) – a kind of leaf-footed bug, after all.  That was easy, but my next step was to try to learn more about it, and that’s where I got stuck.

I found information on a couple other leaf-footed bugs, but not the Euphorbia bug.  It appears most leaf-footed bugs are plant feeders, with some doing minor damage to crops or garden plants.  Photos of the Euphorbia bug I can find on the internet often show it on Euphorbia plants (spurges), which makes sense, but I can’t find anything that says it actually feeds on spurge plants themselves.  Maybe that’s a favorite plant, but not its only food source?

So, I want to know what Euphorbia bugs eat.  Are they predators that hang out on plants waiting for opportunities to catch prey?  Or are they plant feeders that may or may not prefer spurge species?  While we’re at it, what do their larvae feed on?  Where do they live?  Is there anything else interesting about them?  Mysteries.

Help?

Well, Now, I Wonder…

People often seem surprised to learn that I’m an introvert – probably because in large groups, I feel pretty comfortable being the center of attention and talking to an interested audience.  However, when I’m just one of many people in a large gathering, I naturally retreat to the edges of the group where I don’t feel hemmed in by humanity.  As a result, during presentations out in the field, I tend to wander and explore while staying within earshot of what’s being said.  I’m not trying to be rude, I’m just keeping my escape routes open…

Accordingly, two of the three mysteries I wanted to share today were things I found while skulking in the background during a tour last Friday at the Valentine National Wildlife Refuge.  The first was a trailing wild bean plant (Strophostyles sp) with a series of intriguing holes in the leaves.  I showed a couple other people, but none of us knew what might have made the holes.  I’m guessing invertebrate, of course, but I don’t have any idea beyond that.  It looks to me like something was rasping away at the surface of the leaf until it punched all the way through and then repeated the process in a new spot.  Anyone recognize this?

Interesting holes in trailing wild bean leaves…

The second mystery relates to some piles of wild rose hip remains scattered around on the ground.  We were standing in the middle of a good patch of wild rose and talking about how plants in recently burned areas (at least this year) seemed to have lots of large fruits.  As I wandered around with my eyes scanning the ground, I spotted several places where some animal had apparently dismantled rose hips, leaving the skin (rind?  husk?) and seeds strewn about on the ground.

Rose hip remains.

At first, I was wondering why an animal would go through the trouble to open up the fruit and then not eat the seeds or skin since there’s not much more to the fruit than that.  Upon a closer look, though, it appears many of the seeds had been split in two, which makes me wonder if something was eating the center of the seeds and then spitting them out – almost like a ballplayer at a baseball game.  I’m guessing this is a small mammal, but don’t remember seeing piles quite like this before.  Help?

A closer look a the rose seeds, which seem to be split in half and hollowed out?

The final mystery was not something I discovered, but instead came from a question someone asked me.  I feel bad, but I honestly don’t remember who it was who asked – I’d give them credit if I did because it was a great question.  The question was, “Why don’t we see big flushes of annual sunflowers in the same place two years in a row, even when there is still plenty of bare ground?”  We’d been talking about the hypothesis that plains sunflower (Helianthus petiolaris) germinates really well when there is abundant bare soil – such as after a fire or drought.  However, the question asker rightly pointed out that it doesn’t seem like the same phenomenon repeats itself in the same location in the following year, even if those bare soil conditions still appear to be present.

Populations of plains sunflower, like the one our group explored in this burned patch of Sandhills prairie, don’t seem to flourish two years in a row, even when bare ground persists. There must be something else driving that population boom and/or restricting a subsequent one.

I don’t have an answer for that sunflower question.  Possible explanations could include 1) the majority of the available seed bank germinated the first year and seeds from that crop need a year or more to become stratified or otherwise prepared to germinate; 2) sunflowers produce chemicals that inhibit their own growth the next year (seems doubtful); 3) an insect, microbe, or other organism builds up large populations during population booms of sunflowers and then either eats or infects seeds/plants of the next generation, preventing them from establishing.  There are probably lots of other possibilities.  Anyone have the answer?

I’ve said it many times, and it’s always true – finding these kinds of mysteries is what helps keep me interested and excited about prairie ecology.  It’s fun to figure out the solution to the mysteries, but then I have to find more mysteries.  Fortunately, there doesn’t seem to be any shortage of them!

A Toadal Mystery

Ok, I need help solving this mystery.

As I was walking across a large concrete parking lot this weekend, I looked down and saw this:

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It’s clearly the imprint of a Woodhouse’s toad in concrete.  (Yes, I’m guessing on the Woodhouse’s part of that identification, but it’s a very good bet.)

The bigger question is, “How the heck did this happen??”

The print was more than 50 feet into the concrete from any non-concrete surface.  It was also more than a couple feet from the nearest seam between concrete sections.  I have several hypotheses.  If you’re going to disparage any of them, you’d better give me a better one.

Hypothesis A: A great blue heron or other large bird caught a Woodhouse’s toad in a wetland near town and was carrying it back to its nest as food for its young.  As the bird flew over the church parking lot, which was in the process of being poured, it was distracted by the sight of the rotating tub of a concrete truck and accidentally dropped the toad into the soft concrete of a section that had just been smoothed.  After the concrete dried, the deceased toad eventually decomposed or was carried away by a suprised scavenger.

Hypothesis B:  An adventurous toad living in an airplane hanger at the tiny airport north of town nestled itself into some nook or cranny in a small airplane before it took off.  As the plane lifted itself into the air, the poor toad, clinging to the plane with its white-knuckled front feet and flapping like a flag in the wind, finally lost its grip and tumbled several thousand feet into concrete that was nearly, but not completely cured.

Hypothesis C:  Jimmy, the son of Greg the concrete guy, had a pet toad named Harvey.  One night, Greg came home from a long hard day and dropped his jacket on the floor near the front door before shuffling off to a hot shower.  Later that night, Harvey hopped into the pocket of that jacket and decided it was a good place to nap.  Early the next morning, Greg hopped out of bed, refreshed and ready to make some more progress on the parking lot, grabbed his jacket and strode out the door to his truck.  Harvey, still asleep, remained in the jacket pocket.  About mid-morning, as Greg stretched his arm far across the patch of concrete he was smoothing, Harvey felt squeezed by the pocket, squirmed out, and plopped into the concrete.  A few moments later, Greg, who never really cared for Harvey anyway, spotted the toad glaring balefully at him from where he was stuck in wet concrete.  Greg considered his options momentarily before simply turning away to work on the next section of concrete.  The next day, Jimmy, after a long fruitless search of the house for his favorite pet, was presented by Greg with a black lab puppy, which cheered him up considerably.  Meanwhile, Harvey made his escape from the concrete after it dried, and hopped off into a nearby cornfield where he met the love of his life (several of them, actually).

That’s the best I can do.  Any better ideas?

Hubbard Fellowship Blog – Mystery Eggs

 

A guest post by Anne Stine, one of our Hubbard Fellows.  All photos are by Anne.

A couple of weeks ago (in mid-October) I noticed unusual egg cases about 2-3 inches off the ground on the base of Siberian elm saplings in one of our more tree-infested tracts.  I noticed the casings because I was basal bark treating their hosts. The placement of the cases and the size of the host trees were pretty uniform.  The egg cases themselves look like limpets and are about 1 cm wide by 2 cm long.  I know they’re egg cases and not cocoons because I snapped one open to see what was inside.

Egg case, with PVC kill-stick for scale.
Egg case, with PVC kill-stick for scale.

What species are these mystery eggs, and do they parasitize Siberian elms? If anyone has answers to these questions, I’d like to hear them.  It would be great if SOMETHING ate Siberian elms.  Combating invasive/aggressive trees is a major task here on the prairie. Deciduous trees are especially hard to kill.  Their root reserves make them more resistant to fire, and they sucker when girdled.  Because of these limitations, basal bark treatment (kill-sticking) in combination with removal of parent trees is often the most sensible course of action. Kill-sticking is problematic because it is extremely time consuming, and is ineffective on large saplings with thicker bark.  Here’s hoping these little eggs grow up to be hungry adults with a taste for elm!

Open egg case on rubber herbicide glove (for science!). Back-side up.
Open egg case on rubber herbicide glove (for science!). Back-side up.

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Egg case frontal view.
Egg case frontal view.

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