Countershading and Caterpillars--Hickory Horned Devil, August 27-31

I know it's been awhile since I posted a Hickory Horned Devil installment. Whoa it's been a busy fall! Thank goodness I took a few days to gather, edit, and upload all these photos so I could write the posts later. It takes forever to get them to load on my LTE-based Internet. Anyway, enough yangin'. I've got power and Internet, and that's a lot more than about a million Floridians have after that SOB Ian hit them.

This post covers a four-day span when the Devilworm was growing into its long silk stockings, getting more colorful by the day--even by the hour! 

27 August, 4:10 pm

Its face on 28 August. I love the little true legs clasped up under its chin like Dr. Evil!

The Alice in Wonderland comparison is apt. All this worm needs is a big amanita to sit on, and a hookah. Why didn't I arrange that?

People have been sending me newspaper clippings about people finding hickory horned devils. I love that. I think it reflects a growing awareness of caterpillars and just how cool they are. Would that have made the newspaper ten years ago? Doubting it. 

30 August--the dorsal zone is turning pale turquoise. This fifth instar is really a gas, with the psychedelic colors coming in. 

And here is where the Devil name comes from--the Ray-Bans on the dorsal surface of its thorax. The caterpillar has to be kind of annoyed to expose them. When it's feeling threatened, the caterpillar tucks its head against its underside, stretching the thorax to display the black "eyes." I love this look so much.

Just the best smile, don't you think? Or some say it's a Dali mustache. To me it looks like a devil with an orange crown, slightly askew. 

The caterpillar is so used to me I have a hard time getting it to expose the black spots I love to photograph. This is what the Ray-Ban's look like, closed up. I'm trying to get the bug to bow its head but nothing doing. Look how pale the dorsum, or back, of the animal is in this photo. Stay tuned for the reason.

Some mega-frass from the fifth instar devil. I open the sleeve and shake it to the ground daily to keep things clean in there. They look enough like grenades that I'm worried they'll blow up. The frass reflects the shape of the gut. That's a lot of absorptive surface!

Countershading is a fascinating natural phenomenon, and it is employed  by invertebrates and ungulates, fish and birds, to name a few. Check out the elegant countershading on these impala kids I photographed grooming each other in the Kruger of South Africa. Just where the belly starts to turn under and would be thrown into shadow in strong light, the local color of the animal lightens. And it goes to pure white on the underbelly. The net effect is that the animal's form loses its apparent shape and is flattened out, making the impala harder to see at a distance. They melt into the grass. 

This is called countershading, because the paler local color of the belly counteracts natural shadows. 

So when you've got a large, tasty caterpillar that habitually hangs upside down under twigs, the countershading is applied backward! With the HHD, its underside is darker than its dorsum, or top side. 

So it's hard to discern the creature as a rounded form--it dissolves into a patchwork of patterns, flattens out, and is really hard to see. The pale chevrons further break up its form. Perfect camouflage!

This is the sleeve. The caterpillar is about a third of the way down. Its camouflage is terrific. Sometimes I spent many minutes looking for it before I could see it. I knew it couldn't get out of the sleeve with the rope tightly wrapped at both ends, but I still sometimes concluded it had escaped before I finally saw it.

The pale chevrons on its flanks perfectly mimic the sun striking leaf edges, as you can see in this photo.

They and the countershading of the pale dorsum and dark underside make it simply disappear. Click on the photo to enlarge it for a better look--I'm going to bet you have a really hard time finding it in the small form.

And then there's the fascination of watching it demolish persimmon leaves. 

31 August,  7:22 pm . Enjoy your meal! 

More Prairie Birds, and an Auction

There’s a dry, insect-like bzzz bzzz bzzz that echoes in the silverbush and sage. It comes from the clay-colored sparrow, a bird I tried to photograph in Wisconsin with blurry results. This little bird was a lot more cooperative, whiling away the minutes on a barbed-wire fence. Such a pallid, pretty little thing, with stripes within stripes on its crown.Though there’s much talk about distinguishing it from a chipping sparrow in the field guides, there’s no mistaking the bird once you’ve come to know it. When I ran across one in a flock of spring chippies in Oak Hill, West Virginia two years ago, I called it without hesitation. It’s like the pale gray ghost of a chipping sparrow.

Here’s one of the real prairie gems—the black tern. Although it does eat small fish that it catches in the larger lakes and potholes, the black tern takes most of its food in insects. Imagine, that gorgeous streamlined tern body and wings employed to catch insects. We happened upon a colony of black terns that were just re-laying their eggs after having been flooded out. They were in a bit of disarray, milling about. Only two pairs that we could see were on eggs. We set up the scope on a nest and watched as the male and female politely exchanged incubation duties every ten minutes or so.
Oh, they are gorgeous, these terns in negative, pewter, smoke and coal. Rare is the bird whose underside is black, darker than its top. Why would a black tern not need countershading? All the other terns I can think of have darker mantles than bellies. (Countershading is what happens when an animal with a dark top and lighter belly is viewed at a distance, and kind of flattens out and fades into the background. It's thought to be protective coloration, helping animals avoid detection.) Black terns turn that formula on its head. I don't know why, but I'll think about it.

I did some sketches, and Bill wheedled until I agreed to do a painting, to be auctioned off the same evening for the benefit of the festival. The only problem? I didn’t have my watercolors with me. (We'll overlook, for the moment, that key phrase, "to be auctioned off the same evening."It was about 2:30, and the painting and I had to be ready at 5:30. Oh, and I had to give the keynote too.) Our friend Ann Hoffert came up with some watercolor pencils, which are supposed to create a watercolor-oid wash when you run clear water over the colored pencil-like marks they make. I decided to give it a shot, though I had never held one in my hand and was deeply suspicious, as many old artists are, of new-fangled things. When we got home, I had about three hours to prepare for my keynote that evening, get clean, and create an original work of art worthy of auction. Eek. “Painting” with watercolor pencils when you’re used to the drip and flow of washes is…well, let’s just say that I told the kids to leave the kitchen because they shouldn’t be hearing what was being muttered and occasionally blurted as I struggled to make something worth being held up in front of a festival crowd. Bombs were dropped.

Immediately upon bringing the piece to fruition, I tore apart my keynote address and inserted a bunch of North Dakota bird photos. Having your talks on a laptop is both a blessing and a curse. Nobody in their right mind would tear apart a slideshow right before giving it, trying to tailor it with still-wet photos from the specific area, nay, the very afternoon, of the talk. We computer-lovin' people glory in doing stupid things like that, just because we can. It's part of what makes us such a delight to be around, such surpassingly bad company. We stare and tap at our little silver boxes, mutter and hiss, and get way too involved with them.

I did not take a picture of the black tern creation as I sped out the door, trailing still-smoking laptop, artwork, colored pencils, hairbrush, lip gloss and hastily bathed and dressed kids. Despite my bad artistic karma, it came out just fine.

And went for a tidy sum at auction, for the benefit of Birding Drives Dakota. Picture Gomer Pyle, saying, “Gaa-aaw-leeeee.” Paul B., you rock. Birdchick, thanks for sparking the bidding. I don’t know if it was altruism, mercy, or partial blindness, but I am grateful. Maybe it helped that Bill was the auctioneer, sweet Phoebe was taking it around, showing it to the audience, and Liam was doing impromptu fancy-footwork dances in an attempt to whip the placid crowd into a bidding frenzy.

I resolved at the moment Bill's imaginary gavel fell at the auction never to travel anywhere without my paints and some decent brushes and paper. You’d think I’d know that by now. Durn camera. It’s too easy and fun to take pictures. Harder to make them. I spent part of this afternoon squeezing paint into tiny pans in my travel kit, and packing up a few brushes. Should the Muse or my husband, Thumper, call upon me to paint something on our next trip, at least I won't be teaching the kids new combinations of familiar old words.