Spiny Oak Slug Caterpillar — Look But Don’t Touch!

spinyoakslugcaterpillarb06-04-15While working on the front yard, we ran across this odd creature at the base of a rogue Hackberry seedling. It seemed fairly obvious that it was some sort of caterpillar, until we saw it move. Then it was like… WHOA. Instead of seeing it move along like a regular caterpillar with its legs and prolegs (though apparently a caterpillar actually moves by its gut), what was visible on this caterpillar was a wavelike motion as it traveled. The closest creature I could compare it to, barring that of something from the ocean, was a slug. Turns out that I was right on the money… its common name is actually “slug caterpillar,” or in this case a Spiny Oak Slug Caterpillar. I’m fairly confident about the ID, except that there seems to be a wide variation in color for these little guys. If I were to guess, their coloration might have something to do with what actually tree they are feeding on, or what instar they might be in, but again, just a guess.

To share this amazing undulating movement, we took a video, seen below. We used a macro to get in close to see the waves, hence the occasional moments when the caterpillar goes out of focus. But the gist of the movement is there.

Since this is the first time I’ve ever run across this type of caterpillar, I don’t have a lot of details about it. It will turn into a moth, and my instincts NOT to touch it were spot on. Like other slug caterpillars in the family, it has a painful sting, though this one is milder than some of its cousins. Also, its thoracic legs are reduced, contributing to those rolling waves being such a predominant feature.

spinyoakslugcaterpillar06-04-15Among its host plants, the Spiny Oak Slug Caterpillar eats the leaves of Oak (no big surprise there), Hackberry (also no surprise), Ash, Cherry, Willow, and many other trees. Though we yanked out the Hackberry seedling — it was growing right in the middle of a multi-trunked Yaupon — we took the caterpillar over to another Hackberry being allowed to grow.

Finding things you didn’t know existed is so fun!

Sad News… Nature Struck Us a Blow

No pictures, just an update. With a sad heart, I have to tell you that our Eastern Screech Owl family suffered a tragic blow. A bee swarm, on the hunt for a new cavity to call home, found our owl house and decided to move in. Unfortunately, our 3 young owlets were still inside, and sadly we couldn’t help them, nor could their parents. The bee colony, in typical swarm fashion, was huge. The bee rescuers who came, along with other folks we talked to, said it was very unusual for bees to move into an occupied house. But our owlets were still quite small, and my guess is the bees didn’t see them as much of a concern.

We are devastated and are mourning the loss of 3 innocent baby owls. Such a pointless death, Mother Nature. But despite our unhappiness at the bees, they now have their own “official” hive and will hopefully work hard making honey for themselves and the beekeepers who rescued them.

Since this is our second swarm in a year, one of the bee rescuers brought out a special bee box to entice the next group of bees to move in there instead of our owl box. Let’s hope it works — perhaps we can be a regular source of bees for them, and something positive will come out of this tragic situation. Mama and Papa Owl, I hope you will return next year.

Sometimes Camouflage Doesn’t Work

My last post was about camouflage, but the truth is, sometimes even the best camouflage can fail you, and you become lunch (well, in this case, a dusk-time breakfast for the baby owls inside the nest box). Here one of our screech owl parents is delivering to their owlets what appears to be a walking stick insect.


It always amazes me what incredible nocturnal hunters owls are, but especially screech owls. It’s easy to imagine larger owls hunting bigger active animals, such as rats, rabbits, and even skunks. But screech owls bring home caterpillars, worms, lizards (including diurnal ones that theoretically shouldn’t be quite as active at night but perhaps are), scorpions, centipedes, and apparently stick insects. Sure, I can still imagine some of those being reasonable prey, but caterpillars? Some of them barely move (relatively speaking) and often blend in among bark, foliage, etc.

Owls, I am impressed and quite jealous of your superior eyesight and stealth ability. I shall continue to watch you exhibit your skills for those few minutes at dusk when I can still see you before the darkness takes over and my limited nighttime vision fails me. Oh, to be an owl!

Edit: My friend Justin reminded me that this video of awesomeness exists. For your viewing pleasure, and thanks to its creators:

Now You See Me… Now You Don’t

It just so happens that at work I’ve been creating new nature activities for kids, this time the focus being how animals utilize camouflage for survival or for catching prey. I’ve been gathering pictures of camouflaged animals, which is a bit of a challenge because I have to actually locate the hidden animals first.

Today I rescued a moth trying to escape through our chicken coop window and was ecstatic to realize it was an underwing moth (so sorry to the other moth that one of the chickens got to first). Perfect camouflage photo op ahead, as long as the moth didn’t fly away too fast!


Worn out from the window experience, the moth was happy to take a rest against the bark of an oak tree, a perfect spot to blend in. Can you find it in the photo above? Once you’re confident you see it, click here to verify.

In the case of North American underwing moth species, they depend on oaks and other native tree species not just for protection, but to feed on during their larval stage. They earn their common name for the brightly colored wings hidden underneath the peppered ones.


That flash of color might startle a would-be predator to reconsider going for the moth in some circumstances. But it’s the patterned brown, black, and gray wings, when closed, that likely afford the moths the best protection against a woody background.

For the kids’ activity I’m working on, we’ll be playing with creating and testing our own creations, with matching coloration and patterns, against objects in both nature and the classroom. I ordered a large spider craft punch, perfect for the activity (at work we’ll also be getting bird and butterfly punches). The kids will be hand-coloring their animals according to the area in which they want their animals to hide, but at home I found some colorful magazine pictures for quick cut-outs. How quickly can you find the spiders in the following pictures? Among the following 4 pictures, there are a total of 7 spiders. I expect that you’ll be able to find them relatively easily, but consider as you do what makes them stand out or blend in. Which spiders would likely be most effective at hiding then ambushing their prey?camouflageactivity20150523 camouflageactivityB20150523 camouflageactivityC20150523 camouflageactivityD20150523

In some of our afterschool classes, we’ll also be using animal camouflage studies for biomimicry activities — students will design their own inventions that incorporate camouflage techniques to avoid detection.

Animals go to great lengths at times to avoid detection. While some are built-in through concealing and disruptive coloration, other animals will disguise themselves or exhibit other behavioral adaptations to avoid detection. Of course, these survival adaptations and strategies have evolved over long periods of time through the natural selection process. One of my local favorites is the Trashline Spider; it gathers insect carcasses in a line on its web and then hides among them.


Just think how many animals might be hidden in plain sight near you as you take a walk in nature!

Reptiles in the Garden

Last weekend I gave my last presentation of the spring, and the very next day I seized an opportunity to work in the garden for a change. It was a beautiful day, and of course in my eagerness to be outside, I forgot both hat and sunscreen, and I soon sported my first and hopefully only sunburn of the year. I wasn’t alone out there, either. Basking in the warmth of the day was this beauty, a male Texas Spiny Lizard (Sceloporus olivaceus).


He was so chubby that at first I thought it must be a female ready to lay eggs, but nope, his markings clearly indicate otherwise. It’s a little hard to see it in this image, but he has light blue stripes along the sides of his belly — females don’t have these.


He wasn’t afraid to let it all hang out, clearly. I’d like to think that if a female were nearby, he suck that chubby belly in, puff out his chest, and do a handsome pose. Clearly he should be practicing those defensive/offensive push-ups male Texas Spiny Lizards are known for (when confronted by other male Texas Spiny Lizards in their territory) — perhaps he could get in better shape. But then again, perhaps this round belly equates to “hot” in the lizard world.


On the other hand, he’s limber enough to do the splits, and to stay in that pose for a while while I took pictures.


Check out the markings on his gorgeous tail.


Yes, yes, you’re a pretty handsome insectivore after all, little big guy. TXspinylizardD-hole04-26-15

My son said he saw the lizard coming out of this hole in one of our raised beds. I wonder whether the lizard was using the little tunnel as a cool haven, or whether a female might be prepping to lay eggs in there. I haven’t had a chance to inspect the spot since then to see whether the hole has been covered up or not. If it is, I suspect there might be little eggs inside.


Despite being described as an arboreal species, I have these Texas Spiny Lizards all over my garden and rarely see them on a tree. I guess they have too much to feast on in the garden area. I imagine they’d blend in much better on the bark of a tree than on the wood of my veggie beds or on the rocks around on the pond. But I’m happy they’re willing to hang out on the ground with me.

Getting back to working on the garden, I decided to tackle the weeding of a small perennial patch in the backyard, and in doing so had to move aside several bordering rocks. It’s best to move such rocks carefully — all sorts of little creatures might be sheltering under rocks to stay cool and out of the light (scorpions, centipedes, snakes, etc.), and one wouldn’t want to get a jolt of surprise or worse, pain, from reaching under a rock blindly. But under one rock, I did find a wonderful garden resident.


It was a Tantilla snake, one of the Blackhead species. Some people call them Centipede Snakes, named for their favorite food. The small snakes also eat scorpions and other invertebrates. Like their prey, they are nocturnal and favor rocks to hide underneath. They are colubrid snakes and are non-venomous.


I think this snake must have realized I’m a Snake Whisperer and completely calmed down in my hand. What a beauty. It was probably about 10-12 inches long.tantillasnakec04-26-15

Of course, as soon as I set it down, the snake scurried off for shelter, making use of its fossorial lifestyle and digging right into the earth. But we were able to get a quick picture — you can see the earthy coloration of the rest of the snake’s body.

And so I went back to weeding that garden bed. Lo and behold, under the very next rock was another snake, a much smaller one. It was a Leptotyphlops snake, or a blind snake, about 6 inches long. It looked almost silver in the sunlight but shows a pinkish undertone in the pictures.


These little burrowing, nonvenomous snakes are often confused with earthworms due to their size and coloration. Their eyes are reduced in functionality, serving only to perceive light — they aren’t truly blind, but very nearly so. They spend most of their lives underground.


The main diet of blind snakes consists of ants and termites, along with their eggs, larvae, and pupae. It is believed that the snakes can follow the pheromone trail left by the insects in order to find their colonies. Sometimes blind snakes will also eat millipedes or centipedes. Their scales are smooth and tightly overlap, helping protect the snake from the bites and stings of ants. The tail ends abruptly, mostly rounded with a small point at the very tip.


This little snake was quite a wiggler, and I used a clear bowl with some leaf litter to hold the snake for a moment while I snapped a couple of pictures. But I didn’t want to stress the little snake out — I quickly returned it to the safe haven of its rock in the garden.

I’m so glad to run across these reptiles from to time in my garden. It means my wildlife habitat is functioning well in terms of the ecosystem —  predators such as lizards and snakes are natural and very important pest control. Of course at night, they have to be careful, too — we have hungry screech owls that are even higher in the food web, and they’d love a chance to catch one of these little snakes. The lizards, being diurnal, might be safe if they have a good place to hunker down at night. Always excitement in our backyard!

Baby Squirrels Peek Out… Also, Owls!

Despite our amused annoyance that a squirrel family is squatting in our new-and-improved owl house, it’s hard not to be heart-touched by the curious and playful little babies. They’ve been growing fast and are already peeking outside and trying to figure out how to safely get out of the house.squirrelsc04-10-15squirrelsa04-11-15 They also seem to share the window a little better than last year’s owlet siblings did.squirrelsd04-10-15

I just wish they wouldn’t chew on the box!screechowl04-11-15

The latest exciting news is that we have officially confirmed that we do indeed have an owl family in the older owl box, which we had moved to a different tree last fall. Unfortunately for us, though, it’s the one without an owl camera inside, so we have no idea yet how many babies are inside. But the fact that we see Mama Owl regularly now means that the babies must be big enough that she needs a window seat. It’s going to be harder for us to view the owlets as often as in years past — this owl box is wayyyyy in the backyard. But we’ll try!

And the Owl Cam Reveals… Squirrels

For the past few years, we’ve enjoyed watching Eastern Screech Owls nest in our two owl boxes. Last summer, after we had to remove a box filled with swarming bees, we used the opportunity to build a new box complete with a camera for peeking inside. We had hoped that the owls would just move right in this spring, but unfortunately each time we checked the Owl Cam, we found no residents — until last night, that is. What we found was not feathered friends but instead furry ones. There’s a squirrel family in our owl box. Sigh.


But they are pretty darn cute. As much as we would prefer the owls, we can’t evict this little family of wiggling, curious critters. We can only hope that our owls have moved into our 2nd box in the far backyard (where there is no camera).squirrelsowlboxb03-24-15

Somehow we went from a completely empty box to a full nest — these little squirrels already have their fur and have big open eyes. Clearly it had been a couple of weeks since we checked the owl cam! There are at least 4 babies in there with Mama Squirrel — possibly 5. Last night when we discovered them, they were nursing and sleeping away. This morning, they were crawling all over Mama and reaching up toward the light.squirrelsowlboxd03-24-15

Mama was not getting any sleep, so when she’d had enough of the little ones crawling all over her, she set about to grooming each of her infants.squirrelsowlboxe03-24-15

They got drowsy right away, and Mama soon joined them for a nap.squirrelsowlboxf03-24-15

At first one little babe just refused to settle down, until it tucked itself under Mama’s tail for a cozy spot.


Here’s a view in full-color mode. And there you have it — a new family of naughty little squirrelsies to wreak havoc at local bird feeders and drive our neighborhood dogs crazy.

The Herald of Spring

This morning my dogs and I visited our favorite leash-free nature-plenty park for a bit of exercise. We enjoyed following the paths through a winter assortment of evergreens, bare-branched deciduous woody plants, and golden-to-brown spent grasses and herbaceous plants (granted, the dogs were far more interested in animal smells while I, on the other hand, forego those risky smells and instead admired the plants). But I pulled up short when I spotted this treasure among the winter scene, tiny yellow-green blooms looking like miniature fireworks among the brown branches. I knew immediately that Elbow Bush was announcing the imminent arrival of spring ahead.


Elbow Bush, or Forestiera pubescens, is a deciduous Southwestern shrub that blooms much earlier in the year (Feb-Mar) than most other plants in the region. In fact, another of its nicknames is Spring Herald. Its blooms, which open before new leaves bud out, are important nectar sources for early-emerging butterflies and other pollinators. Later on, the female plants will produce dark-blue berries that are a favorite of wildlife.


Yet another name for Forestiera pubescens is Stretchberry. But here in our area, I know this shrub best as Elbow Bush, a name earned because the plant typically branches at right angles. It has tremendous wildlife value and makes a great understory addition, but gardeners should note that it does have a thicket-forming habit. So perhaps it might serve a naturalistic landscape best.

It won’t be long, and this plant like so many others will be covered in green foliage. Also spotted in bloom today — Mexican Plum, Agarita, and one wee little bloom on a Mountain Laurel (and all three were deliciously fragrant, too — I couldn’t help but check). Spring cometh!

Seed Dispersal Fascination

Walking through the winter garden today, I wandered among patches of brown, spent perennials and annuals long gone to seed. I let the seeds linger for the sake of wintering birds in need of food and to hopefully let them spread their habit a little.

Frostweed (Verbesina virginica L.)

Frostweed (Verbesina virginica L.)

I’ve always been fascinated by seeds — shape, size, patterns, and especially dispersal methods. Plant species over all their thousands to millions of years of existence have evolved remarkable ways to disperse their seeds. After all, it’s to their advantage to send forth their seeds, not just to ensure population survival but to also not have tons of little baby plants growing up at their feet, so to speak — stealing sunlight, water, nutrients, and space from their parents.

Frostweed (Verbesina virginica L.) produces copious seeds to feed overwintering birds.

Frostweed (Verbesina virginica L.) produces copious seeds to feed overwintering birds.

Different plant species have different means of getting their seeds out into the world, of course, but generally speaking they fall into several main dispersal categories:

  • Wind (Seeds float or flutter with help of the wind)
  • Expulsion (Seeds are forcibly expelled)
  • Gravity (Seeds bounce and roll)
  • Animals (Seeds stick to, are eaten and digested by, are eaten as fruits with seeds discarded, or are stored and planted by animals. Note that humans take seed dispersal to a whole other level — sometimes with disastrous effects, such as spread of invasive plants.)
  • Water (Seeds float to a new location)

Assorted cones

Furthermore, some plants only release their seeds in response to certain triggers, such as heat from the sun, water, or drying. As another example, certain pine trees might drop their cones all over a woodland floor, but the cones will only release the actual seeds in response to a fire hot enough to burn living trees in the area. Such a trigger-dependent adaptation is called serotiny.

Wafer Ash (Ptelea trifoliata) seeds have circular "wings" to help them flutter to the ground.

Wafer Ash (Ptelea trifoliata) seeds have circular “wings” to help them flutter to the ground.

Some seeds have parachute-like adaptations, such as the classic dandelion, that let them travel long distances on the wind, while other seeds have “wings” that help them flutter down or reach several feet away. Other seed heads spill out their seeds when a strong wind tilts the stem, such as the seed cup of a poppy.

My favorite example of expulsion, or forced dispersal, is that of the bluebonnet, whose pods twist and pop open in the warm sun, sending out their pebble-like seeds out a few feet away. Unfortunately, I don’t have any pictures of this action… yet!

For water dispersal, think of seeds that float, such as those of water lilies, lotus, and the all-time classic… coconuts.


Cedar waxwings feasting on Yaupon (Ilex vomitoria) berries

In terms of animal dispersal, I can attest, having three dogs, that seeds that have hooks, spines, or barbs (such as burrs and stick tights) are very effective in getting their potential offspring spread far away from the parents. Birds can carry seeds great distances simply by eating fruits and seeds off one plant and then pooping out the seeds many feet or many miles away. And then there are squirrels and blue jays, notorious for planting acorns and other tree seeds, some of which will surely grow.


The seeds of Inland Sea Oats (Chasmanthium latifolium) present themselves in a graceful arch, until birds and wind start to disperse the seeds.


As the seedheads of Velvet-leaf Mallow (Allowissadula holosericea) mature, they open to reveal a cool radial pattern.

Gravity comes into play with many species — obviously it’s going to influence where seeds land, regardless of overall dispersal method. Never underestimate the success potential of a seed that has simply dropped and rolled to a perfect soil and light location.

seedmaterials11-15Working with kids has made the study of seed dispersal all the more fun. Want to challenge your children or students? Have them use different craft materials to design their own seeds with different methods of dispersal. Then test their dispersal success — possibly with a fan, a tub of water, a measuring tape to determine expulsion distance, or cloth or stuffed animal as “fur.” Try it yourself, too!