…whenever I felt emotionally overwhelmed, I would take a walk in the woods. Being in the stillness and grandeur of trees had always calmed me.
~Brenda Strong
We hiked (I suppose sauntered is a better word, really) along a short section of the Haw River with some good friends on Saturday (practicing social distancing, of course). It was a beautiful day and spring was putting on a display of varied forest greens, buzzing insects, and bird calls. I carried my 300mm telephoto (and some extension tubes), hoping to get some bird pics, but ended up using it as a long distance macro lens instead.
Spring Beauties are abundant in the woods bordering the river and small tributary (click photos to enlarge)Giant Chickweed provided a delicate display in scattered locations along the trail.
The start of the trail meanders through a tangle of invasive species for a few hundred feet before opening up into a beautiful forest dotted with spring wildflowers. Spring Beauties and Giant Chickweed were abundant and the bright greens of new tree leaves painted a hopeful picture in these challenging times. We saw numerous butterflies (Eastern Tiger Swallowtail, Falcate Orange-tip, Cloudless Sulphur, Eastern Comma, some Duskywings) and heard (well, at least Melissa and Deb heard) a variety of birds, including many spring migrants (Northern Parula, Yellow-throated Warbler, Blue-gray Gnatcatcher, Louisiana Waterthrush).
At the edge of the creek, someone had moved a rock, revealing a cicada nymph’s chamber.
But, on any saunter, we usually notice a lot of the small things, the things that blend into the background. I’ve never really been a fast hiker, and now, with some knee issues, my pace is interrupted with occasional sitting on a trail side rock or log. This gives me plenty of time to notice and appreciate the details of the woods.
A Carolina Anole in its early spring brown suit.Your identification quiz for the day – which species is this?
Of course, sometimes I miss that which is right next to me. Melissa spotted this toad next to a spot where I was sitting. It remained perfectly still and allowed a few profile portraits. We discussed our opinions as to which species this might be (American and Fowler’s Toads are the common species in these parts) but they occasionally hybridize, making identification difficult. What do you think, and why? See this link and this one for some ID tips.
I have not seen many of these beetles that are bright blue instead of the usual metallic green.
As we departed, Deb spotted a shiny beetle in a sunny spot on the trail. When she called out, I assumed it would be a Six-spotted Tiger Beetle, a common species in our area in that type of setting. They are usually brilliant metallic green with a few white spots on the dorsal surface. But this beetle was a bright blue! But, looking online at a couple of resources, I think it is just a color variant of that species. It does have a couple of faint white spots on its back and there are examples of a blue coloration in some individuals of this species. Nature is nothing if not beautiful, and variable.
…it places its nest at a great height, sometimes fifty feet, attaching it to the twigs of a forked branch. Here the nest is small, thin but compact, composed of the slender stems of dried grasses mixed with coarse fibrous roots and the exuviae of caterpillars or other insects, and lined with the hair of the deer, moose, racoon, or other animals, delicate fibrous roots, wool, and feathers.
~John James Audubon
Audubon called this little bird the Pine-creeping Wood Warbler because of its preference for pine trees and its feeding habits – creeping along the branches and trunks searching for insects. It is the common winter warbler in our woods and readily comes to our suet feeders, often in group of three or four at a time (I have seen as many as seven at once waiting to get to the suet cage). Now that is nesting season, they are less frequent visitors. Instead, we are hearing the male’s trill throughout the day as he defends territory. According to research online, surprisingly little is known of the nesting behavior of this common warbler, probably because of its propensity to nest high (30 – 75 ft) out on the branches of pine trees.
But this week, a female has been visiting a patch in our vegetable garden just outside our kitchen door. I saw her on three occasions, gathering nesting material in the same spot. She intently picked through the straw, leaves, and old stems in about a one square foot spot, filled her beak, and then flew off. We watched as she made a couple of stops (typical behavior as the female heads toward her nest site so as to not give away where it is located) and then disappeared across the road to a stand of tall pines about a hundred yards away. On one of her visits, I slowly cracked open the kitchen door, stood on my tip toes to get over the edge of the side porch, pointed the camera down and took a few images as she searched.
Pine warbler gathering nesting material (click photo to enlarge)
There were a lot of interesting guesses and a couple of what I believe to be correct answers. I will preface this post with the disclaimer that I am certainly no expert on fungi (or anything else, for that matter) , but here is what I think our mystery photo is…
I thought it was a stinkhorn of some sort when Beth sent me the photo, but this is one I have never seen. This unusual species is native to Australia and some tropical islands but has been introduced to other parts of the world, most likely through in garden or soil products. In the U.S., it is found primarily in Hawaii and a few southeastern states.
It feeds on decaying organic matter and is usually found growing in yards or compost. I think the diagnostic feature for me is the bifurcate appendages – the split ends on the arms of the “starfish”. Some other stinkhorns just have single extensions at the tips. Check this link for more information on this bizarre species. As always, if someone has other suggestions on the identity of this life form, please drop me a comment. Thanks for participating and thanks again, to Beth, for sharing her yard alien with us.
I think the surest sign that there is intelligent life out there in the universe is that none of it has tried to contact us.
~Bill Watterson
Today’s mystery comes to us courtesy of Beth Howard, a friend and teacher extraordinaire in the Wilmington area. She found this in her yard and sent me a pic hoping I could help her figure out what it is and whether she needed to sell her house. In her message she asked – “What the heck is this? Is it some kind of alien life form or a carnivorous plant? That is a tunnel down through it.”
So, what do you think, and why? I’ll give you one clue…it smells a bit bad.
Alien life form or…? (click photo to enlarge) (photo by Beth Howard)
Melissa and I are happy to try to help solve your natural history mysteries (especially if you will allow me to post about it in this blog), so feel free to send me pictures of your alien life forms to roadsendnaturalist@gmail,com.
We had a few good observations and comments on our mystery post from yesterday. Deb noticed the silk strand in one of the images (reprinted below) which made her suspect some sort of silk-spinning critter. That pretty much limits what type of animal since the only two groups of terrestrial critters I know that can spin silk are spiders and caterpillars. Of course, it could also be that a spider or caterpillar just happened to go by this spot before I took the photo.
The single strand of silk in yesterday’s pic is one possible clue (click photos to enlarge)
The other clue I intended for you to see was the pic with the tiny hole in the emerging cherry leaf (see below). This indicates something has been feeding on the emerging leaf bud, again, hinting at the possibility of a caterpillar or some other vegetarian insect.
Notice the tiny hole chewed in the leaf.
As I mentioned in my last post, I have seen these critters in previous springs. I observed them slowly moving on the cherry twigs with a head and some legs protruding out the end. As I recall, I assumed it was a caterpillar based on what I could see, and then I looked online for caterpillars in swirled casings. I found images of what I now believe is a type of Pistol Casebearer Moth larvae, Coleophora sp. Below are a couple of closer images of these interesting larval cases.
Two of the mystery critters on a wild cherry twig.A close-up of a Pistol Casebearer Moth larval case (Coleophora sp.).
There are hundreds of species of Coleophora moths in the U.S. and several are called Pistol Casebearers due to the resemblance of the spiral-shaped larval case to old-time pistols. Based on my web search, this one could be Colephora atromarginata, because of the host plant (cherry) and the shape of the case. But, according to the online expert, it would take dissection of the gentalia of the adult moth to be sure (oh well…). Caterpillars of this group construct cases of silk, plant material, and frass (caterpillar poop). I think the small brown clumps you can see on the outside of the case are frass pellets. The silk is hardened by an unknown secretion (giving it the black color) and is enlarged as the larva grows (giving the case that segmented appearance). The caterpillars never leave their case and carry it with them as the crawl around on the host plant (much like a snail). When ready to pupate, they use a heavy pad of silk to attach their case to a substrate. They then turn around inside the case and eventually emerge out the back end of the case into a tiny moth. If this is the species I think it is, it overwinters as a caterpillar inside these cases, which explains why they are already this large just as their host plant leaves are emerging.
For a great video of a casebearer larva moving about, check out the incredible work of Sam Jaffe at The Caterpillar Lab. Sam is doing an amazing job of helping people see the magic all around us in the world of caterpillars.
I hope you enjoyed this mystery and we will have another challenge tomorrow.
He who finds a thought that lets us penetrate even a little deeper into the eternal mystery of nature has been granted great peace.
~Albert Einstein
Melissa and I have been talking about how we can help students and teachers during this time of online learning so I want to try to do some different things with the blog for a little while and see if it helps. Please comment if you find this useful or if you have other suggestions. Our goal is to provide content about nature that can be found in our area in backyards, greenways, parks, and other natural areas, and that can be used as learning experiences by people of all ages. So, here goes…
Mystery item found on wild cherry tree (click photo to enlarge)
While we were out observing the Eastern tent caterpillars the other day, I noticed some tiny blobs on the emerging leaves and adjacent twigs of the wild cherry saplings in our yard. They are strange-looking little things just a few millimeters across (one would fit on top of a pencil eraser). They are dark and curved into a somewhat coil-like shape.
Look for clues in the photo.
I had an idea of what they were, but I want you to use your observation skills and see if you can come to some rough conclusions. Are they from a plant, animal, fungus, or are they even a living thing? What clues can you see in the photos that might help you decide? What evidence do you have that supports your ideas?
A last look…look for clues in the photos.
If you have cherry trees in your yard, go out and see if you can find any of these little blobs. I’ll also post this on social media so more people can answer. I’ll post more information and an answer tomorrow. If you already know, please wait until tomorrow to comment.
That quote is in reference to one of my favorite native trees, the Eastern Redbud, Cercis canadensis. And right now, they are at their peak in our woods, casting sprays of pink blossoms in the understory.
Redbud trees from our back deck (click photo to enlarge)
We have quite a few of these dazzling springtime trees around our house, but relatively few (and certainly no young trees) outside the deer fence as the deer have browsed the young ones for years, leaving only older trees along the roads and scattered elsewhere in the woods. With so much more time at home now, I have been watching all the comings and goings in the trees near our deck. Unfortunately, I did not get out the camera (was busy doing some much needed yard and garden work) on the few recent sunny days when the trees were abuzz with all sorts of bees, flies, and a few early butterflies. It really made me appreciate how important these abundant flowers are as an early nectar source for many of our pollinators.
Male Pine Warbler adorning a flowering branch with some bright colors of his own.Dark-eyed Juncos are still abundant but will soon migrate to their nesting grounds farther north and to higher elevations.
Several redbud branches are close to the suet cage mounted on my deck and serve as a staging ground for birds approaching the feeder. One day last week, I sat on the deck and watched the parade of species as they waited their turn. Most managed to land behind a tangle of branches without a clear chance for a photo, but a couple of notable species shared something I did not know about birds and this tree…
Dark-eyed Junco nibbling on a redbud blossom.
I watched as a few juncos and a male and female cardinal nibbled on many of the flowers. A few times, it almost looked as if the birds were just squeezing the flower, but I also saw them pull off a flower and eat it a few times in the hour or so that I watched.
Female cardinal puling at a flower.She chewed the blossom and then dropped part of it.
Many of you may know (or may have seen Melissa’s FB post about it) that redbud flowers are actually quite tasty as a treat alone or as part of a salad (or other types of foods). So it should come as no surprise that other critters may find them suitable as a food source. I have often wondered about the use of the incredibly abundant seed pods by birds and other wildlife, but have never seen anything actually eating the seeds.
Our yard salad prepared with chickweed, redbud blossoms, and dandelion parts (photo by Melissa Dowland).
After watching the birds squeeze some of the flowers, I tried a couple to see if there was abundant nectar, but could not really tell anything definitive, other than the flower itself is tasty. The other thing I noticed when I looked closely was how the tiny irregular flowers look a lot like excited, big-nosed dogs with large ears. Maybe its just the self-isolation talking….
While out in the yard looking at the tent caterpillars the other day, Melissa turned around and saw an interesting pattern on the trunk of a small tree. The pattern and details of the egg tops told us it was the egg mass of a Wheelbug, Arilus cristatus. Wheelbugs (and many other members of this family of insects known as assassin bugs) typically lay a patch of eggs covered with a resinous substance that hardens as it dries. This is a fairly large egg mass, measuring about 2 inches from top to bottom. If you are bored inside today, perhaps you can guess how many eggs are here, and then count them…you may be surprised.
Egg mass of a Wheelbug attached to a small tree (click photos to enlarge)
A closer view shows the typical fringe-like border around each egg top. I’m not sure what the function is, but I am guessing it could be to increase surface area for oxygen absorption.
Close-up of the egg mass shows the fringe along the top of each egg.
A side view shows the eggs are somewhat bottle-shaped and tightly stacked together. One reference described the eggs as looking like “brown bottles with fancy stoppers”.
Side view of eggs…the tiny dots are pollen grains.
These should hatch sometime later this spring and a horde of tiny reddish-orange and black (at first) robotic insects will be unleashed. I am guessing they may prey on one another as well, so their numbers will be greatly reduced before they reach adulthood in late summer (there is one generation per year). Once they are at that stage (over an inch long), they are formidable predators of many types of insects from caterpillars to bees. They are important predators of some pest species like the introduced and invasive Brown Marmorated Stink Bug, and some hairy caterpillars (like tent caterpillars) that are avoided by many birds. With their distinctive gear-like crest and large size, they are fascinating to observe, but handle them cautiously (or better yet, not at all), as they can inflict a painful bite with that long, needle-like beak.
An adult Wheelbug with its namesake armament and strong, piercing-sucking mouth part.
“Follow, follow, follow, follow, follow the yellow brick road… We’re off to see the wizard, the wonderful Wizard of Oz… because, because, because, because, because, because of the wonderful things he does…”
~The Munchkins of Oz
In this particular case, the road is not so much yellow and brick as white and silky… but these little critters certainly do some wonderful things…
Eastern tent caterpillars on a cherry tree branch
Hey, Roads End Naturalist readers, it’s Melissa here. With a little extra time on my hands I’ve been thinking a lot about ways to help teachers who are trying to teach virtually and parents who are now homeschooling to use the natural world as a teaching tool in this time of social distancing. So yesterday, I went out to document one of the most ubiquitous and friendly critters at this time of year – eastern tent caterpillars – as an idea for a subject to explore in your backyards or local parks (while staying 6′ from other people, please!).
Eastern tent caterpillars are the furry little guys who come out just as tree buds break in early spring and construct a silken web in the crotches of wild cherry tree branches. They’ve spent the winter as tiny larvae housed inside of an egg case that looks like a shiny, swollen growth on the tree branch. Our eastern tent caterpillars have been out and about for a little more than a week now, if memory serves me right. (Let’s see, I started to notice them in the branches before I stopped going to work, and that was a week ago Friday.) Most of them now are about 3/4″ long and starting to show some of the patterning that they’ll have later in life. And their tent homes range from about 4″ to 6″ across at this point.
Eastern tent caterpillar nest in between branches of a cherry tree with one caterpillar out on the surface. The dark spots inside the nest are frass (caterpillar poop).
Yesterday afternoon I got to observe a few of their really interesting behaviors when I went out for a look with the camera. I was very excited to note the silvery trails of silk running along most of the branches on the tree. As the young caterpillars go off to feed, and as they return, they leave a silken trail that is laced with chemical scents that guide the other caterpillars between the nest and leaves that they are feeding on. Over time, the silken “roads” become quite substantial. Apparently, a lot of research has been done on this behavior, and studies have shown that they are able to change the scent of the trail depending on the quality of food resources at its end – when a caterpillar comes back having fed successfully on a tasty branch, the next round of feeders will follow its trail back to the same spot.
I was even more excited when I saw a caterpillar follow a silk trail down one branch and back up another. Eventually, the caterpillar turned around and marched back to its nest – perhaps because at the end of the trial in the other direction was a different nest? It moved surprisingly quickly, so I had to anticipate its position along the branch to get a shot.
Tent caterpillar following a silken trail down a cherry tree branch.
A little later, after borrowing Mike’s fancy new camera with its twin light flash unit to try to better capture this phenomenon, I went out to a different, lower-down nest to try to get some closer images. The scene was totally different from earlier in the day! If you read this blog often, you probably know a little about caterpillars, as it’s a favorite topic in our household. But as a refresher, caterpillars shed their skin, usually five times (six for eastern tent caterpillars), to accommodate their dramatically increasing size as they grow. An analogy Mike once shared with me is that if a human baby grew as much as a caterpillar, it would end up the size of a blue whale! No one wants to live in a crowded house (especially when you’re not allowed to leave it… ah, pandemic humor…), so eastern tent caterpillars add additional layers of silk over time to increase the size of their nest.
The caterpillars have multiple “stories” to their house and can move between the layers of silk. You can see caterpillars within different levels of the nest in this image, as well a few out on the surface.
And since they don’t have HVAC systems, they also use their nests for thermoregulation. One study I read said temperatures were typically 4 degrees C higher in the nest than outside of it (that 7.2 degrees F if you’re like me and need the conversion)! Of course, on a warm day like Friday, that might not be a good thing, and the caterpillars were congregated on the shady side of the nest when I went back out to see them. I’m not sure if this was because it was cooler, or if this was their typical nest-expansion aggregation behavior.
I’m not sure if these caterpillars were expanding the nest or thermoregulating by hanging out in the shade, or maybe both. But it sure was cool to see. They moved around a good bit while on the outside of the nest.
These caterpillars really are fascinating. Numerous references (like this one and this one as well as a favorite classic field guide, Observing Insect Lives by Donald Stokes) note that they typically have 3-4 periods of feeding during the day. Apparently, the pattern is that they aggregate outside the nest and add layers of silk to expand it, then go off and feed. Sure enough, a little later (once I’d solicited Mike’s help to bend the tree down so I could get a better look at the nest), lines of caterpillars were marching along their silken roads back from the outer tree branches, I assume after having fed on the tasty, tender cherry leaves. This was the coolest moment yet – seeing the little caterpillars nose to tail marching down the branch and back home!
These caterpillars were marching down the branch toward their nest. You can see the silken “road” if you look closely under their bodies. Take another look at the first image in this post for another example.
They all marched right into the nest to hang out until their next bout of feeding.
One corner of the nest is at the right side of the image. The caterpillars entered through a hole where it meets the branch.
Here’s a few other interesting tidbits that I gleaned in researching this subject…
If there’s more than one nest in a tree, eventually the trails from caterpillars in each nest will run into each other. Apparently, the caterpillars will share nests. Friendly little guys!
Caterpillars in the same nest may be at different stages of development. It seems that development rate is linked to temperature, with warm temperatures being correlated with faster development.
Eating eastern tent caterpillars can cause abortion in horses! In 2001, more than 3000 mares aborted fetuses as a result of eastern tent caterpillar ingestion. My initial guess was that the concentration of cyanide, which is naturally found in cherry trees, by caterpillar feeding was perhaps the cause of the issue. However, it turns out that the hairs on the caterpillar are able to penetrate tissues inside the horse, and those hairs carry bacteria which, when they reach the uterus, can infect the horse and/or fetus and cause abortion. Fascinating!
So, here’s my challenge to you. Get out in nature (with proper social distancing), and see if you can observe some of these fascinating behaviors of eastern tent caterpillars!
If you’re looking for ideas for teaching kids at home, maybe challenge them to observe and document behavior over time. Here’s some questions and ideas to consider:
Can you document which times of day the caterpillars like to go out and feed? How does weather affect their behavior? What happens when they’ve eaten all the leaves on a branch?
Use a thermometer to measure the temperature on different sides of the nest – where is is warmer or cooler?
Use a compass to note the direction nests are facing – do they tend to be built at a certain orientation? Are the silk trails typically on a side of the tree facing in a particular direction, or is it more random than that?
How many caterpillars can you count in a single nest?
Using your observations, write a story or poem describing what it’s like to be a tent caterpillar, hanging out in a tiny silk nest with hundreds of your brothers and sisters… maybe not too dissimilar from your life right now? If anyone does this activity, feel free to post it as a comment on the blog – Mike and I would love to read some of your writing!
And if you really want to get into it, this book I found online has a whole bunch of experiment ideas using tent caterpillars – it’s chapter 17. I can’t find a way to link to the specific page, or even a page number to give you, but I found it by searching “eastern tent caterpillars” within the text.
I’d love to hear if any of the ideas are useful, or if you observe any interesting behaviors in your tent caterpillars. Please share in the comments on the blog or tag Mike and I on social media!
My scientific life has been spent describing the interactions that occur when butterflies meet and trying to understand what is going on and why…I persist in following butterflies with stopwatch and notepad.
~Ronald L. Rutowski, North American Butterfly Association
Yesterday’s sunshine (why can’t we seem to have at least two days in a row of that here lately?) brought out the invertebrates in the yard. I looked out the window at one point and saw a fluttering small white butterfly checking out the Hairy Bittercress weeds in the front yard. It was a female Falcate Orangetip (Anthocharis midea), and those weeds, members of the mustard family, are one of her host plants. These tiny butterflies are one of the sure signs of spring as they fly for only a couple of weeks early each year, looking for members of the mustard family on which to lay their eggs.
The distinctive developing seed pods of the common yard weed, Hairy Bittercress, Cardamine hirsuta (click photos to enlarge)
I grabbed my camera and by the time I got outside I saw another butterfly, this one with orange wing tips (a male Falcate Orangetip), pursuing the female. What followed was 3 minutes of intense butterfly behavior (and burst mode shooting on my part). The male’s flight pattern was rapid and erratic and he would dive in and briefly flutter near her before darting off and circling back.
Male Falcate Orangetip (with orange wing tips) fluttering near female perched on one of her host plants.The female maintained an abdomen up position the entire time.It seems as though the male’s efforts were unsuccessful as he eventually flew off and she continued patrolling the yard for bittercress.
I have seen this abdomen up behavior before when watching Falcate Orangetips. I have always assumed it was the response of a female that is not interested in the male’s attention. But, some research on a closely related European species shows that both receptive virgin females and non-receptive, previously mated females, show this raised abdomen behavior when a courting male comes a calling. The difference may lie in what chemical compounds the female is releasing when the male gets close. In one case, it may be an attractant pheromone. In the already mated females, it is believed to be a repellent.
A single tiny egg on the flower of the host plant.
After the male departed, I tried following the female around the yard to see if she was going to lay an egg, but she eventually wandered off through the woods. I went back to the original plant I had seen her land on and began to search it for an egg. I finally found one – a tiny sculpted egg, laid at the base of a flower, just where the online references had said it would be. She supposedly deposits a pheromone on the egg that keeps other females from laying an egg on that same plant as the larvae are known to be cannibalistic. Now I want to try keep track of it as the larvae (and especially the thorn-like chrysalis) are extremely hard to find. The things you can do in self-isolation…
For more on the behavior of butterflies and their mating habits, check out this article, When Butterflies Meet, from the North American Butterfly Association.
Roads End Naturalist 