Nature in Fragments: Vixen Screaming, Butt Rot Weeping and A Winter Centipede Mystery

Greetings, readers. It is I, A Maryland Naturalist, writing to you from the Information Technology Center of the AMN compound deep in the heart of Maryland. Today we offer a Whitman's Sampler from our vast archives. Please consume each chosen item completely. Do not return nibbled remainders to the blog. That behavior is beyond impolite; it leaves an unwholesome and sticky mess for those who visit after you. Be considerate.

The Vixen's Scream

There are a couple red foxes living near us, and it's always a treat to see them. They usually seem to be in a hurry to get somewhere, but it's hard to know what's going in those little red heads. Our house is built on a slope that descends to a stream. We have a great view of the woods on the opposite bank and the animals that traverse it. One day I saw a small herd of deer running through the woods paralleling the stream and a fox on our side keeping pace with them. The fox seemed to be having a great time. I wonder, did he think he was in a race? Was he lonely and imagining he was part of the herd? Did he have delusions of predatory grandeur? Mysterious creatures.

This beautiful fox was visiting our bird feeder, more for the seed than for the birds it seems. Janet, m'lady, saw him and watched him from the deck that overlooks the feeder. He looked up and she captured this photo. The fox was not overly concerned by her presence and continued his seed eating.

We hear foxes more than we see them. They make a variety of noises ... barks, howls and screams... usually at night. The sounds are rather high pitched and could be pretty eerie if you didn't know what they were. The vocalization we hear most often is called the vixen's scream. It seems to be a general purpose social call used frequently by vixens during the mating season but by both sexes for territorial or social encounters all year. One fox seemed particularly head up about something on the evening of November 24, so I recorded it. Click on the image of the trees to hear it.

Click here to listen to the vixen's scream.

Yet Another Case of Weeping Butt Rot

The polypores are a large group of basidiomycete fungi that almost always grow on living or newly dead wood. They include many of the fungi that produce shelves, brackets and conks. The name polypore refers to the numerous perforations on the fruiting body.

Upper left: Various stages of conks of Inonotus dryadeus, the Oak Butt Rot Fungus, Weeping Conk or Weeping Polypore. Upper right and lower: A young conk "weeping" a viscous amber fluid.

I mentioned the butt rot fungus, Inonotus dryadeus, in an earlier post (Pick Your Poison, 8/31/17), noting that the appearance of conks around a tree indicates that the structural integrity of the tree is probably compromised and that it may be prone to tipping over in high winds or during excessive administrative bloviation. I couldn't find a young conk for my first post, so didn't illustrate why it's called the weeping polypore. However, I later found one on the University of Maryland campus (see pictures above).  Note the numerous pores with viscous amber fluid oozing from them. I haven't found an explanation for the weeping, although it could be experiencing remorse for killing a beautiful old tree. Actually, I suspect this is the fungal version of crocodile tears.

The conks on the upper left are of different ages. The very dark ones are old and weathered and just don't understand the young whipper snappers, who are constantly whining about something or other. Snow flakes! The young ones think that the old ones are dried up and useless. Turns out that the young ones are wrong about the old ones. I recently ran across a research paper in ACS Biomaterials Science & Engineering in which the author shows that the old, dark, dried-up conk of I. dryadeus is remarkably good at pulling petroleum, certain insecticides and other pollutants from water ... like a selective sponge. This ability is apparently related to both the physical structure and chemical composition of the conk. Once the fungus is saturated, it can be dried out and burned. So, it's possible that butt rot conks could be used in sopping up oil spills. You just never know.

A Winter Centipede Mystery

No sane entomologist would look for bugs in the depths of winter. This is where I have an advantage. During a March about a decade ago, I was knocking around in a woodlot in northern Montgomery County looking for snow scorpionflies. They were there a few weeks before, but I was having no luck this time, probably too late in the season. So, on a lark, I decided to turn some logs. Upon rolling one particularly rotten one, I glimpsed several large, red centipedes escaping at high speed into the surrounding frost-coated leaf litter. This was remarkable for a couple reasons. Centipedes aren't generally known for their winter high jinks and, even at a pleasant temperature, they don't tend to hang out in groups. I guessed that this was probably an undocumented behavior of Scolopocryptops sexspinosus, a rather large (up to 8 cm or 3 inches) orange-red woodland centipede that's found in much of the eastern and central U.S. during late summer and fall. Still, something seemed "off". They just didn't seem right... not the right time of year, not orange enough, not sure.

Scolopocryptops sexspinosus collected in October 2017 from Patuxent River State Park in Montgomery County.

Later I learned of a related centipede, Scolopocryptops peregrinator, another Maryland native. It's been collected only a few times, but the known specimens were found in late fall and early spring. Its existence wasn't officially recognized by science until the early 1950s from populations near Charlottesville, Virginia and Woodside, Maryland. Could this be what I saw running around in the cold?

This explanation seems unlikely at first blush. Scolopocryptops peregrinator is described as being about half the length of S. sexspinosus and yellow rather than orange-red. A couple weeks ago, I found a S. peregrinator in my backyard under a log I had used as a chopping block and several a week later. They all match the technical description. However, my myriapodological colleague Dr. Rowland Shelley has surmised that this centipede may be active during the winter, when biologists tend to stay indoors, and so they are rarely collected rather than being truly rare. Anyway, given that S. peregrinator is a little yellow fellow, it stilled seemed likely that the big red centipedes I saw 10 years ago were S. sexspinosus.

A specimen of Scolopocryptops peregrinator collected in early December 2017. This is probably the first photo of a live specimen. Thanks to Anthony Nearman for taking the picture as I attempted to wrangle the animal into a photogenic position on the back of my extremely dry hand. Centipedes don't like to have their pictures taken.

Lately, the plot has thickened. I was looking through a collection of centipedes and other critters caught in a series of year-round pitfall traps from the infamous Leakin Park of Baltimore. The preservation was not great (colors were bleached out), but the samples contain S. sexspinosus as well as a different and equally large species that looks like a giant S. peregrinator. So, is this a new species or, perhaps, a population of giants? My best guess at the moment is that the known specimens of S. peregrinator are actually juveniles. If they turn from yellow to red as they mature, this could explain my observation a decade ago and the existence of big "unknown" centipedes in Baltimore. It also means that the adult has never been described. [And, no, I don't think the size of the centipedes is related to unusual food sources in Leakin Park.]

To make the season a little more interesting, I've made a resolution to solve this winter centipede mystery this year. Stay tuned...