Naturespeak A naturalist's view of the world

November 28, 2011

Flying Fox

Filed under: Uncategorized — wykes @ 6:15 pm

Durwood Allen has always been a name on my mental list. As wildlife biology major in college I always managed to drift towards one or two of his research papers as a source of primary material. Although the wildlife biologist eventually went on to national status, he spent a good deal of field time working for the old Michigan Department of Conservation from 1935-1946. Perhaps because he earned his PhD from Michigan State University, I naturally thought he was one of the best (which he was, of course, but not for the limited reason I just mentioned). Among his many publications, perhaps the Wolves of Minong, about Timber wolves, was his best known but the one that brings me to this blog posting was Michigan Fox Squirrel Management (1943).  I know you all have this on your summer reading list but few are wiling to admit it.

Every time I try to look up something about Fox Squirrels I end up with citations referring back to this work. Because the research was done primarily in Michigan it is a great source for finding out why and how Michigan Fox squirrels do what they do. True, these squirrels pretty much do the same thing wherever they live, but they do look -and occasionally act -different when “out-state.”  Their scientific name Sciurus niger, for instance, rather than meaning “foolish brown road crosser” actually means “black tail user” (loose translation, mind you).  Midwestern Fox Squirrels are orangish brown and they only rarely come in black. Out east, however, they often are black, or have black heads with white muzzles and all sorts of unnatural coloration. They were originally named based on an “out east” specimen (by Linnaeus in 1758) and thus the reason for the black coloration reference.

While recently watching a Fox Squirrel dedicate a day’s work towards winter nest-building, my curiosity was piqued. This fellow was doggedly (squirredly?) gathering up leaves and carrying them high aloft to his nest structure.  He was one of our so-called marsh squirrels which subsist on the fringe of Cottonwood Trees surrounding the cattail marshes.  His route from ground to nest and back was a very specific one. At the base of one Cottonwood tree he would quickly gather a mouthful of leaves and scurry up the trunk on the eastern side. At a certain point he would curl around to a branch on the southern side of the trunk and perform a pair of flying leaps taking him to his nest via three separate branches. The leaps are admirable, especially given the fact that Fox Squirrels are not considered to be as agile or able as their lesser cousins the Grays (watch the movie clip here). He followed this circuitous path without variation for as long as I watched him. I can’t tell you how many times, but it was longer than a normal attention span would allow.

My Durwood Allen moment came when trying to discern the finer points of nest building behavior. Rather than make something up (an entertaining, albeit shameful option) I chose to augment my observations with real research results. My observations were clear enough. This squirrel wasted no time at his nest. He rammed the new load of leaves into a side entrance, shuffled them around a bit, and quickly emerged for another foraging trip. The ball shaped structure consisted of a combination of sticks and leaves and was located right up against the trunk of the tree. According to Allen’s work, the typical Fox Squirrel nest has a side entrance, is about 7 inches in diameter, and located 30 feet up. It looks like my squirrel read the rulebook.

Fox Squirrels – at least those individuals who survive centerlines and curbs – tend to built two nests per year. They construct loose summer nests in the outer branches and typically resort to tree cavities in the winter. Where tree cavities are at a premium in the cottonwood tree lines, our winter squirrels construct tight winter nests right up next to the trunk.

There is no correlation between the size or location of squirrel nests and the severity of upcoming winter weather. I guess you could say that crumbling winter nests are an indication that a hard winter is in progress because these structures quickly fall apart if not constantly maintained. Since dead frozen squirrels can’t maintain their nests properly, their bad nests are some measure of bad winters (not a forecast, but more like an Indian weather rock prediction).  Looking at the size of the squirrels, as opposed to the size of their nests, is probably a better way to judge their individual survival chances. It goes without saying that you must remove the road factor from this equation.

Watching my average-looking squirrel leaping through mid-air caused me to wonder how much the average Fox Squirrel weighs. Allen reveals that the average adult weight of his Fox Squirrel population was 28 oz. – or a little over a pound and a half. Any individual around this target weight should have no problem making through the winter. The heaviest one that Allen recorded weighted in at 43.5 ounces – over two and a half pounds. I doubt that portly rodent would have been able to make the nimble jumps necessary for cottonwood climbing. Such a beast would fit in nicely with the current crop of piggish Fox Squirrels that park themselves at our backyard bird feeders far from the marshes.

November 22, 2011

Two Buck Transaction

Filed under: Uncategorized — wykes @ 6:33 pm

I was contemplating doing a blog about slug racing one early morning on my way into work. While mulling the topic around my mind buds, I glanced up and noticed a White-tail buck walking across the road. His head was down and he was “on the trail” just like a bloodhound on the trail of an escaping jailbird. There is nothing quite like a buck in rut – you can tell one from a mile away just by the way they hold their heads while smelling the sweet scent of doe. I stopped to get a better view of the beast and all slug thoughts went out of my mind (and, since I am not a hunter, thoughts of leaden slugs did not replace these thoughts). Although many years in a park setting have taught me that deer are basically long-legged rats, I will always stop to look at antlered rats. When a second antlered rat… er, I mean a buck… entered the scene that morning, I sensed a bit of electricity in the air and the potential for a real honest to goodness smack down fight.

Two years ago, I was lucky enough to photograph two middle-sized bucks going at it (look up “White-tailed Rumble” and see if it’s still on U-Tube). For a moment, I thought my second chance had arrived – on a sunny photogenic morning at that.

The buck that initially caught my eye wasn’t all that impressive. It had a decent 8 point rack and the kind of looks that would have earned it the “nicest guy on campus” notation in the yearbook. In other words, it wasn’t one of those mutant body-building hunk type deer, but a decent fellow with good grades.  As I mentioned, he was stalking across an open field towards a thicket edge. His head descended to the ground for a few occasional sniffs while maintaining a steady forward momentum at a consistent trot speed. He completely ignored my presence, even after I shouted out the window to get him to stop and turn around for a head shot (remember, I was armed only with a camera, so don’t let my lingo confuse you).  When he suddenly stopped in his tracks and directed an intense stare at the north end of the thicket row, I was ready for some action.

If a doe appeared, then I might be witness to the fawn manufacturing process. When another buck sauntered out, I was both relieved and ready (there is no way I was going to film deer mating). The second buck was quite large. His neck was swollen with hormonal pumping and long sessions of bush-whacking.  This animal slowed his pace upon spotting the first, but dropped his head almost immediately to “feed.”  The first buck continued to stare, but soon resumed his forward movement. He also dropped his head as if feeding.  Although their gazes were averted, the two potential rivals were obviously sizing each other up.  Animals often involve themselves in a behavior known as displacement when faced with a stressful situation. They may start to groom or tear at the grass as a way to alleviate their internal conflict. We humans do the same thing. When confronted with something uncomfortable we twirl our pencils about in our fingers, or re-direct our gaze at some fascinating spot up on the ceiling.

There was an immediate problem, however, at least on my part. It was plain to see that the second deer had very small antlers. Technically they were four-pointed (six points if you count the two nubbins at the brow) but actually more like sporks -by that I mean those flattened fork/spoons. Antlers are a status symbol among bucks. Fights do not usually occur between bucks of different antler size. The one with the bigger set automatically wins the field and that is that. My chances at seeing a rumble were rapidly vanishing.

There was still a flash of hope as the two kinda-sorta circled each other.  The one with the larger antlers was not all that impressive, while the small antlered fellow was quite beefy. I wondered if body size had anything to do with the “fight or flight” decision between contesting bucks. The large body/small antler deer (the one I am calling the second one) appeared very dark in the morning sunlight. This was due to the fact that he had raised his back and rump hairs on end – possibly out of aggression or fear.  The small bodied/large antlered deer (yes, this is a bit confusing) did not puff up.

After a very brief encounter (which you can see here in this video) the large antlered buck passively entered into the woods at the point where the smaller antlered beast exited. The second buck lowered his hair, raised his tail to drop some raisins, and with open panting mouth, continued on his doe trail (see below).

In the end, there was no fight and I was only slightly disappointed.  As is the case 99.9% of the time there are no contests between unequal males and it was good to witness one of these encounters. In this scenario it almost appeared that the second deer won the “non–fight” and I’m guessing it was on body size over antler dimension. Maybe there is some mental formula combining point count with body mass divided by will and multiplied by the desire to stay un-hurt. Heck, if I am confronted with a muscle-bound gym master with a small head I would also yield the floor. Come to think of it, a lot of muscle bound types have small heads don’t they? At least I had good grades in high school.

November 17, 2011

A Walk Across Michigan (State)

Filed under: Uncategorized — wykes @ 9:21 pm

On a recent trip back to Michigan State University, I had to occasion to wander a bit on campus. I was chaperoning for my daughter’s orchestra students as they participated in a day long workshop, but I did have a few “breakout” opportunities during the day. It had been at least 3 million years since I had graduated from State and the beautiful fall day was too much to resist. The northern portions of the grounds have changed little since my tenure there.

Now, if you (as a regular reader) haven’t figured it out by now, I am a hunter-gatherer by nature. I seek nature where I can find it. I gather much of my experience up in my camera and often end up putting some of it in my pocket. Even the relatively cultured environment of a campus offers “h-g”  types such as myself some forage chances. This particular trip, although limited to only a few hours duration, was distinguished by variety, if nothing else.

Take the well-cultured environs of the Beal Gardens, for instance. There among the rows of browned stems and stake labels marking vacant spaces, the tendrils of a lone trumpet vine hung limply on its support cage. In mid-summer this spot would be glowing with bright orange-red trumpet flowers but in November only long slender seed pods remain. The label reminded me that Trumpet Creepers, as they are known, are actually native to the S.E. United States. In northern climes, however, they are often treated as troublesome suffocating invaders – thus earning the unlikely names Devil’s Shoelace and Hell Vine.  Wow, them’s tough woids, eh?

The Trumpet pods are not evil, in and of themselves, but these pointed narrow pods each contain thousands of winged seeds which serve to propagate thousands of potential tools of the devil.  On this cool November day, I could appreciate the pod and its structure without judgment. When opened, the trumpet vine’s tongue is exposed for observation (note that it is not bifurcated). It was an interesting pod – n’est ce pas?

A large mangled Yew bush provided yet another insight into small things. This Yew was not in the gardens, but instead was adorning the front of one of the distinguished old halls. Apparently the grounds maintenance crew was in the process of trimming the things back after a half a century of rampant growth. The raw cut stems instantly attracted attention due to their nearly blood red cores (heartwood). I later determined the age of one 2 inch diameter segment to be at least 55 years old. The wood of the Yew shrub was hard and dense and the rings were spaced very close together.  It is no wonder that yews are some of the oldest plants on the planet– some individuals attaining 2,000 years of growth. It is a tree that was familiar to the likes of Otzi, the famous iceman, who carried an unfinished bow of yew wood with him into the mountains. I too carried my yew specimen in my pocket but did not end up frozen into an awkward position by the end of the day.

Under the newly exposed ground beneath the yew patch, a Squirrel skull revealed itself. The campus is chock full of both Fox and Gray (Black) Squirrels. At some time in the past, some poor sick nut-cruncher crawled into the safety of the bushes to die. My immediate question in this case was whether the rodent in question was a Gray or a Fox Squirrel. I also pocketed this example for later determination since I could not decide at the time.

Later, I measured the piece for an answer. According to my mammology texts, Gray Squirrel skulls are always 2.5 inches or shorter. Fox Squirrel skulls are always 2.5 inches or longer. So, you can see the initial lack of identification clarity when my subject turned out to be exactly 2.5 inches long! The dentition (tooth) test leaned toward Fox Squirrel (see underside view below) because Gray Squirrels usually have one extra little premolar in front of each row of molars, while Fox Squirrels do not. This skull had no extra premolars.

Because 1% of Gray Squirrels do not have this extra set of teeth, there was still a very slim chance my skull was simply a toothless Gray. My last test involved a black light and a darkened room (similar to some of the rooms on my old dorm floor back in the 70’s). Apparently, Fox Squirrel bones glow pink when under black light because they retain a chemical called porphyrin. I’m not sure that ONLY Fox Squirrel bones glow pink, but never-the-less, it sounded like some worthless fun. So, take a look below and see if you can tell if my specimen was glowing pink or it simply looked pink under the pinkish glow of the black light bulb.  Either way it was a groovy experiment, man.

Speaking of groovy, my final find of the day proved to be the most mind-blowing of all …like, oh wow man. On a well worn dirt trail – the kind that always develops in the grass angle where two sidewalks meet at a sharp angle – I found a projectile point. Yes, on a shortcut that I myself took many times during my illustrious career on campus (mmmmmph years ago), a flint projectile point sat on the dirt exposed by the rain and the constant scuffling of educated feet.  Because many of those educated feet were supporting distracted educated heads attached to cell phones, it is my educated guess that hundreds passed over it without notice.

It would be tempting to label this find as an arrowhead, but it was not. Based on style, the serrated edge and bifurcated base on this little point (the tip was broken off) it dates back to the Archaic period around 8,000 years ago. This style is as distinctive as the identifying lines on a piece of yew wood, the contours on a Hell Vine pod, or the wide forehead look of a squirrel skull. The point long predates my campus occupation. It even pre-dates Otzi and his kind. It harkens back to a time when the Michigan State campus was only four thousand years fresh out of the mantle of glacial ice.

My campus ramble only took me an hour or two, yet it took me farther than my feet could possibly carry me (and gave me a chance to use the word bifurcated two times).

November 11, 2011

Clocking the Bear

Filed under: Uncategorized — wykes @ 11:42 am

In late autumn there is alternate way to measure one’s vehicle speed down a country road other than mph. You can use the cpm method. On the outside chance that you have not heard of this, cpm stands for “caterpillars per mile.” And, on the even slimmer chance that you don’t know what I am talking about, please allow me to explain (or attempt an explanation without hurting myself).

The caterpillars in question are the famous larvae of the Isabella Tiger Moth better known as Woolly Bears. You know, those fuzzy black and red fellows who are believed by some to prognosticate winter weather. Note that I said “are” rather than “were” in the previous sentence because there are a few believers that stick to this fantasy to this day. Of course, not everything you believe in comes true (for instance, I believe that someone will come up to my door someday with a huge silver tray loaded with unimaginable riches and offer it to me). Such unverified beliefs are called folk tales – they are fun as long as they are kept “folksy.”

In truth, if the Wooly Bear could predict winter weather it most certainly would. These larvae overwinter as caterpillars so it would be nice to know what kind of winter to expect. But, alas, they have no more idea than we do and so they dash about like headless chickens just before the hard frosts hit. On sunny fall days, you will see herds of them darting across the road – just to get to the other side (obviously inspired by those headless chickens to do so).  They are seeking hibernation sites, but still it seems like a very random process. Oh, in case you take exception to my use of the word “darting” in reference to caterpillar motivation, please hold on a minute because I will get to that.

The point is that on those special sunny days you will often see so many of the road-crossing Woolly Bears that you can literally measure your forward progress by counting them. This is the where the cpm rating comes in. I recently recorded a cpm of 10 while driving down 3 miles of a parkway. There were approximately 10 caterpillars for every mile of roadway. My mph was around 15 and my progress resulted in a ccpm rating of approximately 1 – that’s one crushed caterpillar per mile).

The amazing thing about watching Wooly Bears is that you will notice how fast they really are. I’ve read that these fellows can clip along at .7 mph. For a two inch critter with 16 legs this is a pretty good pace. In fact, I thought that number might be a folkloric figure rather than an actual one. You can’t believe everything you read (I offer my blog as living proof of this principle).  No, I needed to verify this somehow.

I don’t own a speed gun, and was not about to corner a local policeman and ask him to clock a caterpillar with his radar gun. I felt that this request would have been misinterpreted. So, I went straight to the field, employed a local Woolly Bear to walk the walk (see the movie clip here), and then hit the calculator. My math skills are legendary – as in folkloric, or imaginary if you prefer – but I pulled out all the numbers I could manage (see my figures below if you don’t believe me).

Figuring that my subject walked a set distance in the set time allowed, and taking into account that it was a Tuesday and that the moon was waning, I divided the co-sine by the sum total of the weed whacker, and arrived at a figure of  .6 mph.  Even considering my considerable margin of error (more like an expressway of error) this was amazingly close to the published figure.  Further considering that the published figure was probably drawn from the use of a real radar gun (the same gun that once clocked a stationary woodlot going 90 mph), I was satisfied. Woolly Bears can haul their little bear butts at an average rate of .6-.7 mph.

Unfortunately, the cpm rate will soon be down to 0 when the snow starts to fly. So, no one will have a good opportunity to prove me wrong until next year. Gee, that’s too bad.

November 6, 2011

Nut Gnashing with the Reds

Filed under: Uncategorized — wykes @ 7:32 pm

The hollow in our dying Red Maple has yielded yet another crop of baby Red Squirrels. At least four of the little things are prancing about the yard, although it is hard to tell exactly how many there are. They are dashing about like so many sizzling onions on a wok – spastic balls of pure energy who will at times spontaneously jump into the air as if electro-shocked. They often engage in endless round-the-trunk chases.  About the only time they actually remain fixed to one spot is when they are dismantling walnuts. This is something they do well and often. It is in this endeavor that one can see that these rodents do have a serious side.

I could say that they handle walnuts as skillfully as a monkey handles a peanut, but that would be a silly thing to say because I’ve never seen a monkey handle a peanut. I do know that a monkey would not be equipped to handle a black walnut, but any squirrel with half a brain could probably handle a peanut better than any monkey. Now, you could teach a monkey how to use a hammer or a nutcracker to perform the task, but that would be cheating (and potentially dangerous to the trainer).  It is fascinating to see how my young squirrels – creatures of half a brain – have already mastered the ultimate challenge offered by the Black Walnut. No tools needed other than those gifted to them by the grace of the great squirrel gods.

Black Walnuts surround their seeds with a thick green husk. This coating turns rotten black once the nuts fall to the ground and this poses the first hurtle for any would be nut predator. The nut shells themselves are extremely hard and the nut meats within are compartmentalized and shoved into multiple nooks and crannies. This is the second and most formidable task for the nut eater to overcome. There is nothing easy about extracting walnut goodness. It is the tree’s intention, of course, to be difficult, but we can talk about that another time.

It was my original idea to time the squirrel’s nut processing procedure from discovery to completion, but this proved difficult. Not every nut gathered by the diminutive Red Squirrels was immediately eaten. Some were carted off to secret hiding spots and others were dropped while in transit.  Some were de-husked and abandoned when two individuals spontaneously combusted into a bout of “round the tree – you after me, me after you.” Others quit in mid-nut for no apparent reason. I did manage to put together a string of observations coming to the conclusion that it took approximately ten minutes to do the job. Ten minutes out of the life of one of these dynamos is a serious time allotment.

The greasy husk is plucked away in rather short time via a series of peeling bites. I do not know how these creatures avoid staining their faces, but they do. Then, holding the nut firmly within the full eight finger grip (Red Squirrels have surprisingly large front feet), the chisel-like teeth are employed to begin gnawing away the shell. Leverage is gained by hooking the top set of incisors into one of the many grooves within the surface of the nut and pulling up the lower teeth to meet them. The four incisors are exceedingly sharp-edged and literally “iron coated” (thus the yellowish orange appearance). Powered by strong muscles they cut through shell like butter. Unfortunately the sound of this activity is literally grating on the human ear. (I wonder how Red Squirrels would react to the sound of fingernails on a chalkboard?).

Once an opening is made into one side of the walnut, these same incisors scoop out the nut meats from every angle possible. The squirrels then turn the nut over and make a new opening from the other side. Sometimes they gnaw out a trough from one side to the other.  When they happen to enter the nut from the top, they simply chew away half of it in order to expose both nut chambers in the process. Red Squirrel work is easily identified after the fact (see above). And, because these squirrels are active throughout the nutting season their “work” piles up at the base of the tree.

There is very little nut left inside the shell carcass once a Red Squirrel has finished its task. I watched as a tentative looking White-breasted Nuthatch approach one of these empty shells. It carefully eyed the shell from all angles and then leaned forward to peck out a few scraps of nut dust. After a few more discouraged glances it flew off – there was nutt’n left for a self respecting nuthatch to hatch.

**NOTE: In case you didn’t see enough, I’ll post a few more Red-Squirrel movies  and pics in a few days.

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