Naturespeak A naturalist's view of the world

January 31, 2009

Hot Bird on a Cold Day

Filed under: Uncategorized — wykes @ 10:29 pm

Thermoregulation. That’s the word of the day and a super fantastic Scrabble word to boot. It refers to the way animals maintain their body temperatures by either cooling off or heating up in response to surrounding air temperatures.  In the midst of a winter Scrabble game, it’s the heating up and staying warm part that matters. Little creatures, such as the White-throated Sparrow pictured above, are especially concerned about  these matters. This is the little guy that got me thinking about such things.

Little birds happen to be especially hot little packages.  On average they have a running body temperature of 104-108 degrees F . Ounce for ounce, birds have a warmer body temperature than mammals of equivalent size. Bigger birds are closer to the mammal model than the smaller ones, however. I’m talking about the wee (“wee-er,” if that’s a word) birds in this case. In an effort to stoke their tiny furnaces they need to take in a lot of calories and burn a lot of oxygen. This means their rate is nothing short of phenomenal.  A small fowl’s heart rate can be up to in the 400-1,000 bpm range. When you compare this to a human exercise rate of only 160 bpm, you wonder why these things don’t just blow up! Winter poses a whole set of problems for such hot-headed birds.

As you can see, this sparrow was doing his best to stay warm on a bitter January day where the temperature was about 9 degrees F.  To achieve his goal, he basically curled up into a fluffy ball. From a different angle (see here) the thing looked more like a dust bunny than a bird. Every feather was erect, his feet were withdrawn,  and his head was tucked around so deeply into the back feathers that it appeared to be lost. He was so involved in his thermoregulatory endeavors that he did loose his head, in a manner of speaking, because he ignored his predatory avoidance endeavors. I, the potential predator, was able to crawl up to within inches of this fellow without alerting his alarm system.

A few days later I came upon another one of these sparrows. The day was “warmer” at a balmy 15 degrees F, so it was puffed out but not balled up. He cracked an eye open just enough to check me out (see below) before resuming his energy conservation tactics.  Other birds are doing the same thing as well – like this inflated winter robin (see here). There is more going on with these little peeps than first meets the eye. The small scale winter bird has many metabolic and behavioral tricks hidden under those feathery sleeves.

To stay alive, a bird needs to find a balance between producing heat and conserving it. Different small birds have different responses. Cold weather, especially that rendered brutal by high winds, causes sparrows to increase their rate of heat production. Chickadees can go into a state of controlled hypothermia if necessary and drop their body temperatures by up to 15 degrees F. Redpolls can eat like pigs and keep their furnaces going at their normal rate. The major way for birds to produce the quick heat they need is to shiver. First, by shaking their large flight muscles and then adding in some quivering leg muscles at lower temperatures, heat is generated.

Conserving that precious  heat, once produced, is equally as important. Changing shape, like going from an oval to a round shape, decreases the amount of surface area. Erecting feathers traps a surrounding layer of air. The action that brings these feathers up is akin to the muscular action that creates goosebumps on us, by the way. Tiny feet are protected from frostbite through a system known as counter-current blood flow. In short, this means that the warm blood coming from the body into the foot transfers its heat to the cold blood returning from the cold little toes.  The cold blood is brought back up to body temperature before it gets back into the body.

On top of all this “body stuff,” the smallish bird has to use that hot little head to make some behavioral choices. They need to choose roosting spots out of the wind and position their bodies into the wind if necessary. For instance, my fluff ball White-throated Sparrow chose his spot away from the wind and next to a building. You’d think standing on a cold slab of cement would be a poor idea, but the fact is that the building and the concrete store some of the sun’s heat and then radiate it out as the temperatures drop. Tree trunks and rocks will do the same thing which is why sheltered birds seek these spots for the few extra degrees of comfort they receive. On another level, one study even showed that many birds choose to feed later in the day so that they can have that additional energy boost to get them through the long cold night.

These are all things you can think about when next you nestle deep into the folds of your down jacket and curse the north wind. Little birds don’t curse – it’s a waste of energy.

January 28, 2009

Owl Things Considered

Filed under: Uncategorized — wykes @ 11:02 pm

I’ve just finished up with a four owl week. During this late January period of frigid three-dog nights, experiencing a couple of two-owl days ain’t bad. But, when you can put a few of these multi-owl days together and come out with a four owler, well, that’s something. Some would classify my effort as a mere two-hooter happening, since two of the four owls of which I speak were either dead or not present at the time of their “discovery.”  To those naysayers out there, however,  I will boldly say “frankly, my dear, I don’t give a hoot.” This thing is about the birds, not the man.

My first encounter was with a Saw-whet Owl. Well, O.K., I didn’t actually see one of these soup can sized birds but I found one of their snow angels – I think.  Take a look at this picture (here) and you’ll see what I’m talking about. My identification is based on size, proportion, and something else which I’ve since forgotten. Anyway, these tiny owls feed on song-birds and mice during their winter stay. The songbirds are as vulnerable as ever, but the mice are able to get about under the protective white stuff with relative impunity. They are, to put it bluntly, loving it. Aerial predators, such Saw-Whets can’t see them but they can hear them them through the snow (when mice burp, owls listen!). I believe this track shows where one of the owls plunged directly down into the snow at the base of a Queen Anne’s Lace to nab an over-confident and chatty little rodent at its base. The wingspan mark, measuring around 17 inches, combined with the short tail mark point to this species as the maker. I can’t tell you if the plunge was successful other than it successfully produced an nice little snow angel.

The subject of Screech Owls came up while listening to a morning report on NPR a few days ago. Obviously lacking any solid new to report, the local station aired a short segment on how Screech Owls are suffering through this winter. The deep snow, they report, is keeping them from their food and they are suffering – you can hear their painful hunger-driven screeching ringing through the night woods. A well meaning commentator, when asked about this situation, suggested that people put out bird seed to help. I heard my wife laugh from down the hall when this comment aired.  I’m sure he meant that the seed would attract mice and birds which, in turn, could be eaten by the owls, but there was no real science to back up this claim.

With visions of screech owls lining up at feeders throughout the north country, I headed off to work that morning thinking about the reality of the claim. The best thing to do would be to verify the presence of dead screech owls and examine them for signs of starvation. No sooner had that thought entered my head than I spotted a dead screech owl a block from my house! The bird was dead on the road – the victim of a car strike – but the circumstance was a bit spooky. I retrieved it and performed a little bit of science on it. This bird, an ashy salt & pepper gray phase individual, was not starving at the time it met its untimely end. Its breast muscles were plump and full up to the keel. I suppose it could have been heading for the nearest feeder, now that I think about it.

Detailed examination of the bird revealed a 19 1/2 inch wingspan which provides a comparison with the smaller span of the Saw-Whet mentioned earlier. I spread the feathers out in order to get a good look at the silencers on the wings. The leading edge of their primary (wing) feathers have a comb-like structure which evens out, and therefore silences, the rush of air over the wing (see here). All owls, at least the night-time fliers,  have this stealth feature. All owls are also equipped with impressive talons. Even tiny owls like the Screech, have formidable talons and rough-padded feet for securing and killing prey… such as feeder birds, for instance (see here).

My third owl was not only alive, but it was in the midst of performing one of the truly remarkable rituals of the natural world. The bird was a Great-horned Owl and she was sitting on eggs.  Great-horns begin their courtship in early winter and lay their eggs by late January or early February. By doing so, they beat everyone else to the punch kinda like a baseball fan camping out at the stadium while snow is still piled high on the seats.

Great-horned Owls take over the old nests of Red-tailed Hawks , Herons, and even Bald Eagles long before these birds would even think about nesting. By the time the original nest makers return they find their nest occupied and will move on to make another nest. This particular owl opted out of the nest stealing game and decided to situate herself in the cavity of an old cottonwood snag (see here). The snow downwind from the tree had several downy feathers scattered over the surface (see here).  A closer look (see below) shows her sitting hen-like on the nest.  This a very non-owl like pose although it is made significantly more owlish by those intense yellow eyes. The impact of this scene is made especially poignant when you consider that the overnight temperature just previous to this shot was -1 degree F and the daytime temp was hovering at 12 degrees F. She will go through much more of this in the coming month before her young finally hatch.

My last owl of concern was a Long-eared Owl. These wintering birds are creatures of habit who tend to return to the same daytime roost day after day. They prefer the cover of dense  tangled vegetation or conifer trees. Often they roost together in informal groups and it is not unheard of to find up to 20 owls in the same tree. I believe the proper way to refer to such a gathering as a parliament. My bird (someone else found it and told me about it, so it’s not really mine – but then again it’s not really theirs either) was a solitary member of the House of Commons.

He was alone and somewhat contented when first approached (see here). Squint-eyed and upright, with “ear tufts” erect, he was the near-perfect imitation of a stick. You can see why they can be so hard to spot when employing such camouflage. My presence irritated him for some reason (this happens in my presence quite often) and he began to puff up into a defensive display (see the photo at the top of this entry). With those intense yellow eyes burning a hole right into my soul, the bird raised every feather of it’s body and dropped a wing down. Overall, the act served to enlarge the owl to nearly three times it’s starting size (see below). “Look at me -ain’t I frightful” is the intended message which is reserved for potential predators. Owls have on their back bigger owls to bite ’em, you see, so a good defensive act is always a good backup.

This was my signal to back off.  I didn’t want to flush him just for the sake of a picture. By the time I was ready to turn around, the Long-ear was in full puff mode. He started to blink continuously and look nervously about. My last photo caught him in mid blink and it is the best shot of the four owl week (see here). A translucent nictitating membrane, which serves to cleanse the surface of the eye, is employed from the upper inner corner of each eye. It is a serendipitous occasion to catch this motion in mid-wipe.

Owls are, in fact, serendipitous creatures who don’t allow too many viewing opportunities.   This is why a four owl week is not something that can be expected on a regular basis. Every view has the potential to be a learning experience. There is actually a potential to have a five or six owl week in these parts, so you can bet owl give it a try.

January 25, 2009

In the Presence of Eagles

Filed under: Uncategorized — wykes @ 9:31 pm

Numbers don’t mean much by themselves. They don’t breath, cavort, fly, or dive into the water. When combined with living things they do begin to shed their sterility and begin to breathe. So, when I say that there were at least 216 Bald Eagles counted along the Michigan portion of the Lake Erie shore during the recent Christmas Bird Count, these particular numbers have the potential to jump off the screen and shout “Hallelujah!”

Yes, you read correctly. From the state line up to the Detroit River mouth the combined totals of the Rockwood and Monroe Audubon bird counts tallied over 200 individual eagles. Not so terribly long ago, one eagle could be considered a life sighting in S.E. Michigan. The effects of DDT and other chemicals having sucked the lifeblood from the once thriving local population, the bird was all but extinct except in the northern portions of the state.  Today the eagle is not only back, but continuing on a population rebound across the Great Lakes country. Take a look here at this photo (see here) taken by birder/photographer Jerry Jourdan showing 43 eagles off the Monroe County shore and you’ll get the idea. Hallelujah!

Perhaps the most surprising aspect of these numbers – these breathing, cavorting, and diving numbers – is that these are winter birds.  The spring/summer breeders and migratory numbers are certainly respectable, but winter is the best time to view our neighborhood eagles. Like Canvasbacks and Tundra Swans, Bald Eagle numbers peak during the cold season. Like the before mentioned waterfowl, these birds of prey gather here along the waters of the Detroit River and Lake Erie to partake in the abundance of food. Unfortunately for the waterfowl they, along with the fish life,  are the object of the eagle’s partaking.  Lots of duck and fish will die within the clutches of  a set of talons, but we are richer for it.

Our wintering population is not only phenomenal but it is also accessible.  You can see the birds along many waterside areas, but one of the easiest viewing opportunities is offered at Lake Erie Metropark. By driving the Cove Point Picnic area you can watch the birds from your car window.  I say to you, therefore, ” get thee down to the Erie shore to see eagles.”  I say also that you will be in the presence of eagles sooner rather than later.

The best conditions are present when there is a significant ice shelf along the water. This situation concentrates the waterfowl and the eagles. Not a day has passed since mid-December without a half a dozen or more eagles perching out on the shelf ice along the open leads of water at Lake Metropark. Most of the birds are quite far out  and they look for all the world like patient ice fishermen. On an icy morning, they will stand there like evenly spaced sentinels -the wavering cold air issuing from the river ice creating a quivering mirage that appears to make them shift about. One will occasionally jump up into the air and shift position or plunge into the water after prey.

This morning, I watched as five eagles cavorted (see, there’s that word again) about a half mile out on the ice.  They would engage in short circling flights and replace each other’s position like a living version of the recycling logo. The background scene to this dance was the shimmering far shore of Canada and the looming red spectre of a Canadian Coast Guard Cutter breaking ice in the Amherstburg Channel. The cold mirage made the northbound cutter look like it was hovering just above the ice. Between the shore and the eagle activity, thousands of Canvasback ducks bobbed like white corks and filled nearly every inch of the open water space.

In all, the setting surrounding the winter eagles is somewhat unreal. The birds do come in to shore from time to time for closer inspection. Most of the birds are immature and lack the white head and tail of the five-year old plus birds. They are dark brown with random white streaking like the bird I photographed above.

Remnants of dis-articulated ducks and fish remains are in evidence under some of the shoreline trees. For the most part, however, the eagle sign can only be found out on the ice. I spied one of the eagle landing spots on the frozen shelf and ventured eastward from shore to take a look (see here). At this spot you could plainly see the feather marks and a central spot where the bird finished off what looked to be a fish. It was hard to tell exactly what the prey was because there were no identifiable pieces left. Not too far from this landing point was another much clearer set of foot prints (see below).  Here the bird performed a two-point landing, sauntered about six feet, shuffled a bit, and then took off.

A detailed look at one of the prints (see here) provides a rare view of a very transitory thing.  Here, it can be said, is where the “Eagle has landed”. Eagles don’t make tracks too often because they don’t come to earth too often. When the Eagle spacecraft landed at Tranquility Base in the Sea of Clouds three decade ago, it left tracks that will mark the moon dust for thousands of years to come. This track, photographed only a few days ago, was erased by shifting ice in only a few days time.  It’s spot has been taken up by a new patch of snowy ice and awaits yet another landing. The good news is that there are now plenty of eagles around to make that landing.

January 22, 2009

Death in the Snow: Part II

Filed under: Uncategorized — wykes @ 10:17 pm

If fog comes in on little cat feet, then surely death comes on cat-owl feet. It glides in on silent flight and snuffs life into the powdery snow (with apologies to Carl Sandburg). The cat-owl, better known as the Great-horned Owl or Flying Tiger is often characterized as a “ferocious”  predator in the literature. It ‘s not really fair to see anything other than instinct behind the predatory skills of this owl. They are persistent, efficient, and eclectic in their tastes – cool and able rather than ferocious. Now, Rabbits, if asked and assuming they could actually answer, would certainly call these large owls ferocious in the extreme. “Cold killers, that’s what they are. Maniacs out for blood and the thrill of killing our kind” they’d say before bounding off to sooth their deep angst with a sprig of tender blackberry vine. Great-horns are rabbit specialists, you see. These powerful birds, with a wing span of up to 5 feet, are one of the few local birds of prey that can take down full grown rabbits.

The deep whiteness that now blankets the countryside  provides written testimony for the nocturnal efforts of the Great-horned Owl. I came upon a fresh owl kill site alongside a snowy back country road a few days ago.  At a point where the road cut through a brushy wood, rabbit tracks peppered each side of the way. This was a rabbit crossing where timid nightime cottontails dash over the open space seeking, I guess, those tender blackberry vines. I’m sure the vines are equally as tender on either side, but those on the “other” side are always more tender.  No sooner had I recognized this as a  crossing point than I spotted the distinctive mark of a kill to my left (see below).

A fan of feather tip marks surround a central spot matted with blood, guts, and hair. A pile of innards,the digestive tract, was deposited off to the side. It’s hard to imagine that crows would turn down  fresh innards on a cold day, so I imagine they hadn’t discovered the place yet.  Apparently the owl spent enough time at the spot while dismantling the bunny to melt a patch of snow under its warm bottom.

Taking in a wider look at the site (see here) reveals that the owl probably grabbed onto and killed the rabbit about six feet away. There is another set of wing marks there along with a drag mark connecting it to the final eating  location. Owls use their powerful claws to literally crush their prey. Once the bunny was held in the predator’s grip, there was little it could do but wait for its trip to the great blackberry patch in the sky. Once the prey was dead, the owl used it’s sharply hooked beak to rent it asunder.

There were several other snow marks in the vicinity made by the owl. One was a brush mark made by the primaries after a low pass – perhaps made as the killer flew in low to make the kill (see title picture). Another spot shows where it plunged into the snow for some reason (see here).

Great-horned Owls will tackle  just about anything. Although rabbits are high on their list, they will eat mice, squirrels, pheasants, songbirds, crows, snakes, fish, and chickens if the opportunity presents itself.  One even attacked a white spot on the back of a very surprised collie. I often find myself getting asked if Great-horns will take house cats. As you might expect my answer, often accompanied by a smile, is that they will and often do. Cats and rabbits are about the same size.  However, I do try to clarify things by stating that they don’t take true house cats but only cats allowed by their owners to wander about in the great outdoors.

I was doing a bit of research on this subject and found several passages in Arther Cleveland Bent’s classic 1937 book on Birds of Prey. Mr. Bent had little to say about rabbits except that Great-horned Owls eat them with relish, but he did report at least three instances where cats were taken. One of them proved to be too much for the owl to handle and it had to drop his ferocious prey!  Allow me to quote a passage in which an observor, Mr. Oliver Austin narrates another cat vs. owl event. The man  frightened an owl off it’s kill and he “…stopped to pick up it’s prey which to my surprise (and delight) proved to be a half-grown house cat.”I find it comforting to know that someone, way back when, wrote a passage which sounds like I wrote it.  I’m not sure even I would have said “delight,” but there it is.

I was delighted to have found the rabbit kill site – not delighted at being in the presence of death but because it gave me an opportunity to record and memorialize a moment in natural history. This bunny did not die in vain.  The rabbits probably do not share my enthusiasm.

January 19, 2009

A Floundering Pheasant

Filed under: Uncategorized — wykes @ 8:54 pm

Let me lay a startling statistic on you.  Although this figure varies between regions of the country, it is estimated that up to 75% of our annual crop of Ring-necked Pheasants die each winter. When pheasants enter into the “autumn of their lives” they can reasonably expect that there will be no second summer in their lives. With a track record like that you might come to the conclusion that these birds are wimps when it comes to toughing out the cold season. You’d think a flock of scarlet macaws could do better than that, but you would be very wrong. Ring-necks are actually pretty tough customers and are able to withstand almost any weather condition. It’s just that they have their limits.

While I’m fairly certain that the macaws would experience 100% population mortality if subjected to one day of northern winter, I have no documented evidence to back this assumption up.  I also do not advocate putting this to the test either. Macaws are made for life in the tropics, and that’s that.  Ring-neck Pheasants, on the other hand, are made for northern latitude winters. These birds originally hailed from China where they evolved with weather conditions very similar to our own. The average high/low January temperatures for Beijing, for instance, are 35 degrees F/14 degrees F.  Here in Monroe, Michigan we average a very similar 30 degrees F as a high and 15 degrees F as a low. Another factor to consider is that Ring-necks were introduced to this country about a 100 years ago and have had ample time to adjust to the the harsher conditions found in portions of their adopted range such as the Great Plains. So, why the high pheasant flopping rate? 

I have two answers to this last question. First of all, this mortality rate is not especially high – it is a death rate which is typical of many very successful creatures. Young, sometimes dumb, and often weak yearling animals just don’t have what it takes to make the cut. It’s not survival of the cutest. This may offend our human sensibilities, but it is as much a part of reality as gravity (and one which should give us a good sense of the gravity of  natural survival). Secondly, this brings to mind that about the only thing winter pheasants can’t stand are blowing snow and extreme cold. A string of normal winters will be balanced out by a few really bad years. This, unfortunately, is a bad year.

I spotted a Ring-neck (pictured above) plowing through some deep snow in western Monroe County last week. The bird was belly deep in powder and wandering somewhat aimlessly (see his tracks below). I believe he was contemplating crossing the open field area but was hesitant. You can almost see the indecision in his trail (O.K., I’ll go…No, better not…Oh, why not…Nope, too far…). Pheasants can fly, but prefer to walk. Given the brutal sub-zero temperatures and deep snow – deep for these parts anyway – this bird was looking a little worse for wear and probably trying to limit his energy output.

It wasn’t until the rooster spotted me an made a dash for cover that I realized he only had one tail feather left.  He proudly held his single point of pride aloft as he disappeared into a thicket. Pheasants require a good mix of cultivated field and dense cover (marshes, brushy fence rows, and weedy ditches) in order to survive these trying times. Why this bird was attempting to leave his cover in the first place is anybody’s guess.

These winter birds usually don’t die from outright starvation. They manage to find enough grain, weed seeds, and berries to get by. Some also get taken by Red Foxes, Coyotes, or Great-horned Owls as well. Oddly enough, the birds are more suceptible to the weather itself. They can die of suffocation if caught in a high bitter wind without shelter. Ice will build up and clog their their nostrils and eventually create an ice block in their mouth as they attempt open it up to breathe.

Many of the winter-killed Ring-necked Pheasants won’t actually die until very late winter or early spring. This is the point at which their reserves are totally used up and they just “run out of gas.” Female birds stressed out by a severe winter won’t be able to produce young either, so the entire population takes a dip. The nice thing about averages, though, is that what goes down must come up and unless there is a string of severe winters, the pheasants will bounce back.

I hope my uni-plumed bird male is one of the lucky 25%. He may be a floundering fowl, but he’s got a good genetic background to back him up. He definitely is keeping a stiff upper lip, that’s for sure.

January 16, 2009

Sparrow Does the Chicken

Filed under: Uncategorized — wykes @ 11:11 pm

White-throated Sparrows take winter very seriously but there’s something about their demeanor that takes the edge off the season for the rest of us. All active winter wildlife (the dead ones don’t count) are engaged in a daily struggle for survival.  The search for food and shelter can be an all-consuming effort when things get tough. White-throats are always searching about, foraging, calling, or gathering into small rambunctious feeding flocks. In short, they are constantly reminding us just of how hardscrabble their tiny lives can be. They do it with such grace and dignity, however, that they make it look natural.

Although they offer some pretty fascinating  patterns, most sparrows are relatively plain brown birds. White-throated Sparrows stand out among the sparrow set because of  their striking black, white, and yellow crown markings. Being good looking is a definite eye-catching trait for bird and man alike (not this particular man, mind you). A key characteristic, and one which probably goes without saying,  is their white throat set against a buffy gray breast (see above). Hardly anything in nature is as it first appears, which is why I’d like to get back to these markings in a moment. First, we need to take a look at how these sparrows forage.

White-throats spend a large part of their time on or near the ground. They are ground gleaners, which means they specialize in  finding hidden foodstuff on the ground. Their discovery technique involves scratching about much like tiny barnyard chickens. By hopping forward with both feet and then briskly pulling them back, leaves and snow cover are sent flying and a space is cleared to reveal what lies beneath. During the winter they expect to reveal enough seeds or hibernating insects to keep them going.  Take a look at this short video I made of one of these birds actively burrowing into some bark chips (watch movie here). It was an especially cold day and the promise of a sheltered patch of uncovered ground was too much for it to ignore. This fact also explains why his feathers are fully puffed out as a buffer against the single digit temps.

Burrowing is the only word to describe what these little guys can do. Given the proper incentive (that being food) they can dig an inch or more into the ground. A determined individual will dig a series of small potholes over a large area if the rewards are sufficient to reward the labor. It is a deliberate act on their part to nearly deplete a spot before moving to another. They are not normally social birds, but during the winter small flocks of feeding White-throated Sparrows will gather together for mutual safety. Large groups can afford to be further from cover, so the benefit is clear. There is a definite hierarchy within these impromptu groupings. I guess you could call these ground rules to insure that there is enough to go around. Dominant birds, for instance, are allowed  to pick areas closer to cover than younger subordinate birds. It is a matter of natural fact that the more exposed birds – i.e. the yearlings – will get picked off more frequently by predators, but these things are probably not brought up at the team meetings.

There is one more subtle mark of rank within a White-throated Sparrow society group. These sparrows come in two different genetic “morphs” that exist side by side – distinguished by the intensity of their colors. Until about thirty years ago, these color variations were considered differences between adult and juvenile traits, but such turned out not to be the case. The so-called “tan striped” individuals have muted colors and off-white crown stripes. The individual in the above picture, and the one in the video, are examples of this type of  dull bird. “White-striped” birds, like the one shown here, are brightly marked with bleach-white striping and bright yellow spots above the eyes.

Being known as a dull bird might seem like a downer but it has some advantages. It’s easier to hide from those nasty predators without that flashy white head pattern. Oddly enough, the opposite morphs are attracted to each other. Not every sparrow in this clan is on equal footing with the next. It is almost an avian case of reverse discrimination or something. Male tan-stripes prefer the romantic company of  female white-stripes and vice versa.

Admittedly, these affairs of the heart and morph don’t really matter in the dead of winter. The birds will have plenty of time to act out their romantic inclinations when they return to the boreal forests for the nesting season. The important thing now is to get through the winter without getting dead and to scratch your way to Springtime.

January 13, 2009

The Bark of a Winter Dogwood

Filed under: Uncategorized — wykes @ 5:11 pm

Spend anytime outdoors during the winter and you are liable to get red-faced. You’ll slip on the ice in front of your neighbor and embarrass yourself, scream at that plow driver who just scraped a load of snow across the end of your freshly cleaned driveway, or slowly loose the feeling in your nose and cheeks as you work to clear off that newly deposited load of snow. Getting flush is a natural emotional and physical reaction to the world around us. I guess you could say it makes us human, except for the fact that we are not the only living beings to get red in the wintertime. Red Osier Dogwood twigs do it too.

Now, before you get all red-faced with indignation at being equated to a stick, let me say outright that dogwoods do not possess souls and are not a threat to our identity (If you are a Druid, please ignore this remark as one made by an ignorant non-believer). These common dogwoods are  low, multi-stemmed shrubs found throughout our landscape. Like all dogwoods, they have an opposite budding and branching growth habit, but they are best identified this time of year by their bright coral red, or burgundy, stems.

It’s not necessary to take a closer look to appreciate them, but if you do (see here) you’ll see that the smooth shiny bark  has a gem-like quality. You will notice many raised ovals, called lenticels,  that pepper the  finish.  These serve to provide a white contrast to that marvelous background color.  At this point, you might be thinking  that this bark is probably just as red during the summer as it is during the winter so my point is pointless. Actually, however, this is not the case. Young Red-Osier twigs turn scarlet in the fall and stay that way through to the following spring. Around these parts they take on their red hue during the first half of October. Before that time, the branches are dull reddish purple to gray.

This dogwood species is a favorite for landscape plantings because it adds a splash of color to an otherwise colorless season. One horticultural variety, developed by the Minnesota Landscape Arboretum, is called the “Cardinal” because it produces an especially bright scarlet winter bark. Native basket makers have learned to collect the mid-winter twigs and use them just like willow twigs for basketry. The name “Osier”, by the way, is derived from the French term for  “Willow-like.”  “Dogwood,” for those who like complete thoughts, is believed to be a corruption of “daggerwood”  but no one really knows. “Red” means exactly what it says.

It is a singular and somewhat incredible fact that the Red-Osier turns red during the winter. Part of the reason for this pretty conversion has to do with a chemical change in the wood itself, but the explanation is not pretty. This species is considered to be one of the most freeze tolerant plants known. Scientists have been able to bring the temperature down to -269 degrees C (the same temperature as liquid helium) without killing it. I wonder if the scientist who made that observation announced his discovery with a really high voice due to the effects of the helium?  That would be embarrassing wouldn’t it!  Anyway, the mechanism works like this. The shortening days of autumn prompt the dogwoods to lower their stem water content and subsequently increase the amount of a chemical known as 24 kD protien.  This protein has something to do with the incredible freeze tolerance of this plant and probably stimulates the “red-effect.”

I wish I could say that the 24 kD protien is red colored and therefore directly turns the bark red, but I would be barking up the wrong tree to do so. Other dogwoods have this protein as well, but apparently not to the extent the Red-Osier does. This is why I say “red-effect.”  This word is derived from the French for “I don’t really know, but there is a connection.” Let’s just say this dogwood has a nice bark and be done with it.

January 10, 2009

An En-Deering Trait

Filed under: Uncategorized — wykes @ 10:34 pm

For my second installment of things re-considered, I will spend a few lines on the subject of deer. I don’t like deer – they are not pretty, graceful, or especially witty when it comes to ways of the wild. They reproduce like rabbits and leave a path of habitat destruction wherever they go.  But, I have to admit a grudging respect for them. It is one of my New Year resolutions to say something good about deer. As a male, I am envious of bucks and the sight of one will always cause me to freeze in my tracks. Whitetail Deer are a resilient, hardy and adaptable species and in some ways they outdo us in that regard. They also engage in play, which is an “en-deering” trait.

I recently encountered a group of yearlings and does one fine early January morning.  Each and every individual in this pod of deer saw me approach, but for some reason they allowed me to watch their antics for a short while. Being armed with a camera rather than a handful of food, I posed neither threat nor attractant. They were in the middle of a gaming session and weren’t about to stop.

Take a look at this movie (see here) and you’ll see what I’m talking about. You don’t have to be a behaviorist to see that the friskier members of this assemblage are acting like playful dogs. The wide-legged bow followed by a quick backup and a frantic gallop cuts across species from canine to cervid. Chasing is another identifiable play trait, except that these guys don’t roll and tumble when they finally make contact.

Most of the emotion is expressed through body language. Chief among these signals is the use of the tail flag. The bright white underside of that appendage is usually reserved for use as a warning flag. When spooked, fleeing deer will not only raise their “flag” but will wave it about as they run (see here). In this play group, however, their tails are not only flagged but are held tightly curled high over the back. Here, again, is a sign that deer are not as serious as they may first appear – there is a kernel of mammalian whimsy in their tail use. One of the things that seems to be missing from this apparently carefree session is sound, but it is there.

Listen carefully, and you’ll here a very loud “bleat” after one of the running deer brushes past one his fellow fawns. The sound is more like a quack from a toy duck. This vocalization occurs near the end of the video and is easily missed unless you play it over and over. It stands out because the rest of the session is silent.

Oddly enough, white-tail deer are a fairly vocal bunch, but they limit their voice performances to private performances. Most of the sounds are fairly quiet, but a social grunt used by does can carry over 300 feet or so. One of the most commonly heard of deer expressions is the loud “snort-stomp” in which a deer blows a rush of air through the nostrils and simultaneously stomps its  foot on the ground. This is intended to startle a mysterious observer (such as a hunter or a naturalist) into moving or otherwise revealing himself. Believe me, it works.

Outdoor writer T.R. Michels documents no fewer than 13 different deer sounds including tending clicks, grunt-snort-wheeze, and the ever-popular nursing whine. An addtional sound, the buck growl, was discovered a few years ago and became the inspiration for a new type of artificial deer call. I have not been able to find any reference that mentions this “play-quack” sound, however. Hey, maybe this observation will make me famous one day – or not. Actually I don’t care about that since I’ve already been rewarded by the opportunity to watch a group of deer doing something other than eating or bounding away.

January 7, 2009

The Mute Shall Speak

Filed under: Uncategorized — wykes @ 10:18 pm

It’s time for me to turn over a new leaf.  You know, with the new year and all that I figure it would be a good time to suck it in and pay homage to things I generally dislike.  This being a nature column, I am referring to such things as  cats, deer, phragmites, and…cats. I have a grudging respect for deer, so they won’t be hard to do. Phragmites, those plume-top habitat stealing plant monsters will be harder, but they too have some merit somewhere. I’ll do something about cats maybe next year or never – whatever comes first. No, I’d rather start my penance with Mute Swans, if you don’t mind.

Normally, I would only refer to Mute Swans as swimming hogs, but I am reminded by my better nature that these swimming hogs are not responsible for their obnoxiousness. Like weeds, they are simply living things that are in a place where humans don’t want them. People brought them here and allowed them to freely multiply and flourish. Like weeds they are exceedingly adaptable and durable and therefore successful as New World colonists. Just because they destroy aquatic habitats and chase away native waterfowl is no reason to hate them at a deep personal level.  In fact, saying  a few positive things about Mute Swans will neither hurt nor help them, so why not let me try, eh?

Mute Swans are sleek looking creatures. You’ll get no argument from me on this point. With their black-knobbed orange bills, graceful curvatures, and large size they are easy to identify from a distance (see the grouping above and the feeding ones here). They won over the early Europeans with their ceramically proportioned  good looks. This is the primary reason they were domesticated some 1,000 years ago. Never functioning as food, they were treated more as ornaments. In the 12th century “Twelve Days of Christmas” song, the geese did all the laying and the seven swans just swam around and looked pretty.

These domesticated swans were considered to be the exclusive property of royalty. The peasants were allowed their cheap little hedgehogs and bargain-basement geese, but swans could only be possessed by people of means. Every swan was marked and pinioned. Swan marks, brand-like symbols inflicted on each bird, were carefully recorded in official books that recorded ownership.  Most of these marks were carved into the upper mandible of the beak to create a permanent scar, although some involved punching holes into the foot webbing or clipping certain nails. All the swans belonging to the Earl of Surry, for example, had a Maltese cross on their beak, while those claimed by the Duke of Suffolk bore a pair of parallel lines over the top of the beak. An annual “upping”, or round-up, was conducted to mutilate the new crop of cygnets. A “cygnet,” by the way, is the special name reserved for the reproductive product resulting from the union of a “cob,”or male, and a female called a  “pen.”

Although it would be tempting to continue on the mutilation theme, I’d like to veer back in a positive direction and briefly examine the alleged muteness of this species. You’d think Mute Swans, in honor of their name, would be silent creatures but they are not. They find many ways to make a noise unto the world. Their whistling wing beats, while technically not calls per se, are a loud and distinctive part of their repertoire (listen here). Mutes are also able to make vocal sounds as well. These nasal calls (listen here and here) are not pretty but they are legitimate sounds. Because Mute Swans do not possess the long convoluted trachea of their melodious cousins, the Trumpeter and Tundra swans, their calls are relatively quiet and simple.

The best way I can think of to describe these pitiful vocal efforts is to describe them as  painfully suppressed sneezes – the kind that royalty perform when in front of their public.  As you now know, this is a very fitting analogy.

January 4, 2009

Grey Fox Passing

Filed under: Uncategorized — wykes @ 9:19 pm

In 1857 Henry David Thoreau paused to contemplate a set of wandering fox tracks crossing a frozen pond. He theorized that the footprints recorded the thought pattern of God through the wanderings of a single one of his creatures. In essence, the dusty snow enabled the animal to write a written record of his day. “The pond,” he wrote, “was his journal, and last night’s snow made a tabula rasa for him.”

Mr. Thoreau, as was his way, was obviously thinking way too much, but he has a point. Tabula rasa is fancy-speak for a “blank slate” or a blank page. The tracks on that blank page of new fallen snow are a form of written journal entry from a non-literate being. Though he probably knew the difference, Mr. Thoreau didn’t identify the exact fox species in question. When in the midst of philosophical musing, such a thing is completely irrelevant. A wombat could have made those tracks and the same conclusion could have been drawn, although the idea of a dim-witted Australian marsupial  freezing to death in the north woods of America would have presented a whole new set of questions (would the wombat have felt abandoned by God, for instance?).  This is why I am a naturalist and not a philosopher – I answer the wrong questions.

Thoreau’s fox identification choice in New England would have been between a Gray or a Red Fox. I wasn’t thinking of philosophy when my son and I spotted this set of fox tracks last week (see above) at Crosswinds Marsh. I was thinking straight identification. Wombat was immediately ruled out, but the first impression was that these were the journal entries of a Red Fox. I took a few shots, measured one of the tracks with a broken twig, and returned to the I.D. later. When faced with filling a tabula rasa of my own, in the form of a blank blog page, I re-examined the photo evidence and discovered that the paw prints were those of a Gray and not a Red Fox.

Assigning the word “Gray” as prefix to the word “Fox” in this case was a matter of scale. It is especially important to measure wild canine tracks because they can look very similar. From Timber Wolf on down to Kit Fox, there is a steady down-grading of print size although the pattern remains basically the same. Regionally, from larger to smaller, the list goes from coyote to red fox to gray fox. These particular tracks measured a hair (intentional pun) over 1.5 inches each – which places them squarely in the realm of the tiny Gray Fox. Red Fox tracks are significantly larger and start about where the largest Gray tracks leave off. In body weight and length the two species are very close, but proportionally they are quite different . The Gray fox has significantly shorter hind feet and smaller prints.

There are other considerations when fox tracking. Red foxes tend to have very hairy paws that leave very little bare pad exposed whereas Grays are less hirsute (that’s Thoreauspeak for hairy) and show more pad. Both species can partially retract their nails in a cat-like manner, so often their tracks don’t record the presence of claw marks. Gray foxes tend to hang out in thicketed or wooded areas and Reds hang out in fields, hedgerows and backyards. These were woodland prints.

You’ll note that this animal was walking at a leisurely pace. It was placing each foot into the print of the one before it. Each track was a double impression in which the smaller hind foot was superimposed upon a larger front track (see below- especially on lower right track). This manner of walking creates the typical “line of dots” pattern so common in canines. Henry David and God both knew that. Now that you know it, you are one step closer to being God-like

Because Gray Foxes are primarily nocturnal, they are rarely seen but are very common in some parts. More often than not, they reveal themselves to us daytimers as either road kills or track marks. These sleek little gray, white and chestnut colored  foxes are peculiar among the wild dog tribe because they can climb trees and will eat a wide variety of fruits.  I have a friend who regularly had one come to his backyard Mulberry tree whenever it was in fruit to feed among the branches like an over-sized squirrel.  Winter is, of course, the polar opposite of mulberry season and I suspect our little fox was patrolling for mice, small birds, or carrion.

The winds had erased the rest of  this fox’s journal writings, so we were unable to read them any further. I guess God was wiping the slate clean.

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