Signs of Winter 7: Communities, Organisms and Science

Photo by D. Sillman

Photo by D. Sillman

An ecological “community” is the sum of all of the populations (i.e. all of the groupings of each species) living in an ecosystem. When you stand in the middle of an ecosystem you can see many of its species and can even appreciate their interactions and interconnections. There are, however, many organisms that evade casual observation and many kinds of important interactions that pass unnoticed.

The ecosystems here in Western Pennsylvania in which Deborah and I have spent most of our time have ecological communities that are somewhere in the middle of the worldwide continuum of complexity. They are not the bare bones systems of desert islands like we have seen in the Galapagos, nor are they the dense, almost incomprehensible species rich riots of tropical rain forests or coral reefs. Here there is almost but not quite too much to see in a given community, but there is also the luxury of finding new species or recognizing new interconnections whenever you return to a place or whenever you start to look at it in a slightly new way.

A wonderful T. S. Eliot quote comes to mind: “We shall not cease from exploration, and the end of all our exploring will be to arrive where we started and know the place for the first time.”

But what exactly is this thing we call a “community?”

Photo by D. Sillman

Photo by D. Sillman

Back in the early decades of the Twentieth Century there was a lively debate among scientists who were working in the brand new scientific discipline that they called “ecology.” One group led by Frederick Clements described plant communities (associations of plant species occurring together) as distinct and identifiable entities. Clements felt that each species contributed to the community in certain ways and every other species relied on and depended upon the other species in the community. There was a meshing, a synthesis, events full of emergent properties out of which the community became more than the sum of its parts. Clements extended these ideas to then describe how communities change over time (the process of “ecological succession”), and he described the patterns and the steps and the stages of these changes and maintained that ALL plant communities changed in this linear way and that ultimately ALL plant communities developed into stable, “climax” communities.

Clements first relied on a simile when he described his plant communities: these communities were “like” an organism. But, as my first ecology professor back at the University of Texas  put it (and he had known Clements personally), he then began to describe a plant communities as actually being organisms! The level of integration and interaction in a community was likened to the homeostatic events that enable the trillions of individual cells in each one of us to function as a distinct, singular being.

Photo by D. Sillman

Photo by D. Sillman

Now many felt that Clements had gone too far. They felt that his “community as an organism” hypothesis strayed away from science and plunged headlong into mysticism and theology. Henry Gleason was one of the most vocal opponents of Clements’ “community as an organism” idea. Gleason described plant communities as associations made up of independently striving species. He stressed that no two plant communities were exactly the same. Gleason’s ideas at first prevailed, but there is something compelling and attractive, something emotionally appealing to Clements’ more holistic framework, and his ideas regularly resurface in the developing theories of ecology.

Are we living parts of some greater organism? Are all the populations of plants and animals and bacteria and fungi around us functioning as tissues and organs in this great beast of the Earth’s biosphere? If this is science we should be able to come up with some predictions for the outcomes of a set of experiments that should occur of the hypothesis is accurate, and if these predictions don’t occur, we should reject the hypothesis. Scientific speculations are always falsifiable, after all, and many good ideas end up in the trash can of our laboratories.

If this isn’t science, though, then we don’t really have to check the ideas beyond their emotional feels and fits. Does it “feel” right to think of the Earth’s biosphere as an integrated organism? Does that idea (or “belief”) improve your quality of life? Does it make you less anxious or more confident of your place and purpose? If so, then it is quite possibly a start of a philosophy or even a theology.

Photo by D. Sillman

Photo by D. Sillman

It is really important, though, to recognize if we are talking about science or about theology, and it is really easy to let the lines blur between them. I agree with Alice Dreger (“Galileo’s Middle Finger”) that science is not just “another way of knowing” that is comparable with any other theological or philosophical system.  Science is a system not of belief (as Adam Gopnik recently asserted in a book review in the “New Yorker”) but of challenges. Science is a system that harnesses the inherent creativity of the human mind and demands slow, hard work to show that a good idea or explanation is truly possible or supportable (note that I don’t use the word “true.” Truth is too high a bar for science to attain. Truth implies an end point, and science always keeps the possibility alive that if just a little bit more information is gathered, just a slightly different perspective is developed, a scientific explanation could be completely upended).

Science has frequently been perverted by authoritarianism and autocratic declarations, it has been frequently hijacked by strong personalities and clever arguments, and it has been corrupted by dishonest researchers, but it is a system that eventually self-corrects and throws out these short cuts and partial ideas. Science’s history is one of many small steps forward, and occasional wild lurches both backwards and sideways.

So, is an ecological community a living organism or is it “like” a living organism? The line between the two ideas is very thin and very tortuously curved. I find myself jumping back and forth like the twins on the old Certs commercials: “it’s a candy! “It’s a breath mint!” “It’s an organism!” “It’s a complex, homeostatic system with a wide range of emergent properties!”

Science almost always needs more words that will fit on a bumper sticker!

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Signs of Winter 6: One Hundred Words for Snow!

(some information in this post was published in a January 23, 2014 blog)

Photo by E. S. Curtis, Wikimedia Commons

Photo by E. S. Curtis, Wikimedia Commons

Frank Boas was an anthropologist who studied and lived with the Inuit people of northern Canada in the late Nineteenth Century. He is credited (or, sometimes, blamed) for observing that the Inuits have a hundred, words for snow. His logical explanation was that dominating or important components of a culture’s environment must be reflected in the diversity of their language about those factors. And, Inuits are absolutely surrounded by snow!

I don’t know if Inuits really have that many words for snow. I also don’t know if temperate climate dwelling people, as has been alleged, have at least as many words for liquid water (think pond, lake, river, creek, rill, run, puddle, etc). I am convinced, though, that anyone who likes to ski knows quite a number of combinations of adjectives and nouns for their much beloved sliding medium and, most importantly, I am convinced that despite obvious personal inconveniences and driving difficulties, winter is greatly improved when there is snow!

Photo by A. Kljatov, Wikimedia Commons

Photo by A. Kljatov, Wikimedia Commons

Snowflakes form in very cold clouds when a starting “nucleus” (which could be a few water molecules that have randomly formed a small crystal, or a suspended clay or dust particle, or even a pollen grain) collides with a very cold water droplet. This water droplet freezes on contact with the “nucleus” and forms an ice crystal. These crystals then adhere to more water molecules in the cloud to form the larger and larger crystals which eventually become snowflakes. Once these snowflakes reach a certain size they begin to fall down through the atmosphere and can add, depending on the water content of the air masses they are falling through, more and more water molecules to their expanding crystals.

snowtypes4.jpgThe temperature and water content of the clouds and the underlying air determine the eventual size and shape of resulting snowflakes. Two snowflakes forming under identical conditions would, in spite of the old truism, be expected to be identical. The variability of conditions in any given cloud and in the surrounding air masses, though, makes forming identical snowflakes very unlikely. Kenneth Libbrecht at Caltech identifies thirty-five different types of snowflakes (great thanks to Kenneth for allowing the reprinting of his snowflake chart (from snowcyrstals.com)). Each type of snowflake is sculpted by the specific environment in which it originates.

Once on the ground the snowflakes accumulate and weather into a great variety of secondary shapes. There is powder snow (freshly fallen often low moisture snow that has not been compacted), crust snow (hard packed snow often iced together by rain), corn snow (lumpy snow made by freeze and thaw cycles), firn snow (old snow (more than a year old) that is granular but not excessively compacted), slush snow (partially melted snow often with puddles), snirt snow (snow covered with dirt and debris), watermelon snow (red colored snow due to the growth of an algae species), Yukimarimo snow (little balls of frost (seen in Antarctica), and more (maybe a hundred different kinds?)! Snowflakes can even (if they build up deeply enough and persist for long enough) compress themselves into massive systems of glacial ice.

Photo by J. Cotton, Flickr

Photo by J. Cotton, Flickr

The snow can also interact with the soil and surface litter and vegetation on which it falls to form a very interesting interface called the “subnivian space.”  The subnivia is a thin air layer found between the covering snow and the soil surface. It forms especially well when the snow layer becomes established prior to the hard freezing of the soil, and it is especially well established in complexly structured, “natural” soil-litter systems (as opposed to lawns or barren fields). Falling snow gathers on the surfaces of the irregular profile of the leaf litter and forms complex arches and domes over the dead plant materials. Heat from the unfrozen soil and also from the decomposition of the organic molecules in the leaf litter melts the contact snow layer which quickly re-freezes to form thin ice sheets which add to the structural strength and also to the insulating potential of the forming snow pack. A winter with a continuous snow cover will allow a significant and continuous subnivian space to form.

Photo by D. Sillman

Photo by D. Sillman

Within this space (which may be several millimeters to even a couple of centimeters thick) a great variety of living organisms can be found. The micro-climate of the subnivia is sufficiently mild to allow temperature sensitive invertebrates (like beetles, collembola, mites and spiders) to continue their ecological activities of decomposition and predation throughout the winter season. Many small mammals (like voles, shrews and white footed mice) use the insulated subnivian space as shelter against the harsh surface conditions and also as a safe conduit between forage sites and their burrows. Within the subnivian space they are hidden from surface dwelling mammalian and avian predators like red foxes and hawks and owls. These predators can be observed in the winter standing very still on or just above the snow surface using their keen senses of hearing rather than vision to detect these subnivian mammals. Track histories of red foxes in particular reflect the slow, quiet stalking, pausing, and explosive digging through the snow cover as the foxes’ search for their subnivian prey.

It is a rare year that we have a continuous and appreciable enough snow cover to allow the formation of a true subnivia here in the lowlands of Western Pennsylvania. I have seen, though, vole tracks worn in the grass of my front yard converging onto the seed spill area under my bird feeders after our transient snows melt. The voles use the insulating and protective cover of even a few inches of snow to help themselves, like every other species around here, to my dearly purchased black oil sunflower seeds! I hope that they get some of the corn, too!

 

 

 

 

 

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Signs of Winter 5: Remembering a Summer Hike (part 2)

Photo by D. Sillman

Photo by D. Sillman

We return to our parking spot the next day and keep on our return arc back toward Freeport Road. The yellow blazes for the trail are fresh and numerous and  lead us across the lower park road and down a narrow, muddy trail that rises up into a clearing ringed with berry-laden Tartarian honeysuckle bushes. Tartarian honeysuckle is an exotic invasive but its red and orange berries are edible and may be providing some birds with an energy-rich food source.  We cross Freeport Road with little difficulty and turn left down Altermoor Road walking past house after house with their acres of tended lawns.

Photo by D. Sillman

Photo by D. Sillman

After a block and half or so Altermoor Road turns to the north, and there is a double yellow blaze with the top mark off-set to the left indicating that the trail turns left at an old gas line sign. We follow the trail on into the woods and quickly leave the neighborhood behind. The trail is muddy and densely lined with an odd collection of herbaceous plants (which included white avens, burdock, wing stem, blackberries, black raspberries, jewel weed and enchanter’s nightshade). It is like the old field plants from the road edges and fence rows around the neighborhood have oozed their way through the opening of the trail down into the surrounding young woods. Trees are primarily black cherry, white ash and hickory. The trees get larger as we move along the trail and soon, especially when the trail rises up a few feet and becomes substantially less damp, red oak and chestnut oak become more abundant. With the appearance of the oaks, the density of the surrounding vegetation drops off greatly.

Tufted titmice and chickadees buzz over the trail and forage for insects up and down the tree branches. The black cherry trees have abundant, mostly green fruit that is just starting to show some early signs of ripening. A flock of cedar waxwings noisily flutters around the cherry branches and pecks at the, probably, still hard cherries. I have heard that the unripe black cherries are eagerly consumed by many birds and squirrels, and the waxwings seemed to be getting more than their share of this early harvest. I remember reading once about a species of baboon in Africa who were able to digest unripe, green figs. These baboons could swoop into pre-ripened fig trees and clean them out before any competitor (who could only digest the ripe figs) had a chance to get to the fruit. These baboons, according to my sketchy memory, produced powerful polysaccharide digesting enzymes which enabled them to break down the very resistant structural polysaccharides of the green figs. I wonder if the waxwings had similar digestive adaptations that enable them to get such a start of the unripe cherries? It would be a great selective advantage!

The trail takes a downward turn and suddenly becomes wet and muddy once again. The surrounding vegetation has a marshy appearance (skunk cabbage and sedges) and is enveloped in dense patches of multiflora rose. We cross a flowing creek and then head back up the trail. Slowly the ground dries once again.

Photo by D. Sillman

Photo by D. Sillman

Bright orange mushrooms are sprouting from the standing tree trunks, some of the downed wood, and, apparently, from the moist, black ground itself! A number of the black cherry trees have woodpecker holes carved into them. The size and depth of the holes (and the exuberant numbers of them) suggest that they have been made by pileated woodpeckers. Many of these holes would be perfect for cavity-nesting bird species (like bluebirds or tree swallows) to use for their nesting sites. It has been said that anything one does to increase woodpeckers in an ecosystem will also increase bluebirds!

We cross through a gate and enter what is labeled on the trail guide as the “Corral.” Signs caution every one hiking through this section to remember to secure the gates and to refrain from approaching any horses you might encounter. We saw no horses (sadly) and no fresh sign of any horses either. We are very thankful, though, that the owner of this large horse pasture allows hikers to freely cross their property!

Photo by D. Sillman

Photo by D. Sillman

We walk along the rolling pasture trail. Low spots are wet and muddy, and high spots are dry and firm. We cross through several sections of dense woods and see several exit gates uphill off to our left. Our path, though, keeps to the pasture. At once point we break out of a dense, still wooded area into a breezy, open old field. It is good to feel the cool breeze on this warm and increasingly humid day! The old field is rich with plant species. Yarrow, ox-eye daisies, bird’s foot trefoil, curly leafed dock, heal-all, and more fill up the horizontal and vertical spaces of the field.

Some chimney swifts fly overhead, chattering away gobbling up some of the mosquitoes that have been swarming around us (I hope!).

A warbler darts in and out of the dense branches of the thicket along the left side of the trail. I see flashes of yellow on its head, a black throat and chest, and dark sides with white stripes. I write down the field markings and then look it up in the field guide later: it is a black-throated, green warbler! Not especially uncommon, but a first for me! He sings a buzzy, staccato song that falls then rises into a definite “dee” ending. Great bird!

Photo by D. Sillman

Photo by D. Sillman

We leave the woods and walk past a family setting up for a cookout in their backyard.  We follow their driveway down to Alter Road and turn to the left. Alter Road is very quiet, but it is narrow and winding with some scary blind curves. We stay alert and walk quickly so that no on-coming or passing cars can surprise us. We take Alter down to Saxonburg Road and walk in a narrow bike lane (it looked like a bike lane, anyway). Large trucks race past us. The heat and exhaust fumes from the passing vehicles makes me a little lightheaded. We cross under Route 28 and then are soon able to cross the road to reach a broad, gravel shoulder. Just putting a few steps between ourselves and the hot, fume-laden road is a great relief. We see a bike rider pushing off from a crossroad during a traffic lull. He smiles and waves as he glides past us.

We turn left on the road from which the bike had emerged (Donnelville Road) and then after about 100 yards turn left again onto a gated service road that climbs up to a cell phone tower (our next hiking goal!). We pause at the gate and sit down on a soil pile to have a gorp and water break.

Photo by D. Sillman

Photo by D. Sillman

The hike up the cell tower road is steep, long and hot. We have another drink of water at the top and then work our way around the tower and along the gas pipeline. Our path crisscrosses a power line right of way for the next couple of miles, and we go from the cool, but somewhat airless shade of the woods in and out into the breezy, but sunbaked sections of open old fields under and around the tall power lines.

There are large puddles everywhere up here on top of the long ridge. Some

Photo by D. Sillman

Photo by D. Sillman

puddles in are broad low spots generated by vagaries in the soil topography while others are in deeper ruts carved out by vehicles (and ATV’s) using the soft dirt and gravel access roads. There are small cluster of air bubbles floating on many of these puddles. Closer examination shows that the air bubbles are being utilized as refuges by a substantial number of predaceous diving beetles.

There is some ominous wording in the trail guide about the way this section of trail ends. It says: the trail “descends steeply and dramatically down to Burtner Road.” Now you have to know your trail guide author to know what “steeply” and “dramatically” really mean. Some authors are prone to be a bit hysterical and hyperbolic in their use of adjectives and adverbs while others are maddeningly understated in their descriptive vocabulary. We weren’t sure to which stereotype out trail guide author leaned. We know now, though: understated to the extreme.

I am looking at the topo map of this part of the trail. We had come to a significant downward trail section that is pretty steep but still very walkable. We then went down about 80 feet in a sixteenth of a mile and had to negotiate a deep erosion gully on our way down. Out on the trail, I was not sure if this is the described ending section of the trail or not, but feel that it was not too bad.

Photo by D. Sillman

Photo by D. Sillman

In about a half a mile, though, we hit the “drama.” We go down 140 feet in a tenth of a mile and then back up 80 feet in much less than a tenth of a mile. From our perch up on top of the ridge we see our next trail section (which causes us to consider changing our summer hiking plans) and hear a hint of the passing traffic on Burtner Road. We then go down over 200 feet in less than a tenth of a mile often sliding on our rear ends to keep from careening out of control down the slope. The ridge from which we start our potential energy dispersion is 300 feet above the elevation of the road. We had done all of the “down” over almost no linear distance.

We were very happy to get into the car! We also decide to do the rest of this trail some other year!

 

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Signs of Winter 4: Remembering a Summer Hike (part 1)

(I have been saving these next two posts for the winter. Let’s all enjoy the color green for a while!)

Photo by D. Sillman

Photo by D. Sillman

The Rachael Carson Trail starts as a straight uphill climb from Freeport Road on the north edge of Harrison Hills Park. We park across the street, dodge our way across four lanes of traffic, and then walk up the gravel road/driveway that winds up toward a large cell phone tower. The sign announcing the trail is relatively new and unweathered, and the narrow road (or broad driveway?) has only a few signs of damage from the recent heavy rains. The blazes for the trail are yellow, and they are also fresh looking and clearly positioned.

The trail follows three sides of a tall, chain link fence that surrounds the cell phone tower. Signs prohibiting trespassing are prominent all along the fence line. The fence is not electrified but looks as if it could be! We keep the fence to our left and a dense mass of ecotone vegetation (dominated by poison ivy) to our right.

Photo by D. Sillman

Photo by D. Sillman

The trail heads off to the right away from the tower and dips down into a muddy rut. You have to choose to either walk in the mud or brush against the edging vegetation. Again, poison ivy is the dominant species here along with raspberry, blackberry and multiflora rose, so avoiding the urishiol and the thorns seems like a good idea. Boots and socks get soggy quickly.

Very soon, though, we break out of the dense vegetation and climb up onto the dry, open oak forest that runs along the top of the cliffs on this west side of the Allegheny River. The river far below is chocolate brown from all of the recent rain and runoff. It is also running very high and fast. Signs along the trail caution everyone to watch the drop off! We are at eye level with the vultures that frequently soar along the river.

The path follows the contours of the ridge down into gullies that are bottomed with rocky streams and then back up again. The rocks are slippery with mud and silt, and swarms of gnats and (probably) mosquitoes hover over the water.

Photo by D. Sillman

Photo by D. Sillman

Mushrooms are everywhere! Orange and red and yellow and brown, small button shapes and larger “toadstool” shapes, cones and goblets, and great, free-form lumps of tissue. The incredibly wet past month has triggered all of the soil fungi to make their mushrooms all at once!

Indian pipes are up, too. Older pipes have opened up their tops in a flower-like profusion while the newer pipes still have their dangling tight shapes. We hiked along here a week ago and only saw young

Photo by D. Sillman

Photo by D. Sillman

pipes, now we mostly see the opened shapes.

We scare a deer up from a woody hiding spot down off the trail. She goes leaping off through the dense underbrush and disappears down a hollow in series of crashes and snapping branches.

The streams driving down the steep slope to the river have cut deeply into the underlying rock. They tumble in short waterfalls over larger rocks and zig-zag around the standing arrays of smaller ones. The rocks are swept clean of any soil or silt. They are being continuously polished by the flowing water.

Along the trail oak seedlings (mostly chestnut and white oaks) grow in profusion. They are a foot or two tall with apical clusters of huge leaves.

Photo by D. Sillman

Photo by D. Sillman

In places there is an inch or two of flowing water on the trail and we have to step out into and on the surrounding vegetation. We keep a close eye out for poison ivy but have to walk where we can. We cut across the large playground and parking area and re-enter the woods. We walk over the arching, wooden foot bridge and turn right to follow the yellow blazes. After a couple of dozen yards we come to a large, black cherry tree that has fallen across the trail.

The tree has fallen in the last week. We walked this section of the trail the previous Monday and had no impediments. The violent thunderstorms of the intervening weekend probably took it down. The tree is about two feet in diameter and extends far off the trail in both directions. So, there is no choice, we either go over it or turn back. We climbed up over the first part of the tree and get ready to slide down and crawl under the second part when we notice that not only is the tree trunk on which we are perched covered with poison ivy vines but that I am holding onto a “branch” for balance that it actually a woody extension of one of the intertwined poison ivy vines that encase the entire tree. There is nothing to do by go on and we crawl down off the first trunk and under the second.

Photo by D. Sillman

Photo by D. Sillman

There are three more black cherry trees down across the trail ahead and we climb and crawl over them trying to keep from touching our faces with our possibly urishiol covered hands. Deborah walks ahead and gets a covering of itchy spider webs across her face but leaves them there.

We have about a mile more to walk and after some more mud and slipping and sliding (and a downpour of unexpected rain) finally see the car in the parking area.

(UPDATE: neither Deborah nor I got any poison ivy from our above encounter, and I really can’t explain why! Next week: Part 2 of this hike!)

 

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Signs of Winter 3: More Winter Birds

Photo by D. Sillman

Photo by D. Sillman

(some of this information was first published in a January 15, 2014 blog)

Every morning right after taking Izzy for her walk and well before my first cup of coffee I go out to fill my front yard bird feeders. I cannot leave full feeders out at night because all of the seed would be consumed by my voracious herd of white-tailed deer. Each morning I put a large scoop of black-oil sunflower seeds into each of the hopper feeders (usually just enough for a day’s feeding) and throw a couple of handfuls of peanuts and a scoop of shelled corn on the ground beneath them. I usually have to fill the heated birdbath, too (the deer have also taken to drinking out of it at night!). As I walk back into the house I look up in the branches of the tall, black locust tree behind my house and usually see one or two crows watching for their opening to come down and eat the peanuts. They start cawing and bobbing their heads when we make eye contact, and often by the time I get back inside to get the coffee started they are in the front yard, hunched over the peanuts. Soon the gray squirrels arrive to scoop up the corn and do their early morning acrobatics in sunflower seed feeders. Some mornings they even get a few peanuts that the crows have overlooked. The ground is cleared very quickly and then the feeder birds begin to arrive.

Photo by D. Sillman

Photo by D. Sillman

I want to have the feeders full first thing in the morning because the birds have had a long, cold night of intense metabolic heat generation and are in desperate need of re-fueling. Different species come into the feeders in distinct groups although their timings of arrival vary from day to day. Often the cardinals are the first to come in for their breakfast followed by the chickadees and titmice. Blue jays then push their way into the feeder perches and noisily drop down to the ground to take any nuts or corn that have been left behind. Juncos, mourning doves, white- throated, white capped and song sparrows peck around on the ground at the seed spilled from the hanging feeders, and finally the house finches swarm in and feed. Then there is usually a pause and the groups cycle back in all over again.

Photo by K.C.Agar, Flickr

Photo by K.C.Agar, Flickr

Occasionally, downy woodpeckers, red-bellied woodpeckers and northern flickers come into the feeders (and to the suet cakes if I remember to put them out). Our two Carolina wrens (who amazingly sing all winter!) also come into the feeders in between the larger, single species groups along with the white breasted and the rose breasted nuthatches. Every once and awhile some different species, often just a single individual, drops in for a snack, sticks around for a day or two, and then disappears from the yard. A few winters ago a wood thrush stayed around for several weeks. He used his long, insect grabbing bill to crack open sunflower seeds! Last year a golden-crowned kinglet showed up for Christmas (he kept to the surrounding arbor vitae bushes gleaning up and down the branches for insect larvae), and every once and a while a stray robin stops by (usually looking quite cold and confused).

Photo by A. Wolf, Wikimedia Commons

Photo by A. Wolf, Wikimedia Commons

One very interesting behavior that can be observed in the many of the winter birds away from the bounty of the yard feeders is the formation of mixed species flocks. The chickadees, titmice and downy woodpeckers in particular join together into large, complex flocks for the winter. At first glance this flocking behavior would seem to be disadvantageous to all of the species and to all of the individuals concerned. Food is in short supply in the winter, so how could the clustering of many individuals that all eat approximately the same prey items (primarily insect larvae) do anything but decrease the survival of respective species? The answer involves the facilitation of food finding and the reduction in the average individual’s energy devoted to searching for food. In the large mixed flock there is a very high probability that some flock member will find a food source (a cache of larvae under some tree bark for example). Exploitation of food sources by the entire flock with the subsequent high probability that another individual will soon find another food cache “smooths out” the boom and bust food cycle of the winter system, and thus increases the survival of a higher percentage of individuals in the mixed flock. Further, from the perspective of the downy woodpecker, flocking with the very alert and excitable chickadees and titmice also increases their awareness of incoming predators and thus adds to their chances of winter survival.

Another interesting natural behavior that was described by Aldo Leopold (author of the “Sand County Almanac”) is the positive response of chickadees to loud, explosive noises (like shot gun blasts or tree limb breaks). The chickadees swarm toward the sound very energetically (and in a mixed flock carry along the titmice and downy woodpeckers with them).  The breaking of a tree limb or the falling of a tree opens up the woody encasement that may be full of ants, ant larvae or other insect larvae. Drawn to the loud noises, these birds can rapidly exploit a suddenly available food source.

Photo by D. Sillman

Photo by D. Sillman

The main predator that regularly shows up at our yard feeders is the sharp-shinned hawk. The small, male and the larger female sharp-shins swoop across our yard at least once a week. Their success rate at securing their prey is not great, but once a month or so I find a pile of plucked feathers (usually from a dove or a cardinal) under one of their perches along the wooded edges of my field. Soon the female sharp-shin will start her mating calls (an event that Deborah videoed two years ago). I haven’t seen any immature sharp-shins around the yard or field, though, so it seems that their winter, mating “dance” has not been productive.

Photo by D. Sillman

Photo by D. Sillman

Bird songs are one of the most beautiful aspects of nature. Theories have been proposed that the first music made by humans was an attempt to recreate and control the haunting beauty of these natural songs. The fields and woods do seem empty in the winter without the whistles and melodies of our songbirds. We do hear the buzzing of the chickadees, and the rapping of the woodpeckers, the raspy whistles of the white-throated sparrows, and the occasional, rolling trills of the Carolina wrens, but the lack of full chorus singing makes the yards and the woodlots seem empty and barren.

Why don’t most of the birds sing in the winter? The answer lies in the reason for bird songs in the first place. Although many birds do use song as a mechanism of individual recognition and contact, the primary reason for song is advertisement of themselves! The male bird sings to declare his vigor, his individual territory and to attract a mate (or as many mates as possible depending on the species!). Mating is not one of the biological functions of the winter season, so most songs are left unsung until spring.

I guess that a better question might be, why do some birds sing in the winter anyway? I am going to ponder that one for a while.

 

 

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Signs of Winter 2: Super (and not so super) Moons

NASA, Wikimedia Commons

Photo by NASA, Wikimedia Commons

In mid-November our full moon was a “supermoon.” The moon was closer to the Earth than it had been in 70 years, and the truly unexpected feature of this November, 2016 full moon was that we actually see it! Cloudy skies are the rule here in Western Pennsylvania especially during our drizzly, autumn season. The November “supermoon,” though, looked like almost every other full moon that I have seen. I couldn’t say that it was bigger or brighter than normal (the 7% increase in size and the 15% increase in brightness were hard to discern).

A “supermoon” occurs when the moon is at the perigee (closest point) of its elliptical orbit around the Earth and is simultaneously in its full phase. When the moon is full at its apogee (most distant point) it will be 14% smaller and 30% less bright than the perigee “supermoon.” You would need to view these two moons side by side to really appreciate their differences, though (now THAT would be an exciting astronomical (and probably even astrological!) event! If it happened, though, it would probably be too cloudy to see it).

On average the moon is 238,000 miles away from the Earth. At the November 14, 2016 perigee, though, the moon was only 221,524 miles away from the Earth (and at its next apogee on November 27 it was 252,688 miles away. Quite a fluctuation in distance!

Photo by Joneboi, Wikimedia Commons

Photo by Joneboi, Wikimedia Commons

Ocean waters rise and fall under the gravitational tugging and pulling of the moon (and the sun!). The twice daily coastal changes in sea level (the tides) are reflective of their oscillating, gravitational influences. When the sun and the moon line up relative to Earth in space their influence on tides increases. At “new moon” the sun and the moon are on the same side of the Earth pulling together, and at “full moon” they are on opposite sides of the Earth having a great tug-of-war on the oceans. Both extremes will cause the tidal movements to be exaggerated. When the moon is at its apogee its influence is decreased and tides will not rise as high (“neap tides”) and the difference between high and low tide will be reduced. When the moon is at its perigee, though, it’s influence will increase and tides will be quite high (“spring tides”) and the differences between high and low tides expanded.

The gravity of the moon (and sun) also tugs and pulls on the Earth’s land masses. The continents themselves move (very slightly) when the gravitational forces are combined or intensified. There is even a slight increase in tectonic activity (earthquakes!) when the sun and the moon line up in their “new moon” and “full moon” configurations.

Photo by Benh Lieu Song, Wikimedia Commons

Photo by Benh Lieu Song, Wikimedia Commons

Many animals (including humans) alter their behaviors as the moon goes through its phases. Many of these described changes can be explained by the increased light of the full moon or the intensified darkness of the new moon. For example, African lions change the timing of their hunting patterns when the moon is full. The lions switch from night hunting to day hunting in response to their prey hunkering down at night to avoid exposing themselves in the over-illuminated savannahs. A consequence of this temporal shift in activity is that the lions now are more likely to encounter humans (and the incidence of lion attacks and human deaths increase!).

European badgers tend to mate during the nights of the new moon. This is because badger mating takes over an hour and a half for full completion. On nights with any moonlight at all the mating badgers (who apparently must really concentrate on the mating task before them!) are increasingly vulnerable to (and oblivious of?) predators.

Photo by J. Gentry, Public Domain Pictures

Photo by J. Gentry, Public Domain Pictures

Corals release massive clouds of sperm and eggs in conjunction with the full moon. Timing this release as total group effort makes the probability of a sperm finding a suitable egg greater and thus increases the reproductive efficiency of the entire population.

The moon, though, may also affect organisms more subtly than simply as serving as a light source. In his 2006 paper published in the on-line Polish medical journal Postepy Hig Med Dosw, M. Zimecki speculates that the gravitational influences of the moon during its waxing and waning cycles may affect the synthesis and release of both hormones and neurotransmitters which in turn alter the functioning of a variety of organ systems (including the immune, the reproductive and the cardiovascular systems) in many types of animals (including humans). In birds, the daily fluctuation in melatonin and corticosterone stops during full moon phases. In insects, the lunar cycle alters hormone synthesis and developmental processes, and in lab rats, sensory systems (especially taste) and pineal gland functions and anatomy change with the phases of the moon. The immune systems of mice are also inhibited during full moon periods.

During full moons both emergency rooms at hospitals and at veterinary clinics see increases in their patient loads. More accidents occur but there are also more cases of angina, heart attacks and strokes. Not all of these changes are attributable to just the increased light in the night sky! Brain activity changes, and more stress hormones and neuropeptides are synthesized. We all go a little “werewolf” whether we know it or not when the moon is full.

Photo by B. Rostad. Flickr

Photo by B. Rostad. Flickr

Antlions are glorious little insects that are great fun to watch and play with. These insects have larvae that often called “doodlebugs.” Doodlebugs make ingenious funnel-shaped, pitfall traps in sandy soil and hide in a tunnel at the center of the trap waiting for unsuspecting prey (especially ants!) to fall in. Doodlebugs make bigger funnels and wider, deeper holes when the moon is full. And, they even do this when they are locked away in the total darkness of a laboratory! There is something about the moon, and not just the moonlight that is affecting these doodlebugs.

There are some ominously named full moons coming up. The “Cold Moon” of December, the “Wolf Moon” of January, and the “Snow Moon” of February. They will get us through the winter until at last the “Sap Moon” of March brings the rising sugar maple sap of spring (and all of the maple syrup, too!). Hunker down everyone! We’ve got the coming holidays and then our long trek through winter!

 

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Signs of Winter 1: New (and Continuing) Birds

 

Photo by D. Sillman

Photo by D. Sillman

I have been watching my bird feeders for the “birds of winter!”

The first of these seasonal arrivals was on Saturday, October 29 (and looking back at my notebooks from previous years, this species always shows up in Apollo sometime in the last three days of October!). Scratching around in the fallen seed under my sunflower seed feeders were three northern juncos. More, I am sure will come soon. Their departure in March or April will be one of our important “signs of spring.”

Northern juncos are small, dark-colored sparrows with a long list of very descriptive common names including “dark-eyed junco,” “slate-colored junco,” “snow bird,” and “winter finch.”  It is a very common bird at almost any winter bird feeder throughout the United States, and it over-winters in almost all of the lower forty-eight states (and down into northern Mexico). The junco has an equally broad summer/breeding range across Canada and Alaska, in the mountains of the western U.S., throughout New England, and down the Appalachian Mountains into northern Georgia. In Pennsylvania, in addition to winter populations of “bird feeder” Northern Juncos, Deborah and I have observed large, summer populations of this species in the mixed hardwood forests of the Allegheny National Forest in the northwest section of the state.

Flocks of fifteen to twenty individuals form in the autumn and winter. These flocks may include several of the northern junco sub-species and also several other species of sparrows and maybe even bluebirds.  These flocks gather together thirty minutes before sunrise and disperse forty-five minutes before sunset each day. Foraging success for each individual is significantly increased when they participate in one of the groups. An individual junco tends to stay in a single foraging flock for the entire winter.

The arrival of the juncos in Western Pennsylvania has both positive and negative implications: a handsome bird has returned to grace our lawns and fields, but the cold, snowy months of winter are almost upon us!

I am keeping my eyes open this year for pine siskins! One of my biology students is writing a species paper about them for our “Birds of Pennsylvania” blog site (which will go live sometime in mid-December!). Lynn Ramage over in Ford City spotted pine siskins for her count in the Great Backyard Bird count a couple of years ago, and I could use an extra species or two on my list. I have put out a thistle feeder in my front yard to try to draw them in. We’ll see if the winter is harsh enough to drive these northern birds down into our area!

Photo by D. Sillman

Photo by D. Sillman

Also on Saturday, October 29, a flock of about thirty cedar waxwings landed in the branches of the tall black locust tree at the back of my property. Western Pennsylvania is in the year round habitat zone for waxwings, but they may migrate south if temperatures get too cold or if food supplies (berries and fruit) run low. Some flocks may fly all the way to Costa Rica or Panama to find suitable winter habitats. Always found in large flocks of thirty to one hundred birds, waxwings may form migratory flocks numbering in the thousands.  The flock that visited my

Photo by D. Sillman

Photo by D. Sillman

yard was probably after the crabapples that were still hanging on in the higher branches of crabapple trees (the deer had stretched up to eat all of the lower ones!). The birds hung around and fed for a couple of hours and then flew on. The waxwings are a wonderfully social bird with many described individual behaviors involving sharing food and other resources with the other birds of their flocks. Another of my students is writing a species page for our “Birds of Pennsylvania” blog on these gentle, gregarious birds! So watch for it in December!

Photo by D. Sillman

Photo by D. Sillman

Deborah and I went up to Harrison Hills Park on November 6 to check out our bluebird boxes and make sure that they were in good shape for the winter. Two bluebirds followed us around the High Meadow and kept a close eye on what we were doing. Both of the birds were males, although the intensity of their blue plumage was muted with the season.  Three of our boxes (last checked in late September) now had empty house wren nests in them, and one box had an empty tree swallow nest. We cleaned out the old nesting materials and, hopefully, made the boxes acceptable to the overwintering bluebirds. Most bluebirds in our region migrate at least short distances to more moderate climate zones that have a richer supply of seeds and fruit for the winter. A small percentage of our bluebirds, though, if provided suitable shelter and adequate food supplies, will spend the winter here. They run the risk of death by starvation or freezing in a severe winter, but they can reap the benefit of energy savings from eschewing migration and having the first shot at selecting local breeding territories in the spring!

Last winter Deborah and I came across a large flock of robins in the shrubby woods around the pond in Harrison Hills. The bushes and vines of this woodlot were full of berries and represented a substantial winter larder for these fruit loving birds.

Deborah has seen several bluebirds this November on her walks through the cemetery here in Apollo. They must be nesting in the line of old trees along the ridge over the river on the back edge of the cemetery property. These trees are in a very natural, untended state and are full of broken limbs and standing dead trunks. All of these potential tree holes generate an outstanding natural nesting site for any cavity nesting bird species.

Photo by D. Sillman

Photo by D. Sillman

During the first week in November the white-throated sparrow started singing just before dawn. I haven’t heard these songs since early summer! The singing became a real chorus on November 7 with three or four males all joining in together! They sang to Izzy and I while we took our early morning walk. I have read that this species sings in the winter (unlike most birds who primarily sing during mate selection or territory marking in the spring), but I have not been able to figure out why!

And finally, in big bird news from Apollo, PA: we have bald eagles! Three times in the past two weeks Deborah and I have seen bald eagles flying over our hillside. One was coming up from the Kiski River, one was racing along our ridge top heading east, and one was flying north out over the surrounding hills. This species has made an incredible come back here in Pennsylvania during the 34 years I have lived here! There are almost 300 nesting pairs of bald eagles in Pennsylvania today (compared to just 3 pairs 30 years ago!). Internet-linked nest cameras generate a continuous record of their breeding successes (and, sadly, their tragedies, too), and increasingly we are able to get glimpses of their beauty and grace as they fly over our everyday spaces!

So, the birds are active even as the temperatures drop and the snow is starting to fall. Get out and enjoy them, or at least find a nice window in your warm, dry house where you can sit back and watch the show!

 

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Signs of Fall 12: Our Other Best Friend

Taz and Friend Photo by D. Sillman

Taz and Friend
Photo by D. Sillman

People have very strong opinions about cats, and in my experience the numbers of people who have positive feelings about cats far outnumber those who have negative feelings about them. The interesting thing about these likes and dislikes, though, is that they may be the result of absolutely the same set of facts and observations! The same feature of a cat or its behavior may cause some of us to swoon with pleasure but then cause others of us to turn away in disgust. Unlike many of our political and social problems, we don’t have “different sets of facts” when it comes to cats!

So what do we know about cats?

The domestic cat (or “housecat”) was named Felis catus by Carlous Linnaeus in 1758.   This scientific name went through a number of very speculative changes over the next two and a half centuries as the biological identity of this familiar species was debated. For a while the housecat was included as a sub-species of the wild cats (Felis silvestris) of Europe (F.s. silvestris) and Africa (F.s.lybica) from which it had undoubtedly evolved. More recently, however, it was returned to its own Linnean species designation: F. catus.

African wild cat, Photo by Gurtuju, Wikimedia Commons

African wild cat, Photo by Gurtuju, Wikimedia Commons

The six (or, possibly, seven) living species of the genus Felis all trace their evolutionary lines back six or seven million years to a common, Asian ancestor.  The natural ranges of these Felis species include almost all of Africa, Europe, the Middle East and central and southern Asia. All of these cats have very similar sizes, conformations, and habits. Felis catus as a domesticated partner of humans has spread widely over most of the Earth but has retained the generalized appearance and behaviors of its closely related fellow cat species. Put a wild cat from Africa (like the one pictured above) next to a domesticated cat from Pennsylvania and they would look overwhelmingly alike.

How cats came to be domesticated is a subject of intense speculation. It seems logical to assume that humans would benefit from the ability of cats to catch and kill vermin (especially rodents), but whether this symbiosis was from an intentional act of domestication or simply the inadvertent consequence of wild cats exploiting the vermin-rich habitats created by people and then sticking around to take advantage of the weather –resistant, human constructed habitations is probably unanswerable. Wild species of Felis do display a ready tendency for at least semi-domestication and have a high tolerance toward the presence of people. So it is indeed possible that wild cats just got close to some of our ancestors and stuck around for the food and for the shelter. The nature of the human/cat symbiosis is possibly less mutualism than it is commensalism!

Photo by M. Hamilton

Binx and Mora    Photo by M. Hamilton

An often repeated story in which cats and dogs (and sometimes even children!) are compared describes a hypothetical situation in which one of these organisms is abandoned in an unfamiliar place (just pick the ecosystem: a forest, a farm, a prairie, or the seashore).  In the story, when the abandoning pet owner (or parent) subsequently (and hopefully promptly!) returns, both the dog and the child greet the returning person with great energy and affection (not to mention relief!). The abandoned cat however, in this old social myth, has taken off to explore the wild, new habitat and has begun to fend for itself and totally ignores the returning “owner.”

Now this story is much more fiction than science. I am sure that many dogs (and I can think of two that I have owned over the years) would have run out into the new, unexplored place of their abandonment with uncontrolled enthusiasm and only returned to their owners after many hours (or days) of calling and searching. I am also quite sure that some cats, if transiently abandoned somewhere, would come running to the sound of their owner’s call. I don’t even want to think about the child part of this story! Let’s just say that I think children were added to this tale by the dog-lover who first came up with this foolishness in order to add some emotional tone to the proposed dog results!

Photo by D. Sillman

Mazie      Photo by D. Sillman

Daniel Mills of the University of Lincoln in the U.K. is a widely published animal behavior expert. Mills has conducted experiments that play with the three components of the above social myth (dogs, cats, and children) and expose them each to unfamiliar surroundings and the presence of reassuring owner (or parent). Mills has found that dogs and small children demonstrably attach themselves to their owner or parent when they are placed in an unfamiliar situation. Cats, however, do not turn to their owners when placed in these same unfamiliar places. Instead, cats will focus on the surroundings and (“heartbreakingly,” according to one reporter writing about these experiments) ignore their owners.

Mills conclusions are that dogs and children “love you” and cats do not!

These experiments were featured on a BBC television special that was broadcast in 2013. I have recently searched through a number of science journal article data bases looking for the published descriptions of these studies, but, although as I said at the onset of the discussion Mills has numerous journal publications on a wide range of animal behavior topics, these experiments have not yet been described in a refereed journal.  They have been, though, widely quoted especially in on-line articles. For example in Vox on October 16, 2014 an article entitled “What Research Says about Cats: They’re Selfish, Unfeeling, Environmentally Harmful Creatures” (I guess that the reporter wanted to put his entire thesis statement in his title!) featured these experiments and repeated the social myth that I described a few paragraphs back.  The author, obviously an unbiased arbiter of the truth, went on to cite a variety of scientific sources to back up his underlying thesis that cats are evil!

Boz and MaGoo Photo by D. Sillman

Boz and MaGoo
Photo by D. Sillman

Which gets us back to our original idea: people love and people hate cats for exactly the same reasons. Domesticated cats look just like wild cats (so they are either beautiful creatures or wild animals masquerading as pets). Humans did not choose them for domestication, instead they chose us (so, they are wonderfully independent, or they are aloof and ungrateful). Cats don’t seem to notice us, they pay more attention to their surroundings than to us (so, they are curious and lively, or they are arrogant and conceited). Cats don’t miss us when we are gone or act happy when we come back (ah, they are independent and not needy like a dog, or they are sinister parasites who think that they own us!).

I take the positive side of these cat descriptions. Cats are elegant, glorious creatures full of surprises and rich rewards! They are not dogs, though. A cat has a different kind of bond with its human, and it is worth it to get to know a cat in order to assess how our co-evolution is progressing!

 

 

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Signs of Fall 11: Our Best Friends!

Kozmo (1999-2013) Photo by D. Sillman

Kozmo (1999-2013)
Photo by D. Sillman

I have wanted to write about dogs for quite a while. I am, very definitely, a “dog person,” and I go out of way to interact with dogs anywhere I might meet them. I have had over all of my 64 (soon to be 65!) years only a small, cumulative number of months when I have not had a dog of my own. I can say “Can I say ‘hello’ to your dog?” in five languages! The only thing that I might be more poly-lingual about is ordering glasses of beer or wine! There was a great flurry of evolutionary and genetic papers published this past summer about dogs: very complex stuff, but worth working through to be able to talk about our best friends.

So where did dogs come from?

Genetically there is no doubt that dogs arose from wolves. There has been, however, a great deal of controversy about where and when that dog/wolf split occurred.

Shiga 1975-1993 Photo by D. Sillman

Shiga (1975-1993)
Photo by D. Sillman

A paper published last year (June 1, 2015) in Current Biology analyzed the DNA of dogs and wolves and determined that the split between the two occurred about 30,000 years ago! This very ancient divergence challenged the prevailing notion that dogs developed as a species and bonded with humans about 10,000 years ago just as people were inventing agriculture and giving up their nomadic, hunter-gatherer life style.

This search for the temporal origin of dogs was also the topic for another research group that examined the DNA from dogs that lived 14,000 to 3,000 years ago. This group concluded that there was not just a single deep past origin of dogs. This study published in Science (June 3, 2016) showed that there were two distinct lineages of modern dogs that evolved independently from wild wolf populations. These observations (which placed the divergence of the two dog lines between 14,000 to 6,400 years ago) indicated that dogs were domesticated at two separate times and in two separate places (once in Europe and once in Asia) and that only in very recent centuries have these two lineages been recombined.

Izzy (2014-present) Photo by D. Sillman

Izzy (2014-present)
Photo by D. Sillman

So dogs have been with humans since before agriculture, and they were so important to people that they were, and this is without precedence among any of the other animal species that humans have tamed, domesticated twice! To me, this helps to explain why I feel that having a dog around is not a luxury but an absolute necessity!

So how does an organism go from being a “wolf” to being a “dog?” What is the nature of this transformation?

Wolves, like other wild animals run away from or lash out violently when approached by humans. The central cause of this fight or flight reaction is a massive release of stress hormones (especially adrenaline) that then triggers the physical behaviors. The flight distance (the distance at which an approaching human will trigger flight) or the critical distance (the distance at which protective/aggressive behaviors are triggered) that an animal exhibits vary with the animal’s experience, with its environment and also with its genetic makeup. Some individual animals are more tolerant of humans, you can get closer to these individuals and you may even be able to touch them without triggering their stress response!  These are the individuals that could be selected to build a “tame” (or “domesticated”) population! Also, young individuals of many species lack the flight or fight stress reaction to people. Possibly selection of “tamable” individuals of a species is actually the selection of individuals who retain the physiological (or emotional) characteristics of their youth!

Danny (1983-1999) Photo by D. Sillman

Danny (1983-1999)
Photo by D. Sillman

There were some very famous experiments conducted in Russia back in the 1950’s involving the domestication of another canid, the red fox (Vulpes vulpes).  Dmitri Belyaev was the director of the Central Research Laboratory of Fur Breeding in Russia. The silver fox (a variant of V. vulpes) was being bred at the laboratory and Belyaev wondered if he could select for a tamer, more easily handled animal. He had his associates evaluated the foxes in each litter for positive behaviors toward humans up to the onset of their reproductive maturity. Those individuals who were friendly to and calm around people were then allowed to breed. Within a few generations, a larger and larger percentage of the kits were “people friendly,” and soon not only the behaviors but also the physical appearances of the tamed foxes became more and more “dog-like!” The tamed foxes had floppy ears, shorter tails, and wider and shorter skulls. Their coats became curlier and took on a wider array of colors and patterns. The tame foxes also lost the distinctive “musky” smell that commonly occurs in wild foxes. The tame foxes also wagged their tails, and whined and barked like dogs!

Belyaev attributed many of these physical and physiological changes to a decline in adrenaline and other stress hormones and also to changes in neurotransmitter levels in the brain. He had “invented” a new domesticated canid! Possibly a similar selection process, carried out almost inadvertently in the frozen, Ice Age wastes of northern Europe and Asia, went on to facilitate the transition of wolves to human-loving dogs!

Izzy Photo by D. Sillman

Izzy (again)
Photo by D. Sillman

This fall there was an article in Scientific Reports (September 29) that looked at some specifics of the genetics that might have been involved in dog domestication. In this study a population of 430 laboratory raised but untrained beagles were presented devices that contained small pieces of food. Some of these devices were easily opened while others were functionally un-openable.  The researchers measured the intensity of the orientation of the dogs to human beings in their attempts to get help to open the difficult devices. Some of the dogs, frustrated by these devices turned to supervising humans with very obvious behavioral and auditory signals and “asked” for assistance in obtaining the food treat. Other dogs ignored the human supervisors completely and simply gnawed on and scratched at the food filled device.

Almost half of the dogs in this study fell into one of these two behavioral extremes. Analysis of the DNA of these dogs showed differences in gene markers found on their Chromosome #26. Approximately 30% of the dogs that actively turned to humans for help had very distinctive DNA base patterns in genes that in humans have been associated with many interactive and social behaviors! Possibly, these dogs were genetically predisposed to include humans in their social spheres (an absolute requirement for initial domestication!).

Dogs and dog perceptions have been described in several other, recent research articles. One (in Science August 30, 2016) used MRI scanners to determine how dogs’ brains process both words and emotional intonations. These researchers noted that verbal commands had to be accompanied by appropriate tones of speech in order to stimulate pleasure centers in the dogs’ brains! Another article (in The New York Times (October 10, 2016) described a dog’s sense of smell and compared the detail and importance of the odor map that a dog mentally generates as they move through the world to our own visual map of the world. Dogs create a continuous, three-dimensional matrix of olfactory sensations and orient to and interact with this scent reality in ways that we can only begin to imagine!

So, go out and do something with your dog today! If you need to, just borrow one. Your genes (and their genes) will definitely thank you!

 

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Signs of Fall 10: Return to Todd Sanctuary

Photo by D. Sillman

Photo by D. Sillman

It was Sunday morning, one day past the Ides of October. It was cloudy but already almost seventy degrees. It was a perfect day to go for a mid-Fall hike.

We wanted to get away from the broad, rails-to-trails pathways that we have been walking and biking all summer, so we fell back on our old reliable hiking site near Sarver in southeastern Butler County, the Todd Nature Reserve (formerly called “Todd Sanctuary”).

The Todd Nature Reserve is a rocky, stream crossed, 176 acre site owned and maintained by the Audubon Society of Western Pennsylvania. It has been, since Deborah and I moved to this area in 1983, one of our favorite places to hike. There are five miles of crisscrossing trails including a two mile (although it always feels longer than that!) “Loop Trail” that circles the site’s perimeter, and a number of shorter trails (with descriptive names like “Hemlock,” “Indian Pipe,” “Pond,” “Warbler,” and “Polypody”) that interconnect fern capped rock cities in densely vegetated copses with the human constructed pond (built in 1969). As you walk through Todd you go from stream beds to ridge tops and back again through young to middle-aged hemlock stands and a variety of mixed hardwood forests

Photo by D. Sillman

Photo by D. Sillman

We have had some great moments out on these trails! I remember carrying each of our children first in denim Snuggly Packs and then, as they grew, in metal framed, backpack carriers. I also remember letting them start our hikes by walking on their own and then ending up hoisting them on my shoulders after a few miles. I also remember standing quietly on a trail while a gray fox walked toward me oblivious to my presence until I said “hello, fox!” (or something equally brilliant!) and then watched him disappear into the surrounding brush. We once found a hen turkey on her nest right in the middle of one of the trails, and once we found a black bear footprint in some soft mud of a trail and spent the rest of our hike hearing imaginary bear snufflings and rustlings in the dense woods around us!

We have spotted numerous warblers in the spring and in the fall here at Todd and enjoyed the company of many garter snakes and black snakes. It seems on every hike that we come across deer standing watchful guard along the trails, too. Back in the early 1990’s, we experienced the full force of the gypsy moth population explosion along these trails (The Audubon Society chose not to use any pesticides in the reserve, so the caterpillar numbers grew unchecked!). We had to wear hats when we hiked because of continuous deluge of gypsy moth caterpillar feces as the larvae worked their way through the tree canopy and steadily defoliated the reserve’s oak trees. The infestation, though, burned itself out without human intervention, and very few oak trees were lost.

We pulled into the reserve’s gravel parking lot about 11:15 am and were surprised to see ten cars already parked there. Usually, Todd is only lightly visited and the parking area is empty. Could there be something going on today? We only saw, though, two other people out in the woods (actually they were sitting on a bench on the porch of the Naturalist’s Cabin at the start of the trails). All of the other people were well hidden out on the labyrinth of trails. When we got back to parking lot two and a half hours later, there was only one other car remaining.

There were still a few fall wildflowers blooming along the trails (white wood asters lit up the hike down to the cabin from the parking lot), but mostly the understory plants were settling in to a late fall senescence.  Color along the trails came from a thickening mat of freshly fallen leaves (splotchy red and green leaves of red maples, yellow leaves of black cherries and yellow birches). Occasionally a still green leaf fell from one the tall red oaks and arced its way, back and forth and back and forth in the light breeze, falling down through the dense branches of spice bush and multiflora rose until it landed, without a sound on top of the growing leaf cover.

Photo by D. Sillman

Photo by D. Sillman

Acorns pelted down on us steadily as we walked along. This must be a good year for red oak acorns! Next year, then, should be a good year for wild turkeys, gray squirrels, and deer! Lots of high calorie food to help them through the long winter! In some places there were so many acorns that it was hard to walk!

In the clearing between the cabin and the start of the Loop Trail (and all up the graveled trail that runs to the cabin) is a continuous and very dense stand of poison ivy. The leaves are starting to fade from their deep summer green, but they are still thick and resinous and seem to glow as they reflect and concentrate the dim sunlight. I don’t see any berries on the plants. They must have been picked clean by hungry birds!

Freshly emerged mushrooms add to the textures and colors of the exposed soil and the fallen branches and logs. We have enough recent rain to trigger a coordinated emergence of the mushrooms and their whites, reds, yellows, and browns stand out against the paler, fallen leaves. There are rustlings under the leaves, too. Everything from crickets to chipmunks to forest millipedes scrambling about on the brittle surfaces looking for food, looking for mates, or looking for a good place to wait out the winter.

The trail is, as always, rocky and difficult to walk upon. You have to keep your eyes on your feet to avoid turning an ankle or stubbing a toe. So many trails in Pennsylvania are like this! In his book “A Walk in the Woods” Bill Bryson refers to the Pennsylvania section of the Appalachian Trail as “the place where boots go to die!” You need to stop occasionally as you walk along in order to look around and keep track of trail markers and generate even a general sense of direction. While we are walking all hunched over, staring at the ground, I imagine the surrounding underbrush to be full of animals watching us with great curiosity. “What odd creatures,” they must be thinking,“ to plunge through the woods so noisily without even looking where they are going!”

Photo by D. Sillman

Photo by D. Sillman

We stopped at the pond and threw some bread to the fish (all of whom were hidden under the almost continuous cover of lily pads). Green frogs jumped at each piece of bread. The frogs just blink at the bread, though, and then swim away. We watch one green frog stalking a female dragonfly who is busily dabbing her ovipositor onto the open water near the shore. You could feel the logic of the frog: maybe the dragonfly is so focused on laying eggs that she won’t notice a clumsy, slow moving frog angling in for a leap and a grab? But just as it seemed the frog would lunge up after its meal, the dragonfly lifted up and flew away.

We spend two and a half hours wandering around the trails at Todd. There is something so peaceful about being in the woods walking on a narrow, wandering trail with only the sights of your immediate surroundings and only the sounds of your footfalls to fill your mind! We get back to the car tired but well rested, ready for whatever is coming next.

 

 

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