100_1321I had not meant too stay in the woods for so long.  The last light of day was gone and the evening twilight was lingering in the forest and would remain until the blackened skies under a new moon silenced even the vaguest whisp of light on the horizon.  Prior to sundown I had been hearing a noise not too far off in distance.  I suspected it was a large buck. It sounded like he was thrashing shrubs and saplings with his antlers; a common behavior at this time of year as the bucks shed the velvet from their antlers.  Hoping to catch a glimpse of the deer I stayed put.  I tried calling him by mimicking a competitor, but had no luck in bringing him within view. 

Now the night was settling in and I had about a two mile northerly trek through the woods to get back home.  I had come to my present location via an indirect route using some old logging trails and woods roads.  It was about twice the distance as a straight line back to my home.  I decided to take the short route on the way back.  I knew I would have some ledges to climb, a stream to cross, and some bushwhacking through some densely forested areas, all a challenge in the dark, but the temptation of a short journey home after a long day in the woods sounded inviting.

Travelling alone in the woods at night can be intimidating to even the experienced explorer.  I knew I had to use great caution and take few risks.  There would be two distinct and necessary elements for a safe journey home.. The first would be to let my instincts guide me.  In my experience that means letting go of rational thought and letting your primitive mind take over.  When the primitive mind is in full gear travelling through the forest in pitch darkness is an instinctual rather than a sensual experience.  You have to trust your instincts to help guide you around physical objects, dangerous obstacles, and serious pitfalls.  It is a skill that I believe all humans have but also a skill that goes largely untapped and is severely under utilized.  The second element necessary for a safe journey back would be an accurate and direct route to my homestead.  I had no compass or GPS with me, so my trip back would be guided by my personal knowledge of these woods and a little directional help from the starry heavens above. 

I surveyed the sky and looked for the stars.  The thick tree cover gave my only glimpses of the starry night.   I remembered an area nearby that had been devastated by the ice storm of last winter.  There the canopy was open and I could survey the night sky. 

Arriving at my new location several hundred yards from my starting point I looked to the sky.  I quickly located Ursa Major, also know as the big dipper, which has two stars on the end of the cup that line up and point to the north star also know as Polaris.  I then located the north star, a rather ordinary sun in the distant heavens fortunately located within a hollow space in the sky that makes it very recognizable.   To be sure, I then located Ursa Minor also known as the little dipper.  The last star in the handle of the dipper is the north star.  This confirmed my earlier findings and I was on my way home. 

Before I set off I take a moment to ponder Polaris, the star that guides me on this night.  What I am seeing is the image of a time long since gone.  The light that now shines in the sky was emitted from this heavenly body 430 years ago. Travelling at a speed of 186,000 miles per second it has just reached earth.  I am seeing the past in the present. I am seeing the star as it existed forty years before the Pilgrims landed at Plymouth Rock.   It is our one opportunity to see the relationship between space and time.  It is our one opportunity to have even the most miniscule understanding of time really not being a linear series of events.  I am awed by the concept.

As I set out through the dark forest with only my light adjusted eyes to guide me I heard the distant honking of geese.  High in the sky, way beyond anything that I could possibly see, scores of Canada geese were traveling by night in search of their winter quarters.  I stopped and listened to their musical travel and wondered where they were bound.  Only they knew the answer to that question.

Bird migration has fascinated humans for centuries.  It is a complex behavior that has evolved over centuries, each bird species having their own set of behaviors to accomplish this great feat.  One of the curious theories of bird migration is that milleniums ago there were birds that stayed close to home and birds that wandered for food.  The birds that wandered for food were more successful on two fronts; they were healthier and more successful breeders.  Over time these populations had the greater chance of survival and, in that way, migratory behavior in birds was born.

Different types of birds also migrate at different altitudes.  Of course, weather events, physical obstacles such as mountain ranges, and even human influences such as air travel can impact the height at which they travel.  Generally songbirds migrate between 2,500 and 5,000 feet above sea level; ducks and geese travel between 5,000 and 8,000 feet above sea level, migrating seabirds and shorebirds fly in the vicinity of 10,000 feet above sea level, as do raptors like eagles, hawks, and vultures, and the bar headed goose, champion of altitude flights, migrates over the Himalaya’s at 30,000 feet above sea level where the air is very, very thin.

Some birds travel only a few hundred miles (or less) to find a winter food supply. Many song birds travel to Central America. The champion of bird migration is the arctic tern that travels 18,600 miles each way to arctic and subarctic environments; a tremendous distance for any type of animal!

Birds, like humans, have different social preferences.  Some birds migrate in huge flocks numbering in the tens of thousands.  Other species, like the Great Blue Heron, migrate alone or in small family groups. 

Of the many species of migrating birds there are those that choose to travel primarily at night and those that choose to travel primarily during the day light hours.  Most migrating hawks and raptors travel during the day.  They use warming air currents that rise during the day to help them along their journey.  Canada geese and many songbirds are examples of birds that prefer to conduct their migration during the darker hours of the night.  Their travel at night allows them to gather food during the daylight hours and replenish their energy supplies.

Perhaps the greatest mystery of bird migration is how they find their way to a certain destination, often using the exact route every year.  Although this behavior is not fully understood there seems to be several different abilities that help migrating birds find their way home going both in southerly and northerly directions.  The first is a “sun compass”.  Birds that travel primarily by day utilize the sun’s position in the sky to orient themselves.  They seem to be able to do this very accurately.  In other words they are capable of using the sun to some degree of precision when it comes to finding their way home. The second is a “star compass”.  Birds migrating long distances primarily at night seem to use the interspatial relationship between constellations, rather than the position of individual stars, to orient themselves and help them travel in very accurate directions on their way to a destination.  Ornithological experiments have shown that on cloudy nights migrating birds are less apt to travel long distances and when they do they frequently get disoriented.  The third way migrating birds can assess direction is using a “magnetic compass”.  Many birds seem to augment their directions by tapping into an ability to sense the earth’s magnetism.  Measurements of this ability by bird experts have determined that this ability seems to augment a bird’s ability to find its way in cloudy conditions.  It seems to be considerably weaker in some species.  The fourth way a bird finds its way to a long distance determination seems to be using a “biological map”.  This seems to be comprised of a magnetic memory component where a bird actually assesses it longitude and latitude using magnetism relative to its current position and a sensory memory where the birds recall specific smells, sights, and sounds to help them hone in on a target.

 All of these strategies are miracles of evolution and eloquent representations of natural selection.

As I climb over the last hill I must traverse a narrow pass between two outcropped ledges.  My hands search for sturdy grips on which I can depend to pull my body along the dark, steep incline.  Finally at the top, I stop to look at the sky.  A few clouds obscure the heavenly view to the east and the forest canopy covers the sky to the north.  I turn to the southern sky and find the constellations Sagittarius and Scorpius as a way of orienting myself.  I turn and face north in the direction of my homestead.  The final leg of my journey is through open woods and down a relatively gentle slope. 

As I set off I think about a warm fire and hot cup of soup.  Above me another flock of geese navigating through the abyss of night honk wildly high as they journey in a southern direction while I travel north.  We are both heading towards a destination.  I am closing in on my target. They have a long, long way to go.

 Originally written for the Heath Herald in September of 2009



  • Sandy

    What an interesting read! I didn’t know about the bird migration route elvevations.

  • bill

    Thanks for reading Sandy, there is still much to learn about bird migration, especially for particular species. Birds are such wonderful creatures. Simple, elegant, and faithful to a purpose we likely don’t fully understand.

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