Reflections in Nature: The true call of the wild

BILL BOWER/Sun-Gazette Correspondent Migration has begun.

On Feb. 19, my wife Mary Alice and I traveled to the state Game Commission Waterfowl Area at Middle Creek, where we saw hundreds of snow geese; however, thousands were expected to come in the next few weeks.

My diary entry on Feb. 20 was that I heard a flock of Canada geese winging north. Then, on Feb. 21, I wrote that I saw many flocks of geese heading north, with six flocks passing over at one time. The migration has begun.

By now, most of us have seen geese, ducks and mergansers heading north and perhaps a few of you have seen red-winged blackbirds and robins. These migrating birds are returning to their home ranges.

Home has been defined by ornithologists as the place or general area where a bird builds its nest and raises its young. Many North American birds (cardinal, titmouse, etc.) are sedentary, meaning they spend all year within their home ranges. Others — usually insect eaters — are migraters that leave their home ranges to winter in a warmer climate, where their food supply is available.

Our word migration comes from the Latin word migrare, which means to wander. The words emigration and immigration also come from migrare. Other words which spring from migrare are mutate, meaning to change; commute, meaning to exchange; and commuter, which is one that makes daily trips between cities and suburbs.

It was not until the 19th century that the word migration was given as the reason for the disappearance of birds at certain times of the year.

Plato wrote, “Either death is a state of nothingness and utter unconsciousness or, as men say, there is a change and migration of the soul from this world to another.”

Although we know a great deal about the migration of our birds and animals, we still have much to learn about this movement of wildlife.

Aristotle, who lived in 384 B.C. to 322 B.C. (yes, these dates are correct) wrote, “Some creatures stay put for the winter, while others move south after the autumn equinox. These species move north again after the spring equinox, this time to avoid the heat.” He also made this observation, “All creatures are fatter in migration.”

Just how astonishing are some of these migrations? Every year as the summer wanes, willow warblers weighing only a few grams will undertake a journey of 5,000 miles to escape the harsh winter weather. In comparison to man, this is equivalent of traveling 10 times the distance from the earth to the moon or 24,140,000 miles.

The arctic tern performs a migration twice yearly that takes it from one pole to the other. This is a round trip of 25,000 miles that is unequalled by any other migrant. To complete this journey, the arctic tern must fly non-stop for eight months of the year. While on this migration, it will feed by plunging into the water to capture fish.

Over its lifetime of about 25 years, an arctic tern can fly nearly three times the distance from the earth to the moon. The Arctic tern also sees more daylight than any other bird.

The most famous insect migrator is the monarch butterfly. Its life cycle is closely related to the milkweed plant.

The monarch’s migration is so predictable, with respect to direction and time of year, that towns along the monarch’s flight path celebrate their arrival with festivals. Pacific Grove, California, calls itself the “Butterfly City” because most of the monarchs west of the Mississippi River spend winters there.

The Bible makes reference to migration in Job 39:26 “Doth the hawk fly by thy wisdom and stretch her wings toward the south?”

Birds of prey do regularly fly south in autumn, especially in the Middle East. Then, in Jeremiah 8:7, “Yea, the stork in the heaven knoweth her appointed times; and the turtle dove and the crane and the swallow observe the time of their coming; but my people know not the judgement of the lord.”

Aristotle, Pliny the Elder and others have recorded that some birds disappeared at certain times of the year; however, Aristotle believed that some birds (swallows for example) hibernated.

Species of birds migrate differently. The smaller insectivorous birds usually migrate at night for large distances. They land and feed for a few days before resuming their migration. By migrating at night, they minimize predation; however, one cost for these night-time flyers is loss of sleep.

Some ornithologists believe that the birds that migrate at night could alter their quality of sleep to compensate for the loss.

Usually in late summer, after the breeding season and a molting period and just before migration, a bird’s metabolism undergoes profound changes. Migratory birds begin accumulating large amounts of fat just under the skin.

This extra fat provides energy needed for the long migration flight. Weather is one of the external influences that can cause birds to migrate. In the fall, a high pressure moving south creates ideal conditions of cool air and winds moving in a southerly direction. In the spring, a low pressure front moving north will start a wave of migrating birds to move north.

The mountain quail, which lives primarily in areas of dense cover, in the wooded foothills and mountains along our West Coast, makes the shortest migration of all birds. In the fall, these birds will congregate into family groups of up to 20 birds and make their way from their summer home in the mountains, into the sheltered valley below the snowline. Although this seasonal journey covers only distances of up to 20 miles, these quails do not fly on this migration — but travel by foot.

Many people believe birds start and end their migration on exactly the same day each year; however, they do not. Although it is said that the famous swallows of Capistrano, California, leave on Oct. 23 and return on March 19, their dates of departure and arrival have been found to vary from year to year.

A flock of Canada geese winging overhead heading to their breeding grounds is a sound that creates an excitement in me that I believe is the “true call of the wild.”