Friday, September 18, 2015

Migration Mysteries

Sources of wonder and worship spring from knowledge of mysteries of the distant universe. But lest we overstress the mighty wonders of astronomy discussed in the last few posts, we have decided to devote our current post to the wonderful animal residents close to our home in the northwest corner of Illinois. We trust our citation of physical and biological realities reawakens our awareness of a gracious Creator. We focus on mysteries of the complex process of seasonal migration in some animals. 

Some of our neighborhood wildlife companions are preparing for a long journey before the calendar dictates summer is over. We begin with first person observations of several colorful and unique animals in our area. In turn, we address hummingbirds, indigo buntings, bobolinks, and Monarch butterflies.

This summer has seen a proliferation of ruby-throated hummingbirds. These birds inhabit regions east of the Mississippi River. They are virtually the only hummer species in our area. For this discussion we relate mostly our own observations. Beating their wings 50+ times per second hummingbirds are able to hover, change their flight path in any direction instantly, or quickly zip from one flower pot to another in search of nectar to fuel their high energy activity. This summer I learned to wait quietly beside red salvia and geranium pots at a distance of one foot. The birds approached me and fed at close range, sometimes diverting to observe the colors of my shirt. Soft chirping accompanied the hum of their wingbeats. Some birds would pull off red salvia petals, perhaps intent on keeping their food source plants well groomed. This morning I observed a ruby-throat flying at high speed overhead in the company of two larger birds. Adult hummingbirds defend their feeding territories and chase away other birds.

Our hummers will soon be on their way to their wintering habitat in Central America. Sourcebooks suggest the males may already have departed. Next spring their northward migration will bring them back to this area, perhaps even to the same feeding stations. Migration maps reveal that first arrivals almost always return to northern Illinois during April. In 2012, our spring was unusually warm; they arrived in March that year. Hummingbird populations are increasing. We witnessed greater numbers this year. Soon the 1/8 ounce summer joy-givers will embark on their migration of approximately 3000 mi, many traveling non-stop over the Gulf of Mexico. Our admiration for them as an instance of God’s creativity has been strengthened.

Several times our posts have dealt with indigo buntings. This small iridescent blue bundle of exuberance had visited the same empty branch in a hickory tree above our garage four years running, singing mightily. This summer he did not make his appearance. Instead, we believe his descendant commandeered a neighborhood tree about one hundred feet away to offer his genetically programmed serenade. Having not heard their song for several weeks, we presume the indigos have already departed for their wintering grounds in Central America.

In my youth I discovered the joys of local farm meadows with their summer inhabitants of birds such as red-winged blackbirds and meadowlarks. One of my favorites was the black and white bobolink with a yellow patch on the back of its head. These birds have declined in numbers owing to reduction in their favorite meadow habitat. I had not seen a bobolink for many years, but for the past few summers, I have noted a male bobolink resting on a fence wire along a short stretch of narrow country road a few blocks from our home. If this was the same bird, he had repeatedly claimed the same territory several years running. In addition, he knew how to follow familiar migrational cues year after year. Bobolinks overwinter in southern South America after a one way trip of 6000 miles. If he returns next year he will have traveled 12000 mi.

With respect to the ability of long distance migratory birds to navigate precise destinations thousands of miles away from their summer and winter residences, we have studied unique systems of indigo buntings, bobolinks, and other species. The Cornell Lab of Ornithology in The Basics of Bird Migration: How, Why, and Where states, “Birds can get compass information from the sun, the stars, and by sensing the earth’s magnetic field. They also get information from the position of the setting sun and from landmarks seen during the day.” That this information can be processed and interpreted by animals without the ability to reason like human beings, is a source of wonder and an occasion to worship the Creator. Literature describing these phenomena is extensive.

Finally, in a renewal of our past summer reports on Monarch butterflies, we note with satisfaction that the summer of 2015 has seen a slight increase in Monarch sightings. Many naturalists are alarmed that one of the most spectacular natural wonders—the Monarch phenomenon—has witnessed a steady decline in the population of migratory butterflies returning to a small forest in Mexico. One article suggested the problem of diminished Mexico overwintering acreage is somewhat misleading. This year there are some encouraging signs. Locally, I have seen a number of butterflies the past few days making their way in a southwesterly direction. Last summer I did not notice any on their migratory journey. Perhaps I was not observing diligently enough. On a recent walk one monarch flew by me closely, met a bank of trees, then ascended up and over, flying higher and higher. He flew to an altitude of about 200 feet, then disappeared flying southwest. Was Mexico in sight for him?

Linked below is the first of several annual summer commentaries on the Monarch butterfly from 8/8/08. We detail some remarkable facts about the Monarch migration:

Our home in this universe, extending from the distant cosmos to our neighborhood back yard, is filled with opportunities to glorify the God of Creation. We are reminded of one of the Apostle Paul’s unusual defenses of the Christian faith before a group of pagan, polytheistic Athenians at the Areopagus (Acts 17:15-34). Paul appealed not to deep theological verities, but initially encouraged the Athenians to look for God in the physical creation. For the Greek thinkers, their innate religious sense could be affirmed. It is interesting that a recognition of God in the physical realities of creation origin and the current creation order may exemplify God’s grace. Ultimately, our young people and adults may more easily perceive the grace of God which leads to salvation through Jesus Christ (Titus 2:11).