EXPLORING NATURE: SPRING MIGRATION

Spring migration is underway and new birds are arriving after over-wintering in Central and South America.

At one time, people had no idea that birds migrated with the seasons. In the 1700s and 1800s, folks had all sorts of theories about what happened to departing birds. Some figured they hibernated in lake and pond mud. Others postulated they flew to the moon in winter.

One of the first concrete indicators that birds migrated between continents came in 1822. German villagers shot down a white stork and discovered it was impaled by a thin tribal spear made of African wood.

Called the “arrow stork,” this bird led people to consider the possibility that birds might indeed migrate over very long distances.

Ornithologists at one time could only track this migration by sight and, sometimes, by sound, as they listened to flight calls in the night. One expert counted 3,800 migrant bird calls in one September night.

In recent times, birds were found to show up on radar used in weather forecasts and people could track their paths as they flew, mostly at night, from one locale to another.

Closer to home, I had a male blackchinned hummer which showed up like clockwork every March 17, for about eight years straight. This year, it did not show up — but a ruby-throated hummer did show up on April 2. I hope it, too, will return on a regular annual basis. But only time will tell.

Meanwhile, a new space-based wildlife tracking system called Icarus has begun operation with receivers placed on the International Space Station.

We’ve come a long way from looking for birds in mud or on the moon.