I am happy to post the following contribution from a colleague. Thanks, Bill.
by William C. Scharf
It’s early on a clear, sunny morning in mid-April. Lake Michigan is unusually calm and the water looks smooth as glass. Hold on a second, it is glass! That’s a common result in the spring, when waves are absent and temperature drops to freezing overnight. The aluminum outboard starts cutting through the nearly inch-thick skim ice. I throttle back because I’m frightened. There seems a real possibility that a planing boat could lift itself right on over the surface of the thin ice. That could spell some sort of disaster!
An imagined news report says, “16 foot aluminum puck with airborne, roaring outboard, skimming along ice, hits weak spot, then noses in on impact and slips under ice. Body found trapped beneath ice.”
Better to slow down. The sound of ice cracking is like breaking plate glass windows, and I wonder, could really sharp ice sheets puncture an aluminum boat? Directly behind the boat are room-sized, jagged, transparent sheets sticking out of the water at various angles, and as I look further back a black path is cut in the ice. It’s very easy to see where I opened-up the motor (straight black line) and, where I got worried (the many course corrections cause zig-zags).
Why am I doing this? It’s herring gull nesting season. I’m heading for Bellows Island, sometimes called Gull Island. There, I have permission from the island’s owners, the Leelanau Conservancy, to continue my long-term studies begun college field trips over thirty years ago. It started by studying the non-verbal communications systems of herring gulls proposed by Nobel Laureate, Niko Tinbergen. Now devoid of trees, and with the ruins of an old house, it is the gulls that are the essence of this place. That is sight, smell, and sound.
Generations of students will recall Tinbergen with his thick Dutch accent proclaiming, as he strikes an offensive clenched fist pose, “When I do this, you know exactly what I mean.” He did that to show that certain signals have universal meaning. His interpretations of gull sign language are still widely accepted as definitive communication among vertebrates, and his conclusions also have applications to human behaviors. For example, smiling expresses a friendly attitude universally accepted among humans. Or, a crying baby reveals discomfort and elicits maternal behavior. We instinctively understand these signals, and so too, the gulls have also evolved their own precise set of instinctive signals. The only way to study these is in a place like Bellows Island.