Tiny Travelers -- Fall Warbler Migration
The annual fall bird migrations are underway. For highly visible species, like mourning doves and blue-winged teal, the passage is hard to miss. But there is also another mass migration currently in progress that will, unfortunately, go largely undetected by most Iowans. That migration is the southbound flight of the warblers.
As any sharp-shinned hawk will tell you; fall warblers come in many flavors. During the past several days, we've seen American redstarts, mourning, Connecticut, prairie, magnolia, and Wilson's warblers --- all observed within a single small patch of dogwood.
Denizens of deep shaded woodlands and thick understory, warblers are as secretive as they are beautiful. Many species travel only at night using the stars, constellations, the moon and magnetic fields to faithfully guide them to ancient and far away wintering grounds. Daylight hours are spent busily refueling on protein rich insects. Migration exacts a heavy physical toll on these tiny travelers and water is always a big draw for fall warblers. During the past week, I've seen up to four warbler species simultaneously bathing or drinking from my backyard bird bath.
Hyper active to a fault, warblers never stop moving for more than a second or two. Getting a good look at one presents a unique challenge; while obtaining any kind of usable photo represents the ultimate exercise in frustration.
Final Thought: "No fortuitous concourse of elements working blindly through any number of millions of years could quite account for why warblers are so beautiful. No mechanistic theory, even bolstered by mutations, has ever quite answered for the colors of the cerulean warbler, or the vespers of the woodthrush, or the swan song, or --- goose music."
Aldo Leopold, from A Sand County Almanac