First migrants are early harbingers of spring
“Timing is everything,” some say. That’s certainly true for migratory birds. When we consider timing for these species, more than anything else we are talking about weather. Weather can mean the difference between survival and death for migrants. Wild creatures have been blessed by evolution with exceptional instincts about when to migrate, but accidents and freak events can happen to them, too.
As we begin the official season of spring this week, it is amazing how different the same period in two consecutive years can be. Much of Minnesota was free or nearly free of snow by this time last year. March of 2012 was notable for many warm temperature records over much of the state; 70 degree readings were not uncommon. There was even a tornado reported last March.
Fast-forward to this year, and Minnesota is not only experiencing below average temperatures, but a great deal of snow. It is proving to be one of those March months when the proverbial “high school tournament blizzard” expectations are being shown to be more than fiction, or an “old wives’ tale.”
I am always surprised by at least one early migratory arrival every spring. This year, during the first week of March, with ample snow everywhere, I heard the soft, almost self-conscious “coo, coo, coo” of a mourning dove when I opened the back door in the half-light of early morning to let our Labrador out for her morning duty. I stopped and listened intently, not believing my ears. But the call came again, and I heard it again the next morning.
I had not heard nor seen a dove in the neighborhood, or at a feeder, since their departure last September. They are early fall migrants, not they kind of bird that hangs on until pushed out of the state by Old Man Winter. For this reason I have little doubt that this was not a holdover dove that had failed to migrate.
Finding enough food to keep the metabolic furnace generating energy and body heat is the main concern for any early arriving migratory bird. Unlike some early arrivals, like the occasional robin, mourning doves don’t normally depend on insects and other animate things for food. For adults in particular, seeds, both wild and cultivated, make up almost their entire diet. If seeds on shrubs and trees don’t tide them over, those found in backyard feeders will do nicely. In a pinch, mourning doves will also eat the dried fruits of ornamental crabapple trees, and other domestic shrubs and trees.
As out-of-place as a mourning dove’s call seems on a snowy, below-freezing morning, it’s a welcome sound, helping us believe that the reality of spring will soon catch up to the calendar’s declaration.
One relatively early bird that must “get the worm,” is the American woodcock. This robin-sized game bird with the long, pointed bill is perfectly suited by nature for probing soft ground for earthworms. But where do those birds arriving at the end of March and the beginning of April find such fare?
The earliest woodcock arrivals tend to gravitate to places where there are seeps and springs on the edges of wet, low lying woodlands, often bordering swamp land. Here the ground thaws earlier than elsewhere, and in this softening earth the woodcock will find their first meals on their northern breeding grounds.
Land-adapted birds like the mourning dove, the woodcock, songbirds, and others, sometimes fail to survive extended periods of sub-freezing temperatures and deep snow during the transition from Winter to Spring. There are other migratory birds, however, that are very well suited to the rigors of uncertain migration weather. These are the waterfowl, the ducks and geese.
Although many ducks and geese feed on land – on crops, in particular – during certain seasons, they can find all the sustenance they need in the waters that lead them back to us from their wintering grounds. Their northward migration follows the progress of open water, first in rivers and streams, then in shallow ponds and marshlands as they thaw. There they find security and food, bide their time, and arrive hand-in-hand with genuine Spring, ready to raise the next generation.
Unlike us, wildlife pay little heed to the calendar, or to presence or absence of a shadow seen by a groundhog!