By: John Latimer
The month of March is often a study in contrasts. We experience days of warmth and promise, days that have us thinking about short sleeved shirts, followed by icy blasts of winter that send us back to the closet looking again for the parka. In like a lion and out like a lamb might cover the month some place well south of here. Ours may be more aptly summed as, in like a lion and a lamb followed by a meal of mutton and a nice wool sweater. Whatever the case March almost always produces two contrasting events, both suggest that winter is indeed in retreat.
March nearly always heralds the return of the robins. And March 26th is the average day of this auspicious event. In 30 years of observing their migration there have been only six years when they didn’t make it back in March. In five of those six years our tardy travelers were here in the first week of April. Last year the first robins didn’t make it back to Grand Rapids until the twentieth of the month. Though the average is the 26th the range runs from March 6th through the 20th of April. This is a remarkable span of time and serves to reinforce the notion that robins migrate based on temperature.
Compare that with the great blue heron whose return is so predictable I can with some confidence state that they will be returning to northern Minnesota within a few days of April 1st. Their average date of return is March 27th and in those same 30 years the range runs from March 17th to April 4th. In only seven of those thirty years did their return deviate from the average by greater than four days. Obviously the great blue herons are using something far more predictable than temperature to guide them back to northern Minnesota. They rely on day length or the angle of the sun to tell them when to return.
When the robins return they almost immediately begin to sing and establish territory.The first ones back are the males and if they can defend a particularly desirable piece of ground they stand a far greater chance of attracting a mate. Often times singing alone won’t do and then we will observe robins chasing one another. When even that isn’t enough to settle the dispute they may come to blows. Two males scrapping in flight, wings smashing into one another, beaks stabbing like rapiers, they attempt to drive their rival off the best ground.
Contrast this with the great blue herons that nest in colonies. Several large trees may support as many as twenty nests. These nests are perhaps two feet in diameter and often are removed from their neighbors by only a few feet. The great blue herons return peacefully to their rookery and take up residence among familiar faces, at least to them, for they all look the same to me. Arguments may ensue, but for all of that the difference between the herons that nest within feet of one another and the robins that vigorously defend a nesting territory that may encompass several hundreds of square feet they are as different as the days of March.
From the phenology notebook:
March 3, 1993 Bald eagles are returning to the north. I spotted two today, one over Pokegama Lake and the other near the nest by my house. A pair of gray jays has discovered the dog’s food and are making frequent trips to abscond with the bounty. I watched as one picked up six chunks, each the size of the tip of my little finger, and stored them in its throat before flying off to cache them. Pussy willows are beginning to open and the furry aments are shining against the darker bark.
March 11, 2006 In another tumultuous day rain falls and the sound of thunder is heard for the first time this spring. Perhaps this noise woke up the chipmunk that could be seen poking his head out from the woodpile. This is the first one of the season. Another phenologist in the Akeley, Mn. area reports seeing an otter. Redpolls are still mobbing the feeders. Spiders are getting more active in mailboxes and one was seen spinning a web.
John Latimer is well known throughout northern Minnesota for his phenology work. John appears weekly on KAXE radio in Grand Rapids, and audio and twitter archives are available here. We hope his work will be a frequent feature on MyMinnesotaWoods. This article also appeared in the Duluth Senior Journal. It is printed with the author’s permission.