Column: The purple martins are back
By HOWARD LINDQUIST, Special to the Daily Globe
The purple martins are back from their long vacation in the sunny south. They leave Brazil about Feb. 15, and arrive in Minnesota in mid-April. April 15 is the day to watch for them in Worthington. But not always – the weather may alter their plans. A cold April may delay their arrival, and a warm April may bring them home a bit early.
In the spring they find their way back, first through Central America and Mexico, and then into the United States.
Once there, they tend to go directly as they can, usually to the same bird houses they had occupied last year (or the previous year). So good is their memory that is not at all uncommon for a pair to find and occupy the same nesting compartment that they had occupied the previous year. (This has been learned by banding birds.)For those who don’t know, a band with an identification number is put on one of the birds’ legs. Let us say this is done in Minnesota. When the bird then is released in Minnesota, it migrates south, carrying its ID number with it. Then, maybe someone in Brazil captures it and records its ID number. Then the bird is released. It spends maybe about half a year in Brazil before then migrating back to Minnesota to occupy the bird house that it had occupied a year ago. And its mate will, usually, be with it.Up here in Minnesota, a bird specialist will capture the bird and read and record its ID number. And by consulting his record, he will then know that the bird just in from Brazil spent the previous year in the same nesting box it has returned to. By using such opportunities, we can then soon have a history of the bird’s travels and migration habits.Twice in my life I have built martin houses, attracted a few martins and tried to maintain them.The first time I have pretty much forgotten, except to say I had too many sparrows to make it work.But I was not through yet. I had seen how the sparrows would break the martin eggs and peck the martins’ young to death.I decided to try a second time.I decided to buy a trap. I did, a cage-like box made up of wire. There was an entrance hole, which the bird entered to get at some bait on the floor of the trap. Once it got in, it could not get out because of a device that closed behind it after it got in. Adjoining the first compartment was a second compartment. A sparrow, trying this and trying that, would find the entrance to the second compartment, go in and then become unable to get out because of a similar device that closed behind it. I call the second compartment a hold compartment.When it filled up with well over 50 sparrows, it was time to empty it. To do this, I would put the trap in the car and drive out into the country. I would then take the trap out of the car, detach a panel on the bottom of the trap, and then open it and watch the birds fly out.Then I would drive back to town. I did this several times. Then I began to realize that when I released the birds out in the country, they seemed to head in the direction of town. Also, when I returned from out in the country, there seemed to be plenty of sparrows on and around the martin house. I knew then that they were flying back to the martin house as fast as I could release them out in the country.So, when I came back the last time, I stood there a minute or so and looked at them and thought, “Well, I suppose you think you are pretty smart, don’t you?” And did they look at me as if to say, “What are you going to do the next time?” And did I say, “I’ll tell you what I am going to do; I am going to drown you next time.”I had a large plastic barrel. When the sparrow trap filled up the next time, I lowered the trap into the barrel, which was almost full of water. When I knew the sparrows were dead, I pulled the trap up and emptied it. Getting all the dead birds out of the trap was a difficult and dirty task. I didn’t do it again!A person can shoot a few off the martin house with an air rifle and I did. But, there are firearm ordinances, and they don’t like air rifles. The sparrows have more time than I, so they win.When I talked with Dale Aden, he told me some about his sparrow trap. (He says it works well).The purple martin is almost entirely dependent on man for shelter and a place to raise its young. It would be nice if someone could invent or find some way to eradicate some, if not all, of the sparrows. We could give great aid to the martins and maybe even save them from extinction.How do we explain its ability to find its way such a long distance in day or night and in good weather and bad, yes, and also arrive at exactly the same place that it had been at a year previously?May I recommend a book: The Purple Martin Book, by Stokes Brown, published by Little Brown Co.
Howard Lindquist lives at Lakeview Assisted Living in Heron Lake and grew up in Douglas County.