Monday, March 4, 2013

Purple Martins

     It's March in Florida:  time to put up your boxes for purple martins.  After they complete their arduous migration trip from Brazil, these birds depend entirely on human support for their survival in Florida.
     Which raises an important question.  To what extent should we be supporting populations that can't support themselves?  How much should we override Darwinian mechanics, which has functioned for millennia to keep organisms adapted to the material constraints of our planet, and when should we cave in and say, "Sorry, if you can't make it on your own, you're doomed"?
     After all, it costs something for us to take care of handicapped species.  And when it costs so much that the survival of other species might be threatened by our intervention, we have to put on the breaks, don't we?  Otherwise, we'll upset the whole "balance of nature."
     Isn't this a question that has plagued civilization for centuries?  How far should our humanism go?  It's a political question--the one about "entitlement spending."  Should those of us who work and pay taxes keep on funding those of us who don't, or can't, or won't?  How many disabled people can a population handle, before it caves in?
     It's a parental question, too.  At what point do you stop feeding and housing your grown kids, and tell them instead to get jobs, fly the coop, give you a break, make it on their own?  Aren't they duty-bound to "give back to society"?  You know you can't support them forever, because you're going to get old and die. 
     And it's a problem of thresholds in nature.  How much Spanish moss can a Live Oak handle before the deleterious effects--reduction of sunlight and an increase in wind resistance--prove fatal to the host tree?  How many fleas can a dog support before it succumbs to blood loss and histamine overload?  How many weeds will strangle your productive garden plants?  How many barnacles can a turtle tote on its shell before the extra weight causes the whole shebang to collapse?
     Thus, we arrive at the question of purple martins.
     In the south, these birds depend completely on humans to provide specific shelters for nesting, so they can lay eggs and reproduce the species.  You and I will put up purple martin boxes, situating them in wide-open areas because the birds have to swoop from far off to make a proper landing at the 2 1/8-inch entrance holes of their houses.  (The holes must be cut no bigger--or starlings and screech owls will take over--nor can they be smaller, because the pregnant martins won't fit.)  The poles on which the nesting boxes are perched must be 10 to 20 feet high, with entrance holes one inch above the floor.  The boxes have to be 30 feet from trees and buildings, to allow the birds long aerial landing strips, with owl-guards to prevent owl, hawk and crow intrusions.  In addition, the poles must be fitted with pole-guards to keep predators like snakes, raccoons and squirrels from scurrying up for a quick meal of chicks and eggs.  The boxes must have inner compartments that are five to seven inches high,  and six by six across, with four or six rooms to a house, because martins prefer to live in colonies.
     Okay, that's a lot of requirements, but we can meet them.  Except...
     Here's the tough one.  When the inevitable non-martin birds arrive to claim your purple martin boxes, you have to chase them off and kill them.  That's right, kill them!
     This means if you want purple martins in your backyard, you must be prepared to kill the house sparrows, European starlings, tree swallows, Eastern bluebirds, and great crested flycatchers who take a liking to those cute little boxes you've constructed with care.  Otherwise, the purple martins won't have a place to live, and will die off in Florida, because they can't defend their houses without help, and they can't procure their own housing--not in the southern United States.  (In the deserts of Arizona, martins live in abandoned woodpecker holes in cactuses, therefore don't need human support.)
     Okay, that's a lot to ask of a bird-friendly, nature-loving, ecologically-minded person.  It's a lot to ask of me.  I have five purple martin boxes, but I can't stomach the ultimatum endorsed by the purple martin organization, that if I'm not prepared to kill swallows and sparrows, I shouldn't put up the martin boxes at all.  The purple martin experts say I won't be doing these vulnerable birds any favors.
     Is this how the anti-entitlement politicians think?  We have to sacrifice some people, they might as well be saying, and it's not going to be the survivors, not in a survival-of-the-fittest world.  Should we let people starve, if they can't earn money to pay for their own food?  Are we to let them die of diseases we could cure, if we covered the cost?  What's the threshold of support we can manage, as a population, before we all collapse, like barnacle-laden turtles?
     Should I kill my lovely, hardy swallows and sparrows, so the purple martins can make it?      

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