Wrens

by Dennis McNair, PhD

Photo of a house wren taken by Twan Leenders

For several years, House Wrens (Troglodytes aedon) have nested in a faux polo helmet that a former owner attached to the outside wall above the deck at our condo.  The “button” (hole) at the crest of the helmet is just the right size for them, the capacity of the space apparently suits them, and the twigs they use as primary nesting materials seem to fit nicely.  They’re courageous little brown parents, flitting back and forth with caterpillars for their babies, and eventually fledging them to join the chorus that endears Chautauqua to us.   Karen and I share the deck with wrens until about the end of June and it’s ours for the rest of the summer.  They scold us loudly when we dare to come onto the deck while they’re feeding their young, but they persist.

It might seem kind of silly for me, as a biologist, to worry about those little birds.  They’re not particularly endangered - yet.  Charles Darwin made it clear that, on average, only one female of each species can survive to replace her mother, or else Earth would be overrun by that species.  (Humans – with a population of about 1.2 billion in 1859 when Darwin published his famous book and now over 8 billion - seem to be hell-bent on proving him correct.)  Still, something urges me to want “my” wrens to succeed.  They work so hard, they’re so cute, they’re brave – I anthropomorphize like crazy.  

And birds of many species are being threatened – their prey insects and plants are being killed off or made into sources of long-lived pesticides, we remove seeds by cutting off wilted flowers in our gardens to make them “neater,” bird habitat is being encroached upon or destroyed, humans have imported exotic species (House Sparrows, Starlings, House Finches, etc.) that compete with native birds for nest sites and food, the list goes on and on.  Researchers at the Cornell Lab of Ornithology estimate that the North American bird population has declined by 2.9 billion and half the world’s bird species have gone, or are going, extinct.  I haven’t heard the song of a Meadowlark (Sturnella magna) or seen a Bobolink (Dolichonyx oryzivorus) for years - birds that were quite common earlier in my life.

I believe that people will always find beauty in their world.  It may be in art or the love we feel for each other, but the greatest source of beauty in my world has always been the diversity of living things.  I never doubted that biodiversity would always be there for me to enjoy.  It finally dawned on me that things weren’t right a number of years ago, when I noticed that both the species richness and abundance of insects in the stream where I had taken my Ecology class for years was beginning to decline.  I’d never worried about depleting my world (or that stream) of “bugs” but suddenly it occurred to me that my students and I were becoming part of the problem instead of learning how to be part of the solution.  We were collecting and counting aquatic insects from a part of a healthy stream where the numbers of species and the number of specimens within each species were beginning to diminish.  The water was also becoming ever so slightly warmer year after year.  So, I started returning healthy specimens to the stream after we had identified and counted them.  However, we were only there one day per year, and the insects had to deal with changes in their environment for the other 364 days.  Their numbers continued to dwindle, so I quit taking my students there and converted my class exercise to using data from prior years.  

The major problem with that approach was that the students didn’t get to see the live creatures that had brought so much joy to me ever since I was a little boy.  (My favorite pastime when I was about 10 was turning over rock in the stream that ran near my home and watching the bugs there.  It still is.)  I also began hearing alarming reports of declines of other animals and plants, and of the disintegration of the intricately evolved biological networks that support all of us in so many ways, not just providing the beauty of life around us.  

So, I’ll continue to do what I can to support my tough, perky little wrens.  I might not be able to truly do much to directly assist them, but I can at least stop doing things that harm them.  For the month of June, the old polo helmet is theirs to use, and my wife and I will minimize our use of the deck.  Our gardens are already free of pesticides, so they’re feast for caterpillars (and, in turn, will feed the baby wrens).  There are plenty of small actions we can pursue to make life easier for wrens and others.

Since the ‘60s, one of my mantras has been, “If you’re not part of the solution, you’re part of the problem.”  These simple gestures are little enough for us to do, considering that the living world has provided such delight.  If I can’t hear Meadowlarks anymore, perhaps at least the wrens’ songs will help to swell the morning chorus and prolong it for a few more decades.