PURPLE MARTINS LIVE OUT WEST!
I have an early memory of being in bed with some childhood illness. My mother was reading to me from an old book. There was a short story about a young boy who built a Purple Martin house. The book was old and tattered. My parents weren’t readers. My mother’s favorite store was called “The Salvage Store,” where the proprietor sold merchandise he had bought from stores that had gone out of business or been salvaged from wrecks during transport. I suspect the book was from that source and cost something on the order of a nickel. It is interesting to me that I remember the incident because it shows my early interest in birds.
Purple Martins are our largest swallow—approximately 1.5 times bigger than the more common varieties. Our neighbors, in the small Illinois town in which I was raised, had a Purple Martin house. Most everyone is familiar with the large apartment-style birdhouses usually mounted on poles.
I looked forward to the return of the Martins in the spring and sympathized with the neighbors’ antipathy toward house sparrows and starlings. Both would take over every apartment in the Martin house if they could. It was always a contest to see whether the neighbor, who was elderly, could keep enough compartments open for the Purple Martins. (Stopping Starlings and House Sparrows meant repeated lowering of the nestbox to clean them out.)
One year I built my own birdhouse and put it on a post in our yard. Purple Martins began going in and out. I was excited. But, then they were chased off by House Sparrows. Perhaps, that explains my still-present enmity toward House Sparrows—I even want to see their name changed (http://www.gjsentinel.com/blogs/birds_and_more/entry/whats-in-a-name-a-modest-proposal).
I took care of those particular house sparrows. I snuck out late one evening and taped the hole shut in order to murder whichever adult was present. I am surprised at myself when I recall that cold-blooded act. I really wanted to watch the Martins nest in my birdhouse.
Purple Martins are considered among the most beneficial of birds. The oft-quoted statistic is that each can consume 2000 mosquitos per day. That might be true if they only ate mosquitos, but they eat many other insects, especially flies, and often like to nest near water where they can consume dragonflies and other large insects.
The elderly neighbor died, and eventually I moved to Arizona and then Western Colorado. I probably hadn’t seen a Purple Martin in decades. Then some years ago, a birding friend took a position where he was monitoring colony nesters. One of those “colony nesters” was Purple Martins. Once I began to look for them, I realized they were reasonably common—in the right locations—and the right habitat.
That “right location” is highly-localized: within about 50 miles of the town of Rifle in aspen groves at elevations of 7,500 to 9,000 feet. Scattered populations may also be found throughout southwest Colorado. The Eastern slopes of Grand Mesa have several colonies as does the Uncompahgre Plateau. The “right habitat” is edges of old growth aspen. They nest in holes originally excavated by woodpeckers—chiefly Northern Flickers. Unfortunately, a lot of old growth aspen has been dying. Climate change, such as drought that may be hastening turnover in old-growth aspen, may be a significant threat. At one Purple Martin colony I’ve been watching, I observed that when the large, live trees died, the Martins abandoned the site, even though their former nest trees were still standing.
Our Western Purple Martins, while appearing very similar to those I grew up with, have slightly different vocalizations, and don’t use apartment house nestboxes. Some preliminary DNA testing suggests they may be a different species. At least, they are on their way to becoming one—if they survive. Colorado’s entire population has been estimated as no more than a few hundred breeding pairs. We are fortunate to have them so near Grand Junction.
In researching this article, I found there has been some success using individual nest boxes placed in a colony setting in some other Western States. Unfortunately, unlike tree swallows and violet-green swallows which readily use nest boxes only 6 feet or so aboveground (http://www.gjsentinel.com/blogs/birds_and_more/entry/swallow-tales-tailsa-lesson-in-jizz), Martin houses need to be 25ft high, and it is suggested they be cleaned every year. Mounting nest boxes 25ft up in dead aspen is a discouraging proposition. Let’s hope we can hang on to enough habitat for this beautiful bird to survive.
This post provided by Nic Korte, Grand Valley Audubon Society. Send questions/comments to firstname.lastname@example.org. To learn more and to participate in the activities of Grand Valley Audubon, please see audubongv.org and “like” us on Facebook!]