ATHENS, La. (KTAL/KMSS) – Einstein proved time is relative, and anyone living in Louisiana knows this. Our seasons mingle like colors in a Jackson Pollock painting.
Birders here actually look at the seasons based on migration, and the end of January and beginning of February means only one thing: SPRING! Other people may be in seasonal denial, but birders and Purple Martins (Progne subis) know what’s up.
Purple Martins have been migrating between the Amazon Basin and the US for a long time, and they’re the very first of the feathered migrants to show up along the Gulf Coast at the end of January.
Many people refer to the first martins in their area’s colonies as “scouts” and insist they somehow cue the other martin family members to return. This is a myth. The truth is that, like many migratory bird species, Purple Martins exhibit impressively high rates of “site fidelity,” or returning to the same location for a specific purpose like breeding.
Those first returnees have nothing to do with the rest of the martins returning home again. By about Valentine’s Day, a few will reach the KTAL viewing area, but most will still be somewhere between 50 or 60 miles inland from the Louisiana coast, stretching east into Southern Georgia or somewhere in Florida.
By summer, North America’s largest swallow species will have spread itself from the Great Plains to the East Coast, minus the Appalachians, and they’ll even be in South Central Canada, the West Coast, and parts of the American Southwest. But by this time, the birds that first arrived in February and March will have finished nesting and begun their return to South America.
“Fall” for Purple Martins in northwest Louisiana starts as early as late May. Peter Yaukey, a birder and Biology professor in New Orleans, annually surveys two Purple Martin roosts on the Lake Pontchartrain Causeway.
Yaukey notes that the roosts peak about the first of July, and in 2015 he estimated 20,000 martins using one roost and another 250,000 using the other, making the bridge an important staging area for the Purple Martins before they leave the US and return to South America.
Peak fall migration for martins in the rest of North America runs through September, and pretty much every Purple Martin is out of here by October.
Many Americans love Purple Martins, evidenced by all the housing we provide for them. Mostly, it’s because of all the mosquitos they eat. Except, and pay attention here, they actually don’t eat mosquitos at all. It’s a myth.
The first step in debunking this bird myth is to consider the basics of the mosquito and the Purple Martin. To wit, when are mosquitos active? At night. When are Purple Martins active? During the day. And where are mosquitos generally found? Down low, kinda near the ground. Where do Purple Martins eat? Way up high; on average, higher than other swallows, often around 150 meters high, according to www.birdsoftheworld.org.
But surely, with soooooo many mosquitos, they eat some, right? Nnnnnope.
According to www.birdsoftheworld.org, a 1967 study in Kansas showed that Purple Martin stomach contents had traces of 57 insect families; 14 more insect families were added to that list from a study in Alberta in 1978. But based on a 1968 article published in The Auk, birdsoftheworld.org writes there is “no credible evidence this species routinely eats any mosquitos” despite their consuming such a wide array of insects.
So, where did this myth come from?
In 1966, a businessman in Illinois named J. L. Wade published a tract on Purple Martins and claimed that each one ate about 2000 mosquitos every day, but he had absolutely no evidence for it. He was said to have even studied stomach contents and still found no evidence, but he still doubled down on this very public lie.
Wade owned a business called Trio Manufacturing, which made TV antennas and poles. But according to the Chicago Tribune, in 1962, he began constructing Purple Martin houses out of the aluminum that he used in his business and put them on the poles he manufactured, soon creating a new market for Purple Martin houses.
He stopped making and selling antennas, changed the business name to Nature House, published the aforementioned false claims, and eventually made a small fortune. He finally sold the business in 2006, less than a year before his death in 2007 at the age of 94.
You’ve heard of the now decades-old Purple Martin house craze? J. L. Wade was literally the source of it and was referred to as the “P. T. Barnum of the bird world.” Which is cool, but I’d much prefer to be the “Ryan Reynolds of the bird world.” Just me? Mmk.
Despite the nasty commercial side of the myth, Wade’s success as a huckster did help the Purple Martin population and still continues to do so. At the time he began selling the houses, the martins were believed to be declining in number due to habitat loss. But at this time, they are listed as a species of “least concern,” in part because they have so many nesting sites, nearly all of which are provided for them by humans – who of course still have mosquitos and most of whom still continue to believe the myth.
Dillon is the former President of the Louisiana Ornithological Society, a regional reviewer for Cornell University’s www.ebird.org, a member of the Louisiana Bird Records Committee, on the Board of Directors of the Briarwood Caroline Dormon Nature Preserve, he’s an English Literature teacher at Minden High School, and he’s and the founder of the Minden High School Nature Club.
Dillon has also been busy writing his way into the hearts and minds of KTALNews.com readers. As one of our most popular guest contributors, he shares his extensive knowledge of recognizing our region’s birds.