SHREVEPORT, La. (KTAL/KMSS) – Migratory birds from across the nation are meeting up in Shreveport and throwing massive parties every day before leaving to spend winter in South America, but this nature-based pilgrimage won’t be happening in downtown Shreveport as usual.
Instead, Purple Martins have recently moved their pre-migration roost site and are now gathering by the tens of thousands at the Red River Refuge.
“There could be a hundred thousand or more Purple Martins in Shreveport now,” said Terri Jacobson, a Red River Refuge Ranger, in late July.
Jacobson said she watches them dance across the sky from her house in Shreveport on late-summer evenings.
“I’ve counted close to 2,000 just flying over my house on their way to the refuge. They just start gathering up at evening, dusk, and getting together to go to their communal roost site.”
Jacobson said many of the Purple Martins that spend late summers in northwest Louisiana have spent springs and most of the summer in other regions of North America. The birds are meeting up in the Bayou State before flying to their winter home in South America, and tens of thousands take to the skies together on late-summer evenings.
“Purple Martin Parties,” as some birdwatchers call them, happen in
late summer when groups of these little migrating birds cross the continent to gather at enormous roost sites where they feed on insects and organize into smaller groups before leaving for South America.
Jacobson said Purple Martins are arriving in Shreveport from as far away as Canada and Wisconsin, and it seems many of them are heading to the refuge.
But things haven’t always been this way.
Just a few years ago, swirling masses of Purple Martins roosted in downtown Shreveport. But they have changed the location of their Purple Martin Parties in recent years, and Jacobson said she may know the reason why they stopped roosting downtown.
“If you cut down their trees, they don’t have any place to go.”
As she talked, Jacobson was busy paying attention to her surroundings. It was nearing sunset at the RRR, and she had cordoned off a portion of her evening to observe the tens of thousands of Purple Martins that take to the skies just before dark.
“The birds start to come in as the sun sinks on the horizon,” she said. “They’ll be coming from the northeast and northwest.”
A Purple Martin neared Jacobson and RRR intern Megan Crider’s kayaks, but the bird paid little attention to the observant humans and instead focused on eating bugs.
More martins appeared, their flight patterns almost erratic as they abruptly yanked their bodies in new directions as they flew. But there was a beauty, a grace, in their quick jolts to the left or right. The tiny, feathered skydivers flipped and dipped, dove, and climbed as they ate their way through the sky and into the sun-streaked evening.
Purple Martin Parties are becoming common attractions across the nation, though the trend hasn’t fully taken off in Shreveport yet. Vendors sell purple ice creams and treats with purple sprinkles to late summer birdwatchers at other roost sites, and it’s all in celebration of the amazing voyage that is soon to come. By late spring and early summer, Purple Martins nest from Baja, California to Canada, and in winter they’re eating bugs in countries stretching from Columbia to Brazil. The days of Purple Martin Parties are a reminder of the birds’ amazing ability to travel from one continent to another.
But it’s not all fun and games when it comes to these little birds. Purple Martin numbers are down in some regions, and habitat loss isn’t the only reason why.
Purple Martin migration in a changing world
This article in Smithsonian Magazine asserts that mercury contamination in South American wintering grounds may be part of the reason why Purple Martin population numbers are falling. Heavy metals prevent the purple-hued birds from storing fat, and without the stored energy to migrate there comes a slimmer chance of survival during migration.
But others think there’s more to the story and that climate change may be posing a real threat to the species.
“All insect-eating birds here are migratory,” said Jacobson of the Red River Refuge. “If it’s too cold here they don’t have any insects to eat. They have to go south.”
But as the weather changes with the warming of the planet, how will bug populations be affected? Do hotter summers mean that Purple Martin migration dates will change one day, too?
According to one source, seventy bird species in the United States have lost two-thirds of their populations since 1970, and if statistics prove correct the United States will lose another 50% of our breeding birds in the next 50-year time period.
A University of Toronto study traced the flight of two groups of Purple Martins from South America to their homes on the east coast. They found Purple Martins do not advance their time schedules based on climate shifts in temperature—therefore temperature does not cue martin migrations. Martins move from continent to continent on certain dates because natural selection, a very slow process, allows only the birds capable of following their natural instincts to survive. But are the migratory behaviors of Purple Martins capable of advancing rapidly during times of equally rapid climate change?
Bird migrations
In the 17th century, Charles Morton believed that birds migrated to the moon and back every year. We’re still a young species ourselves, we humans. But in reality, birds don’t migrate to the moon. They migrate from place to place here on earth because it increases the odds of their survival. Migratory birds often travel on flyways, which are bird superhighways in the sky, to their winter and summer homes. But all too often, at the end of epic migratory journeys many birds return home again to find to the ecosystems their species has visited for generations have been destroyed by natural and unnatural causes.
For countless generations, bird flock movements have given some species better odds of surviving, reproducing, and passing their migratory behaviors along to their young. But changes in global temperature could mean trouble for birds that follow strict ancestral schedules in search of insects—particularly if insect populations see-saw in numbers as a result of climate change.
Jacobson said the exact place on the refuge where thousands upon thousands of martins are roosting in late summer is hard to pinpoint.
“It looks like the same numbers of birds as we had last year, but this year they’re further back,” she said. “There could be as many as a hundred thousand.”
Jon Soul, a teacher and outdoor educator in Shreveport, had the chance to see Purple Martins in their new roost location last summer.
“Last year, there was not a piece of the sky before sunset that didn’t have Martins,” he said.
Jacobson said she heard Martins are also gathering at Stoner Park and in other places.
As she watched the birds party at the refuge, Jacobson said she has been thinking of migrating, too. She’s nearing retirement and said it’s almost time to move on, but as she shared what she has loved about being an active part of
refuge life there’s a sparkle in her eyes.
“I love having the chance to see real nature, to see animals in the wild. That’s what’s cool. We used to have a log by the back deck where an
alligator hung out one summer. Last week I was a deer and her fawn. It doesn’t matter to me whether it’s an armadillo or a snake. I’m happy to see anything in the animal creation realm. It’s always exciting.”
Though she doesn’t have a retirement date yet, Jacobson said she’s starting to think about what might come next in her life.
“I don’t know where I’ll go,” she said. “But I might get an RV and start doing the RV thing, going with the birds.”
If you’re interested in helping migratory bird populations, the National Wildlife Federation says there are ways you can be bird-friendly. Keep your cats indoors and eliminate pesticides in your yard. Reduce your carbon footprint, join a group of people who are concerned about conserving bird habitats, and ask your representatives to support bird-friendly legislation.
