As the sun sets on Erie's summer season, one congregation is just beginning its journey.

A couple weeks back, First Warning Weather meteorologist A.J. Mastrangelo noticed a few peculiar, expanding circles on radar. With a simple Google search, he was able to find out that these are likely Purple Martins.

Joe Siegrist, president and CEO of the Purple Martin Conservation Association, explains.

"They all leave at the same time, and they're just going out to live their lives and feed as much as they can," said Siegrist. "The radar, as it sweeps through, just cuts across section of that expanding sphere. That's when you see these rings on the weather radar that looks like fireworks going off. They're an animal that feeds on the wing; they only eat flying insects, so it doesn't matter really where they go. They don't have to go to a cornfield to eat off the ground or something; they just go."

It was not something Mastrangelo noticed before on radar. So what were these birds doing in the region?

"It's a fascinating phenomenon that these birds do just prior to their migrations south to the Amazon for the winter," said Siegrist. "They breed up here in North America and over winter down in South America. It can last up to a month or so."

While the routes were being observed across the region, one place that had not seen any was right here in Erie.

"As we had our very own roost right here in Presque Isle Bay, they started searching for a new place last year," said Siegrist. "There really wasn't much of a roost in our region. Then, this year, we haven't really detected one on radar just yet."

The following morning after interviewing Siegrist, Mastrangelo took a look at the radar, and there they were. Thousands of Purple Martins returned to their historical roots among the cattails of Presque Isle Bay.

"Purple Martins are a unique species of bird in that they 100% rely on people providing nest boxes for them to breed," said Siegrist. "At the Purple Martin Conservation Association, we're dedicated completely to the conservation of these birds, both through scientific research to look at the causes of the population decline that we've been seeing. We've actually lost a third of all Purple Martins in the last 50 years, but also getting the word out to people that you can save the species by simply putting up a Purple Martin house in your backyard if you want to help."

More information from the Purple Martin Conservation Association is available here.