Purple martin parties return to Houston

Grab your binoculars — and umbrellas. Purple martins are here.

The big picture: The large swallows — identified by their indigo feathers and long, tapered wings — spend each summer in the Houston area to roost and feed on insects to fuel up before their long journey to South America.

• And where there are purple martins, there's a parking lot packed with visitors ready for a show.

How it works: After eating insects all day, thousands of purple martins will make a swirling pattern in the air as they head to their homes for the night, causing the live oak branches to droop under their weight.

• As the sun begins to set, large flocks fill the sky, creating a dark, swirling cloud as they make their way to the trees to roost. This captivating display typically lasts about 45 minutes.

Driving the news: Houston Audubon is hosting watch parties on Aug. 17, Aug. 24 and Sept. 7 in Willowbrook and Stafford where bird experts and enthusiasts will be available to answer questions.

Fun fact: Purple martins like roosting in urban areas, away from predators, hence the locations near malls, per Amber Leung, a nature programs manager with Houston Audubon.

Flashback: Last year, the birds left Houston early, likely due to the heat, the drought, and the trimming of the live oaks they roosted on.

• Beryl did not impact the purple martins, Leung says. They hunkered down and showed up on the weather radar as normal a couple of days after the storm struck.

If you go: Roosts can be found in Stafford at the Fountains shopping area near the Old Navy parking lot and around Willowbrook Mall near Highway 249 and Gessner.

• You can RSVP for the watch parties, and Houston Audubon will provide the exact location details closer to the events, as the exact roosting site may change.

Pro tip: Park away from the trees, and bring some napkins just in case you get a lucky dropping.

The bottom line: It's always a spectacular show with the purple martins around.

• "While they're with us, we just really highly encourage people to just come and check out this marvel of nature with us or any old evening," Leung says.