Purple martins are party animals; come join them
Huge numbers of purple martins are arriving in town after a busy season raising a new generation of martins on breeding grounds throughout eastern North America.
They’re coming here to take a break before flying to winter homes in southern Brazil and northwest Amazonia. Meanwhile, young birds born this year will also be meandering around the city before making their first arduous journey to South America.
At eventide, gigantic flocks of martins will suddenly appear on the horizon and then circle over trees lining parking lots at Willowbrook and Stafford shopping malls. They’ll suddenly begin spiraling down to roost in the trees while crowding into the branches and chittering to each other like crowds of people at an outdoor concert.
The causeway over Louisiana’s Lake Pontchartrain near New Orleans also hosts massive gatherings of martins.
But why do thousands of purple martins roost in trees at shopping centers, bridges and powerlines before the final trip to South America?
Martins are communal by nature, as anyone who hosts a colony of breeding martins in a martin house will tell you. It can’t be surprising that massive assemblies of migratory martins would convene in our area before flying across the Gulf of Mexico.
One thing’s for sure. Rather than remain idle at layover spots like local shopping centers, martins stay busy. They take off from their nighttime roosts at dawn and spend the day devouring late summer’s hordes of flying insects. Their rapacious insect diet fattens them, and the added fat fuels their long flight south.
Bright lights surrounding nighttime shopping center parking lots attract multitudes of flying insects. That means mar
tins wake up to a readymade insect breakfast. Martins also roost in large flocks at winter homes in Brazil, wherever they can count on an enormous supply of flying insects.
Purple martins measure about 8-inches long with about a 15-inch wingspan and represent the largest North American swallows. You can pick out adult males by their wholly iridescent purplish-blue plumage. Females and juveniles differ with grayish bellies, but males born this season may show purple splotches on their bellies.
They’ll reach Brazil by November. But males will return to Houston as early as mid-January to look for the previous year’s nesting location or to find new places.