PUMA basics

• Purple Martins are the largest swallow in North America. They are in the same family as Barn Swallows and Tree Swallows.

• Adult males are the only dark-bellied swallow in NA. Females and juveniles have pale underparts.

• Purple Martins breed in North America (orange) and winter in South America (blue). Much of the eastern population migrates across the Gulf of Mexico, traveling over 10,000 miles each year.

• Migration begins after nestlings fledge. Migration begins in June and goes through mid-September, with peak in mid-August.

• They are aerial insectivores – diet consists exclusively of flying insects such as beetles, true bugs, flies, dragonflies and damselflies, leafhoppers, grasshoppers and crickets, butterflies and moths, bees and wasps, often at altitudes of at least 50m. 

• They are one of the few birds that depend on human artificial nest sites (also Chimney Swifts and Barn Swallows) such as martin boxes or gourd systems. Historically, they nested in woodpecker holes and snags but now nest in groups.

• They produce only 1 clutch of young, with an average of 3-6 eggs. Young leave the nest at 28-29 days.

• They are very vocal, with at least 11 distinct vocalizations. Listen for their bubbling chirps and creaky rattles.

• Breeding bird survey (BBS) data suggests that populations in North America are undergoing a long-term decline that has been especially evident since 1980. 

History of PUMA fall migration roosts in Nashville

• During migration, Purple Martins form large night roosts. Individual martins may use a roost for several weeks before moving on, but the roost itself lasts 8-12 weeks or longer.

• The Purple Martin Conservation Association (PMCA) detected many martins roosting in two locations in the Nashville area starting in 1996 based on NEXRAD (radar) images. 

• Since then, PUMAs have been documented consistently in the Nashville area with fluctuations in numbers. The largest roost observed was in 2020. The roost has changed locations a number of times. See Appendix A for detailed information.

Research at Nashville Metro Parks, Warner Park Nature Center (WPNC)

• Since 2000, WPNC staff have monitored the breeding success of Purple Martins at the gourd system on the nature center campus. In addition to monitoring the boxes, federally permitted researchers band the nestlings – over 700 nestlings to date. Nestlings have also been banded at Shelby Bottoms Nature Center.

• In 2021, by radio-tagging nestlings we learned PUMAs from WPNC spend about a week in their nesting area (post-fledgling) and then join the downtown roost before migrating to South America.

• In 2022, nestlings were radio-tagged at WPNC, Bells Bend Nature Center, and Ellington Agriculture Center. We learned these PUMAs also joined the Nashville migration roost. They used a large area of Middle Tennessee for their daily foraging, then returned to the roost. One radio-tagged PUMA from WPNC was detected in Costa Rica on its migration south!

• One nestling from 2022 returned to WPNC in 2023 and another was detected in Pennsylvania.

• In 2023, we have radio-tagged 25 PUMA at WPNC, Bells Bend Nature Center, and Ellington Agriculture Center and look forward to learning about their post-fledgling movements and roost behavior.

How can I help

• Purple Martins depend on artificial nests to breed, so install a gourd system. The PMCA has fabulous resources.

• They only eat insects – grow native plants and do not use pesticides! Encourage others to do the same. 

• Volunteer to educate and engage at the roost location.

• Keep the Nashville roost safe. Bird Safe Nashville

  • Visit Bird Safe Nashville to learn more

  • Contact your local representative to let them know we should welcome these extraordinary travelers by

    • Passing bird-friendly window laws

    • Restricting the use of pesticides

    • Ensuring the roost location is safe for the birds and they will not be disturbed

• Help join Nashville’s Urban Bird Treaty efforts to protect bird habitat, reduce hazards to birds, and educate the public about the benefits of birds. Email Nasyr Bey at nasyr.bey@TNC.ORG

• Contribute to the BIRD Programs research by donating to Friends of Warner Parks.

How to observe the Nashville Purple Martin Roost

• Where:  As of 5 July 2023, the Purple Martins appear to be roosting at Symphony Place, Nashville 

• When: July through early September, 15 minutes before sunset until dark

• How: The birds seem to tolerate humans but we encourage onlookers to be respectful.

  Note: European Starlings are often confused with Purple Martins, since they too travel in flocks, stage on wires and fly into a roost at night. They fly into their roosts before the martins do, usually just prior to sunset.

Resources

• Purple Martin Conservation Association at https://www.purplemartin.org/

• All About Birds at https://www.allaboutbirds.org/

• How you can help birds - https://www.3billionbirds.org/ 

• Law enforcement

  • TWRA Headquarters: R2 Office: 615-781-6622; R2 Dispatch: 615-781-6581

  • USFWS Agent: 615-736-5532

Purple Martins in the news

 https://www.nytimes.com/2020/09/07/opinion/a-150000-bird-orchestra-in-the-sky

https://www.nytimes.com/2022/04/11/opinion/nashville-symphony-bird-migration.html

https://www.audubon.org/magazine/fall-2022/this-tiny-brazilian-island-could-hold-key-purple