Home Sweet Bridge
Purple Martin’s of the Outer Banks
Come late June, the skies at sunset around the William B. Umstead bridge begin to transform into a moving landscape dotted with about 100,000 of North America’s largest swallows. The birds stake out their place along this one-mile span of bridge on the north end of Roanoke Island, calling it home for just a short time. And while they gather the strength for the 2,600-mile journey to their South American wintering grounds, their winged presence draws hundreds of visitors eager to get a glimpse of this purple martin pit stop.
“Seeing them arrive to their nest boxes not only is a sure sign that spring is here, but their loyalty to a nesting site and a mate, and their reliance on people, bring an overwhelmingly reassuring quality to the whole phenomenon,” says Michael Gery, chair of the Coastal Carolina Purple Martin Society (CCPMS).
“Experiencing purple martins reminds us that nature is not only beautiful and uplifting, but also is mysterious and progresses by its own rules and evolution. No one who sees it ever forgets the sight and sound of 100,000 martins swirling and playing during sunset, then settling in at our roost for the night.”
For a few months out of every year for the past four decades, with peak numbers in mid-July through mid-August, these birds hunker down on the Outer Banks. While here, one of the bridges that connects the mainland to Roanoke Island is their shelter at night. But come sunrise, they descend on the abundant marshlands to feast on mosquitoes and other favorite purple martin treats.
Sunset flight, though, is the time when purple martins really put on their show. The sky coverage is so significant that the event can be picked up by Doppler radar.
In perfect synchronicity with the sinking sun, the birds return to their roost under the bridge, creating a sight that lures onlookers from far and wide. Their aerial acrobatics challenges even the best fireworks.
But when it’s time to go – and the birds are the only ones who know when that time comes – they’re gone. They go as quickly as they came.
“They stay until they are strong enough to journey to South America in late summer,” Gery said. “They seem to sense, some years, an approaching rough weather system and time their departure accordingly.”
While they are here, though, they are ours to enjoy and protect.
Visitors can experience the wonders of the purple martin by participating in a free bird-watching session or taking a sunset cruise on the Crystal Dawn, which provides an eco-tour departing from Pirate’s Cove in Manteo. Hosted by the CCPMS, the cruise runs four nights a week during the height of the season.
The society also offers sunset talks on the “Bebop” multi-purpose pier, and during the winter it arranges a workshop for landlords and prospective landlords on how to manage a martin colony in the region. (The Bebop multi-use pier is at the west entrance to the William B. Umstead bridge.)
According to the society, there were an average of about 1,650 viewers at sunset in one night during the 2011 season. In addition, approximately 220 people visit the site by boat on each trip chartered by the CCPMS.
When to Go
“The roost is active from late June through mid-September, but peak time is mid-July through mid-August,” said Gery. “Families of martins from a 30-mile radius come to this roost. We have counted about 100,000 birds at the height of the roosting period.”
The best time to see the purple martins is 30 minutes before official sunset and the best viewing spot is on the northwest side of the road. It is advisable to park on the state Department of Transportation right-of-way and stand near the foot of the bridge.
Visitors should keep in mind that high winds could prolong the purple martins’ roosting activity as it interferes with their ability to land on the perching structures under the bridge. Medium to strong winds provide the perfect backdrop to a fantastic martin show, while calm skies and low wind will result in the birds roosting much more quickly.
Depending on weather conditions, the birds may roost far from land (so bring your binoculars) or right near the shore and appear to be flying all around you.
DID YOU KNOW?
• Purple martins get their name from the male’s iridescent purple sheen over its black coat.
• The swallows are impressive aerial acrobats, making them fun to watch in flight.
• Purple martins are very social birds, nesting in colonies and chattering among themselves both day and night.
• Purple martins are geographically loyal and return to the same nesting site year after year.
• Nestlings depend on their parents for 26 to 32 days until ready to fly. When the young are strong enough, the local adults accompany their offspring to the roost at the Manns Harbor Bridge.
Experts suggest looking to the west along the shoreline, as purple martins follow the waterways to reach the bridge. When darkness falls, the martins fly lower with the latecomers using the water as a guide.
“Each and every night will be different, but every night is going to be beautiful when you are visiting the birds,” the website reads.
A Society to Protect
The Coastal Carolina Purple Martin Society was formed in 2006 to advocate for the protection of the purple martins at this popular roost between Roanoke Island and Manns Harbor. It is believed that thousands of martins have been killed at the roost every year, but thanks to a collaboration of private and public forces, signs and flashing lights have been added to warn motorists to use caution along the bridge.
The society worked with local and state officials in 2007 to have warning lights, an enforced 25 mph speed limit, and signs active during the roosting period, at dawn and dusk, when the birds leave and return to the bridge.
What makes the bridge and region so attractive for the martins are the abundant insects available to them due to nearby agricultural fields, national wildlife refuges, and the coastal plain’s wetlands. Alligator River National Wildlife Refuge, just a short distance from the bridge, hosts moist soil and flooded fields, the perfect breeding ground for the martin’s favorite food – flying insects.
Where to Go
The William B. Umstead bridge is the selected roost for these amazing flyers. Its plentiful support structures, I-beam girders, and cables give them plenty of options to roost; not to mention, they prefer to roost over water where they will encounter far fewer predators than roosting over land.
Martin “landlords” throughout the coastal plain of North Carolina provide nesting quarters for the birds in everything from hallowed out gourds to elaborate martin condos. The martins return to these houses every year for nesting season and once the young have fledged, the martins meet at the Umstead Bridge, also widely known locally as the Old Manns Harbor Bridge.
The more heavily used Virginia Dare Memorial Bridge to the south has diverted much of the vehicular traffic from the old bridge, which has reduced the number of martin deaths during their roosting season. Gery encourages the public to visit the roost in the summer and learn how to start and manage a colony. ♦
Rolling Out the Welcome Mat for Purple Martins
East of the Rocky Mountains, purple martins depend entirely on humans for their nesting sites. It is believed that no bird in the United States relies on man as much as the purple martin. Following are a few tips for encouraging them to set up house in your own backyard year after year:
• According to the Purple Martin Conservation Association, the idea that purple martins eat huge quantities of mosquitos is a myth used by purple martin house manufacturers to sell their product. Purple martins do eat flying insects, but that includes everything from beetles and flies to midges, mosquitoes, mayflies, and butterflies.
• Martins are picky about their housing. Place houses in the middle of the most open spot available, preferably about 30 to 120 feet away from human housing. There should be no trees taller than the martin housing within at least 40 feet. The farther away from trees the birdhouse is, the better.
• Martin houses should be painted white, but trim can be any color. The white reflects the sun’s heat and keeps nestlings cooler.
• Prospective martin landlords should not open their housing any earlier than four weeks after the first martins are scheduled to return to their area. However, if a neighbor within a mile has established colonies, you can open your house as soon as your neighbors’ first birds return.