ASNV and Partners Install a New Purple Martin Colony at Four Mile Run

Photo: Purple Martin house volunteer team, Tina Dudley

Tina Dudley

Kurt Moser and Greg Butcher working on the winch system for raising and lowering the gourds. Photo: Tina Dudley. 

As part of Stretch Our Parks, volunteers worked with the Four Mile Run Conservatory Foundation to install a Purple Martin colony at the end of February in Alexandria’s Four Mile Run Park. ASNV purchased the needed equipment thanks to fundraising efforts by the Nextgen Birders for Conservation group, an initiative by ASNV to cultivate the next generation of birders and wildlife stewards. 

The raised structure, depicted above with only one gourd, is now finished and has all 12 gourds installed. Blockers are in place to discourage nest stealing before the Purple Martins return to Four Mile Run in the next month or so. Photo: Tina Dudley. 

Purple martins are our largest swallows - beautiful, acrobatic birds that swoop and dive, eating flying insects that hover over the water. They are secondary cavity nesters—unlike woodpeckers, they do not excavate their own nest cavities. Instead, they use existing cavities, either naturally occurring or created by other animals. Traditionally they used old woodpecker holes or natural cavities in dead trees or on cliff or rock ledges. But thousands of years ago, people began providing man-made housing for the Purple Martins in the form of dried, hollow gourds. Over time, the birds nested successfully in these man-made homes. The availability of those hollow gourd nests, paired with the decline of natural cavities resulting from development, led to a complete behavior shift in the eastern species.

Andreana Lin, Kurt Moser, Greg Butcher, Jacob Roberts and Luke High pose with the gourds after assembling Purple Martin balconies on the gourds. Photo: Tina Dudley. 

Four Mile Run is a 9.4-mile-long stream that starts near Interstate 66, at Gordon Avenue in Fairfax County, and proceeds southeast through Falls Church to Arlington County. Most of the stretch is parkland and is paralleled by two paved non-motorized multi-use trails, the Washington & Old Dominion Trail and the Four Mile Run Trail. You can find the new colony on a peninsula that juts out into the stream. It’s conveniently sited across from the observation deck on the Arlington side of Four Mile Run and is at least 40 feet from the nearby trees. See the location below if you’d like to visit to check it out in person. 

Map showing the location of the new Purple Martin colony at Four Mile Run

A special thank you to Kurt Moser from Four Mile Run Conservancy Foundation who finished the installation of the gourds after additional drilling was needed off-site. 

We are hopeful that Purple Martins will take up occupancy in the colony this year. If so, we will be looking for volunteers to help with weekly monitoring checks to collect citizen science data on the nests, in accordance with recommendations by the Purple Martin Conservation Association. This is a great opportunity for those interested in seeing young birds up close and learning about how to be a Purple Martin landlord. If you are interested in helping, please contact Meg Oakley for more information. 

Join the Fun this Spring and Summer and Monitor Breeding Birds with NestWatch

Photo: Purple Martin Nestlings, Deidra Bryant

Deidra Bryant

With the season of baby birds now here, it is important for ornithologists to collect data on nest construction, successful nestling development, and overall care from adults. To do this, nest boxes must be constructed and mounted properly. If scientists are reusing a nest box from the previous season, the box needs to be cleaned out so birds can have a nice place to call home. You can build and set up nest boxes at your residence too and casually watch as birds fly in and out. However, you can also take a more involved and scientific approach to observing and understanding the reproductive biology of native birds nationwide via the Cornell Lab of Ornithology NestWatch program. 

Purple Martin nestlings, Deidra Bryant

NestWatch is an interactive online program that allows you to view tips on how to build and install your own nest box, and upload your personal nest monitoring metrics to an archived database that aids in bird conservation. You can also read blog posts, annual reports from previous years (NestWatch Digest), and scientific publications regarding nesting ecology and breeding bird populations. You will have to make a free account with Cornell Lab to get the full experience though. Viewing the website is possible on multiple devices (via tablet, personal computer, smartphone) but I find that using a tablet or PC works best since the images and infographics are much larger and the text is easier to read. There are also some helpful documents that you may want to download and print from your personal computer like the Nest Check Data Sheet for when you’re in the field and don’t want to bring your electronics outside. 

Deidra Bryant monitoring Purple Martin nests

Getting started is very easy. When you open the webpage you will immediately see “How To Participate.” Although it’s tempting to just select a bird on the homepage and initiate a nest plan, the first and most important step is to read the Code of Conduct and take the short quiz to get certified. The test is a safety measure used to minimize risk of accidentally damaging the nest, causing parental desertion, and attracting predators to the nest. The test also communicates planning tips so you know what to expect and how to quickly, accurately, and safely record useful data. 

So, you have your nest box(es) set up in the proper manner using the provided species specific structure plans, followed tips on how to deter predators, and placed it/them in its respective habitat…what do you do now? You wait. You monitor your nest every 3-4 days and wait for someone to safely lay their eggs in the shelter you made for them. Use this time to familiarize yourself with how to enter data online using the multiple data entry tutorial videos from the LEARN tab on the website. If you’re lucky and get a resident, make sure you remember the Code of Conduct and keep your paper records safe from damage such as water stains, page tears, bird excrement, etc. Those notes need to be digitized after each visit or after a nesting attempt is complete. In graduate school I surveyed over 300 Purple Martin (Progne subis) nests in at least 10 sites in South Central Pennsylvania. I had several paper datasheets similar to the one used in NestWatch for every site and used them to excruciatingly transfer numerous results to an Excel spreadsheet. 

Purple Martin on nest, Deidra Bryant

As I write about Cornell University’s NestWatch program I think of the kind Amish families I met when I monitored their martin birdhouses for research. Young children and their parents would come outside and tell me what other interesting birds they saw flying around, and sometimes their neighbors would join in and observe if I brought my drone to geofence the site. One empty nester (no pun intended) would always ask me to sit with her on her porch and chat about gardening tips and her engaged sons while we watched the martins fly in and out of their nest gourds with bees in their beaks. One family had binders with laminated data sheets that were over a decade old! I also remember how I’d often come home with gifted bags of fruit and veggies from their orchard and/or farm when it was time to leave. It was such a wonderful experience with so many people and I’ll never forget it. Although we currently live in an age where our community often communicates through a screen, I think where NestWatch succeeds is employing citizen science to not only  bring us together to achieve something bigger than ourselves individually, but also to step outside and talk to friends and neighbors about how nest monitoring can be a memorable experience.

May Bird of the Month

Photo: Purple Martins, John James Audubon

Purple Martins Thrive in Northern Virginia with a Little Help from Their Neighbors

Jessica Bigger

Mike Bishop grew up on a beautiful large piece of property in Spotsylvania, Virginia. During his childhood, Bishop and his father would put up nest houses for bluebirds and monitor the nests each year. After successfully attracting bluebirds to his family’s land, Bishop decided to put up a Purple Martin (Progne subis) house to see what would happen. After a year or two several Purple Martins had taken up residence. “We got three colonies,” said Bishop. 

Today, Bishop and a group of volunteers monitor around 22 Purple Martin houses throughout Northern Virginia. After retiring, Bishop decided to get back into building special nest boxes for Purple Martins that reduce infestation by starlings and sparrows; an improved design from J.L. Wade’s aluminum version, which was quite prone to starling and sparrow infestation. 

He built his first Purple Martin nest box in one of Westfield High School’s athletic fields. It took three years to attract Purple Martins to that location but now Westfield High School has three established colonies. Bishop founded the Northern Virginia Purple Martin Initiative in 2015 to increase and strengthen the Purple Martin population in the area. The organization not only builds and monitors nest boxes for Purple Martins, but volunteers also build houses for other cavity-nesting species, including woodpeckers, Chimney Swifts, Great Crested Flycatchers, the Tufted Titmouse, chickadees, wrens, Eastern Bluebirds and Tree Swallows. 

Because of Bishop and many other bird advocates across the country, the Purple Martin’s population is stable and of low conservation concern. Purple Martins nest in open fields, usually near a water source. Since most of their habitat provides little nesting opportunity, this species has always depended on human assistance. People have been providing homes for Purple Martins for centuries, beginning with Native Americans, who used to build nest cavities out of gourds. They created a symbiotic relationship with the birds. In exchange for providing nesting habitat for the Purple Martins, the birds would warn the Native Americans of owls and hawks hunting nearby. 

Purple Martins not only warn residents about birds of prey, they also keep the insect population at bay, which protects their gardens and makes relaxing outside a bit more enjoyable.

Purple Martins are social species. They love hanging out near people, and enjoy visiting other colonies nearby. Reston National Golf Course has a nest box near Links Pond that houses one colony of five birds. Reston resident and Fairfax County Coordinator for the Virginia Bluebird Society's nest box monitoring program, Helaine Krob, lives on the golf course and monitors the nests.“ Yesterday, we saw 12 of them up in the air flying around together. Swooping and chatting and calling. So, there is a visiting colony and after they hang out, they head home. Our colony visits another colony in the evening, and around 8:30 pm they will all return to the apt house,” explained Krob.

There are a variety of insects Purple Martins will forage for: beetles, flies, dragonflies, damselflies, leafhoppers, grasshoppers, crickets, butterflies, moths, wasps, bees, caddisflies, spiders, cicadas, termites and mayflies. They will also hunt for insects at a much higher altitude than swallows. To help them digest the insect exoskeletons, Purple Martins will eat small amounts of gravel. Some nest watchers leave crushed eggshells, which also aids in digestion.

In Northern Virginia, Purple Martins generally arrive at the end of March. Each pair raises one brood per breeding season. Last year the Reston National Golf Course Colony raised three young. At the end of August, they make the 3000-mile journey down to the Amazon Basin in South America to overwinter, and then make the 3000-mile trip back to North America the following breeding season. 

If you want to get involved in citizen science visit the Northern Virginia Purple Martin Initiative Facebook Page or the Purple Martin Conservation Association.

Sources:

https://www.youtube.com/watch?v=NDLu-aaVIjY&t=634s

https://www.allaboutbirds.org/guide/Purple_Martin/overview