North America Has Millions of Utility Markers. This Biologist Sees Millions of Birdhouses.

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Steve Barlow of Nesting Post
Wildlife biologist and Nesting Post inventor Steve Barlow stands by a utility right-of-way marker.

Wild animals around the world are running low on real estate. Even in places without lots of people, ecosystems are being altered en masse to make space for human priorities like farmland, gas fields, highways, and pipelines.

These modified habitats may be weaker, but many still host a surprising amount of wildlife. And despite the urgency of preserving big, pristine wilderness for animals that need it, conservationists are also looking for ways to help more species thrive in places claimed by people. As Florida wildlife biologist Steve Barlow argues, these places could support richer biodiversity — along with its many benefits — if our infrastructure drew a little more inspiration from the wilderness it replaced.

It's sort of like the idea of universal design, but even more universal.

And Barlow has a plan to demonstrate what he means. He invented a birdhouse that can easily be added to utility marker poles, those ubiquitous signposts that mark the right-of-way for pipelines, cables, and other underground utilities. Called Nesting Post, it's meant to restore lost habitat for certain cavity-nesting birds, and on a massive scale thanks to the posts' prevalence across North America. It wouldn't interfere with the markers' original purpose, he notes, so it should be a win for everyone.

"We've got hundreds of millions of these markers out there," Barlow says. "Why not make them more useful than just marking the right of way?"

His plan targets secondary cavity-nesting birds, species that raise their chicks in hollow trees or other nooks, yet lack the ability to create those spaces on their own, instead of relying on pre-existing cavities. It began with an epiphany in the 1990s, and after 20 years of incubating the idea, Barlow secured a U.S. patent in late 2017. If his project takes off, it could not only boost dozens of cavity-nesting species — similar to the nest-box campaign that helped bluebird populations rebound last century — but also an array of ecosystems and communities enriched by their presence.

'If you build it, they will come'

Nesting Post bird house
A prototype of the Nesting Post, designed to integrate with utility right-of-way markers. (Photo: Steve Barlow/Nesting Post)

This quest is personal for Barlow, who traces it back to his childhood in rural northern Florida. The region's wildness sparked his love of nature — "it was really a playground for an aspiring biologist, which I was by the time I was 10," he says — but its booming human population also started to worry him over time.

"I was lucky that I grew up in a very biologically diverse area," he adds. "But there is also rampant development with humans moving in, and that really made an impact on me. This habitat is being lost, and you face a reality where you're not going to stop it. People are going to move to Florida, and they're going to love Florida for the same reasons I love Florida. That reality kind of shaped my life."

At age 15, Barlow began volunteering with the Florida Fish and Wildlife Conservation Commission (FWC) and the U.S. Fish and Wildlife Service (FWS). He served five years in the U.S. Army after high school, then used the GI bill to attend college, receiving a bachelor of science in biology and chemistry, followed by a master of science from the University of Florida in environmental sciences and wildlife ecology.

Barlow's first job with the FWC involved designing and building bat houses, something that fascinated him. His father had been a builder, so he grew up with construction skills, and now he had a perfect way to use them. "It really is a passion for me," he says. "When you create a nesting or roosting structure, you're creating habitat. And when you do it to attract a specific species, and then you see them use it, to me that's almost like a miracle. It's like 'if you build it, they will come.'"

Thinking outside the nest box

The seed for Barlow's invention was planted even earlier, while he was still in college. One day in the late '90s, he was watching a pair of bluebirds nest in a hollow tree when an idea struck him: "Most of the nest boxes we build are square with dimensional lumber. And I thought, 'Why not build some round ones?'" That might help a nest box appeal to some cavity-nesting birds, he reasoned, by more closely mimicking their natural nest sites. He experimented with plastic pipes, which offered roundness as well as resistance to squirrels and woodpeckers.

"The first one I built was in 1997. The birds really took to it well, so I put up a couple of dozen of these in a few places," he says. "They were basically maintenance-free, and woodpeckers couldn't enlarge the hole as they do on a wooden house."

Barlow may not be the first person to build a round birdhouse, but that was just part one of his breakthroughs. Part two came a couple of years later. "Around 2000, I was putting some [nesting poles] up along a right of way, and it just so happened that at the same time a crew was coming through putting in fiber-optic cable," he says. "They put up a marker pole right beside one of my nesting poles, and I immediately I could see that it would be easy to incorporate a nesting cavity into one of these poles."

petroleum pipeline marker posts
Pipeline markers like these have untapped potential as bird habitat, Barlow says. (Photo: Steve Barlow/Nesting Post)

Barlow knew this was a good idea, but it wasn't his top priority at the time. He was still working on bat houses, too, developing roomier designs to host larger colonies and serve as educational spectacles for people. In 2006, he founded a company called Wildlife Integration, which specializes in community-sized bat houses for its mission of "bringing wildlife and people together in a positive way." This remains a big focus for Barlow, but his other invention also began to gnaw at him.

"To be quite honest, I sat on the idea for a while," he says. "This idea was just in the back of my head for seven or eight years, and then, there just comes a point where you're like, 'You know what, I'm just gonna do it.'"

Pole position

map of U.S. pipelines
Pipeline routes are among the rights-of-way where Nesting Posts could be used. U.S. Department of Transportation

Working with designers and engineers, Barlow developed a way to incorporate his Nesting Posts into utility markers with minimal changes. That's important for affordability, he explains, but also for preserving the markers' original purpose: warning people not to disturb sensitive underground utilities.

"We've got a design that can integrate very easily into any marker pole system, usually without replacing the actual pole," he says. "The color of the enhancer on top marks what's under there. Orange is communication, yellow is gas lines, sometimes red denotes liquid petroleum or electric. So they are color-coded, but the color doesn't really affect the use of birds. It would still have all the warnings, so it really won't interfere with the pragmatic purpose of why that marker is there."

The plan was promising enough that Barlow decided to apply for a patent, a process that took a few more years. He finally received his patent in November 2017, and now he's in talks with potential partners, including energy and communications companies as well as a manufacturer of the marker poles themselves. Nesting Posts would not represent a big expense, Barlow says, since companies are required to mark the rights-of-way for these underground assets anyway.

There's also another perk for utility companies: Nesting Posts could help boost their conservation cred, especially if they broadcast the results on the internet. "With webcams, I think that's a great opportunity to help get people involved because then anybody can see it online," Barlow says. "It's a good way for the industry to kind of demonstrate some positive things that are happening on their right-of-ways."

Many of those corridors are already good successional habitat, he adds, hosting a variety of pollinators, grassland birds, and other native wildlife. "And so by adding a nest cavity on that right-of-way, you're really adding what's the missing link in a lot of cases. It makes the habitat even more diverse."

Founding feathers

tree swallow nesting
A tree swallow feeds its chicks at Ridgefield National Wildlife Refuge in Washington state. Jason Crotty / Flickr

The Nesting Post could benefit at least 28 species of cavity-nesting birds, Barlow says, and many of those species are well-equipped to return the favor.

"All of these birds play a role in the environment. Most of them are eating insects, and so obviously that's a good thing for the most part since it helps balance the insect populations," he says. "And nesting cavities are a limiting factor for [the birds'] populations. So ecologically, this would probably be a benefit for cavity-nesting species, but also having these species around is a benefit for most farming operations. It's just a good thing to have more animals consuming insects."

The targeted bird species include:

  • Eastern bluebird
  • Mountain bluebird
  • Western bluebird
  • Black-capped chickadee
  • Boreal chickadee
  • Carolina chickadee
  • Chestnut-backed chickadee
  • Ash-throated flycatcher
  • Great crested flycatcher
  • Brown-headed nuthatch
  • Pygmy nuthatch
  • Red-breasted nuthatch
  • White-breasted nuthatch
  • Elf owl
  • Tree swallow
  • Violet-green swallow
  • Black-crested titmouse
  • Bridled titmouse
  • Juniper titmouse
  • Oak titmouse
  • Tufted titmouse
  • Lucy's warbler
  • Bewick's wren
  • Carolina wren
  • House wren
great crested flycatcher
A great crested flycatcher looks out of a nest hole in Pennsylvania. Tom Reichner / Shutterstock

Nesting Posts are an intriguing idea for bird conservation, says Jennifer McCarthey Tyrrell, bird-friendly communities coordinator for Audubon South Carolina.

"Since available nesting cavities can be a limiting factor for secondary cavity-nesting species, these houses are a great way to utilize existing structures to create more cavities," she writes via email. "I do wonder about chicks successfully fledging from the nest if they're not able to grip the slick PVC surface inside of the cavity to climb out of the nest isn't close enough to the hole for them to hop out."

It's also ideal to remove old nest material after nesting season, she notes, to help reduce the threat of parasites to nestlings. "But I think it's a great idea to help populations that are limited by cavity availability," she adds, "and have declined due to our habits of clearing dead snags for aesthetic purposes."

eastern bluebird in a tree cavity
An eastern bluebird emerges from a natural nesting cavity in a tree. Steve Byland / Shutterstock

These are good points, Barlow says, and ones he's considered, too. "I have experimented with both roughening the interior of the pipes just below the entrance hole with horizontal grooves and simply leaving them slick," he says. "Through my observations on prototype boxes are anecdotal at best, I have observed no difference between these two variables."

The depth of the nest box might be even more important, he adds. "I ensure the boxes are not too deep from the entrance hole for more than one reason. First, it would likely be too more difficult for the new nestlings to fledge if they were too deep in a box. I also believe larger depth encourages non-native house sparrow use. I prefer a box of about 5.5 to 6 inches in depth for most secondary cavity-nesting species."

elf owls
A pair of cavity-nesting elf owls share a meal in Arizona. Ed Schneider / Shutterstock

Barlow has heard many concerns that Nesting Posts might be used by house sparrows, Eurasian invaders that outcompete many North American birds. It's a valid concern, he says, but shallower nest boxes and careful siting can deter house sparrows. And in urban areas where house sparrows are unavoidable, he adds, "there is still educational value for an urban child to experience nesting birds."

As for annual cleaning, Barlow agrees it's a best practice but says it isn't vital. "I have never cleaned my prototypes in Florida and they continue to fledge birds every year since 1998. But in a best-case scenario, a local scouts group or Audubon volunteers/chapter could adopt a section of utility right of way to maintain and monitor the cavities annually. I would certainly endeavor for this type of maintenance not only to benefit the birds but also to get people involved."

Flocking together

And that brings up one of Barlow's main goals for Nesting Post. While the project is ostensibly focused on restoring lost avian habitat, it isn't just for the birds.

"This is about people as much as it is about wildlife," he says. By helping these secondary cavity-nesting birds live closer to people, and by installing webcams in Nesting Posts, he hopes to help more people — especially children — have the kind of life-changing experiences with nature that he had as a kid.

"What if there's one kid there watching that, and it sparks that kid to kind of follow in our field and do something for wildlife in their life," he says. "Every day I think about that. Not a day that goes by that I don't think about not only the wildlife using the structure but also that some person will observe that."