Sniffing Out Invasive Species

In Hawai'i, working dogs put their noses to the ground to aid conservationists.

ON AN EARLY, OVERCAST morning in Hawai’i, Kyoko Johnson parked her white truck at the Hau’ula Loop trailhead on Oahu, lowered the tailgate, and unfolded a step that reached halfway to the ground. Solo, a seven-year-old yellow lab, dutifully stepped down. Wearing a vest and GPS collar, Solo wasn’t there for a casual hike. He was prepped for a morning of work.

Photo of conservation dog
Kyoko Johnson and her 7-year-old yellow lab, Solo, survey a Hawai’i hiking trail looking for invasive weeds. Photo by Alexander Deedy.

Solo is a conservation detection dog. He’s trained to aid in conservation work by sniffing out several species of plants and animals, including that morning’s target: devil weed, an invasive plant that grows in dense thickets and chokes out native flora.

As soon as Johnson unleashed Solo on the trail, the working dog bounded off, zigzagging through the foliage as Johnson walked along the trail. Solo instinctually worked the wind, sweeping 10 or 20 yards off trail to catch any scents blowing his way. Dogs have up to 300 million olfactory receptors in their noses compared to our six million, and the part of their brain that analyzes smell is about 40 times greater, proportionally, than ours.

As Solo sniffed, Johnson scanned with her eyes. “Whenever he goes off trail I’m watching constantly, because it might be something,” she said.

Together, the duo make a powerful tool more effective than either working alone.

JOHNSON STARTED TRAINING detection dogs in 2008 after discovering that her golden retriever, Luka, preferred nose work to swimming or chasing balls. Around that time, Johnson met a biologist working on a nearby wind farm who wondered if dogs could help locate endangered seabirds and bats that were being killed by the turbines. Johnson and the biologist ran some trials and discovered that teams with dogs were indeed more effective at locating birds than people searching on their own.

That work led to another project. Wildlife refuges in Hawai’i were experiencing increasingly frequent die-offs caused by avian botulism, a fatal disease putting endemic waterfowl like the Hawaiian duck and Laysan teal, both endangered, at high risk. Birds contract the disease by eating food contaminated with the bacteria Clostridium botulinum, spread throughout the food chain by the maggots that feed on infected bird carcasses. To mitigate the spread, refuge managers use teams of people to scout the wetlands for dead waterfowl. But the work can be time intensive in Hawai’i’s dense tropical foliage, and small teams have trouble keeping up when deaths spike.

Michelle Reynolds, a biologist at Hanalei National Wildlife Refuge, thought trained handlers and canines might be more effective at sniffing out dead birds, so she recruited Johnson and Solo to help test her theory in a pilot study on the refuge. The results showed promise, suggesting that dogs in fact eased the tedious process.

It was at Hanalei that Johnson was struck by the passion of conservationists doing their best to safeguard Hawai’i, despite daunting tasks and limited budgets. She wanted to continue to use dogs to help.

IN RECENT DECADES, dogs have become an increasingly prevalent tool in conservation biology. Ecologists in Japan increasingly look to dogs to detect invasive species, while others in Australia employ them in koala conservation. The United States is home to numerous organizations that enlist detection dogs for conservation work. Conservation Canines, a program housed at the University of Washington, pairs dogs with researchers to find orca scat. Montana-based Working Dogs for Conservation uses dogs and handlers to sniff out poachers in parts of Zambia and Central Asia fighting wildlife crime. And dogs from Australia to the United States help identify honey bee colonies infested with pests and diseases.

As the world’s most remote island archipelago, Hawai’i has an incredibly high rate of endemism. But threats like climate change, habitat degradation, and invasive species push some of the state’s rare species closer to extinction.

To help position dogs as an asset to protecting Hawai’i’s plants and animals, Johnson officially launched Conservation Dogs of Hawai’i at the beginning of 2019. Since then, the nonprofit has been applying to work with state and federal environmental agencies to determine where detection dogs might be an effective tool for the government. One potential project she’s applied for includes surveying Johnston Atoll with a dog to determine if areas have been cleared of invasive yellow crazy ants, which pose a threat to seabirds, particularly chicks. Another involves searching out rosy wolfsnails, a predator of endemic Hawaiian snails.

Photo of conservation dog
Johnson gives Solo a water break during the search. Photo by Alexander Deedy.

When possible, Johnson also aims to team up with scientists from other states and countries who have experience with detection dogs to guide the Hawai’i projects. At the 2019 Hawai’i Conservation Conference, for example, Johnson organized a symposium with presentations by detection dog researchers from Florida, New Zealand, and Taiwan. But there aren’t many environmental dog experts. “In conservation dog work it’s hard to find other people and lots of data [relevant to] exactly what you’re doing, because everything’s new and always changing,” Johnson said.

Plus, despite the fact that dogs are becoming more prevalent in the conservation world, some scientists and agencies are still resistant to the idea. Lisa Kamae, a board member for Conservation Dogs of Hawai’i, explained that part of the goal of the nonprofit is to make people in Hawaii recognize dogs as a valuable conservation tool.

“If we could stop [invasive species] or at least stem the flow, why not?” Kamae said. “And you’re doing something great with your dog at the same time.”

In addition to these projects, Conservation Dogs of Hawai’i is building a network of volunteers who want to do something important and fun with their pets. Roberta Bitzer, one of the volunteers in training, said she first got interested in nose work as a way to keep her Belgian Malinois, Qana, happy. Bitzer also has a background in environmental sciences, so to her pairing nose work with conservation seemed like a dream. “It’s a way that I can give back to the island that I call home,” Bitzer said.

When Johnson first started training volunteers, she contacted the Oahu Invasive Species Committee (OISC) to determine which alien plant the dogs should target. They settled on devil weed, an odorous plant that isn’t yet widespread on Oahu but can often be found near hiking trails easily accessible to volunteers and their dogs. OISC doesn’t have enough resources to send teams to investigate every reported devil weed sighting, so they started sending notifications to Johnson to allow her dog teams to make a pass.

“It’s helpful to have as many resources as possible because when you want to eradicate something the whole key is to catch it earlier,” said OISC spokeswoman Erin Bishop. “So if we could add another tool to detect things, that could help us.” The Conservation Dogs of Hawai’i team shadowed OISC workers several times to learn proper protocol for removing devil weed, including burning seeds to prevent further spread. Johnson also shares her findings with OISC.

BACK AT HAU’ULA Loop Trail, Johnson and Solo passed the area where devil weed had been reported twice without finding anything. If devil weed were along the trail, Johnson surmised that it must be a small patch. She had recently surveyed a trail where Solo had easily found a large patch of the invasive weed.

Conservation Dogs of Hawai’i has done only a few devil weed surveys so far, so it’s too early to know if the dogs are making an impact. But despite not finding anything here, the work wasn’t done. Johnson and Solo, heading back to the truck, planned to return later for another sweep of the trail.

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