In Los Angeles, coyotes walk the streets of densely-populated neighborhoods. You might wonder, what do these urban canines eat to survive? Biologists have been wondering the same thing. So they’ve recruited volunteers to help them gather coyote droppings.

Maybe you’ve seen these wily predators skulking the streets at dusk and dawn. In some parts of the country, including in L.A., the drought has brought them out of the mountains and canyons and onto our blocks in search of food and water.

Some think of coyotes as a menace to society. They lie in wait until we take our eyes off our cats and small dogs; then they strike.

Others are fans of these wily predators and advocate for their survival. Like Melanie Symonds, who keeps chickens in her backyard.

“Chickens are delicious to coyotes and I’ve lost more than I’d like to admit to those that have come through the yard,” Symonds says. “They’ve earned their trickster name, as far as I can say from my own experience."

Symonds closes up her chicken coop at night and keeps a close watch on the flock. Still, when the occasional hen is lost to a predator, she doesn’t hold it against them. In fact, Symonds believes we should be grateful.

“People don’t like to have certain vermin around, rats and mice, and [coyotes] actually do a tremendous job to keep the numbers of rodents in check,” she says.

Symonds has spent 18 years as  docent at Pasadena’s Eaton Canyon Nature Center. When the National Park Service started recruiting people like her for a study on the diet of coyotes, she jumped at the chance to start collecting coyote droppings -- also known as coyote scat.

About 30 volunteers gather at the Audubon Center in Debs Park. They're huddled around a table, looking at bowls of dried poop: bobcat and coyote.

Binta Wold helps run the Urban Coyote Project for the National Park Service. She says one way to tell the different kinds of scat apart is by the shape. Bobcat poop, for example, is shaped like a ball-and-socket joint.

“Often coyote scat has a characteristic twisted appearance. They’re a little bit smaller than dog scat usually,” Wold said.

The contents can also help determine the animal who left the scat behind.

“If you have a scat that you think is coyote, it’ll probably have bones or fur or seeds. They’re omnivores so they eat a lot of fruits and berries and things like that. And then occasionally also especially in urban environments there’ll be anthropogenic materials, so things like paper towels, food wrappers, barbecue chicken, we saw once, so a great diversity of different foods,” Wold says.

Justin Brown, a National Park Service ecologist, says he’s seen people actively feeding wildlife.

“I’ve seen several different occasions where they’re putting either food from their lunch out in an area and you can see the coyotes keep coming back,” Brown says. “You see possums, skunks, raccoons, coyotes, all eating from these piles. But then also people are putting plates of dog food out as well.”

Actively feeding wildlife is illegal, and animal control is trying to crack down on it. Wold is concerned this behavior could lead to coyotes that aren’t shy about approaching people in the hopes of finding food.

“If people do get bitten by coyotes, it's often because those coyotes had been fed before,” says Wold. “If you want to help wild animals, it’s a good idea to just respect them from a distance, and definitely don’t feed them or leave anything out in your yard that could be a food source for wild animals.”

The hope of the Park Service study is to inform residents and elected officials about coyote behavior -- dietary and otherwise -- when it comes time to make decisions about how to keep them out of urban areas. Some cities have approved measures to trap and kill coyotes roaming our streets.

Randi Feilich’s group, Project Coyote, lobbies for more humane measures.

“They’re probably the most persecuted predator. You know, if they’re not killed by inhumane trapping or illegal hunting or being hit by cars, they’re being poisoned regularly by anticoagulant rodenticides, you know, rat poison. And that’s also what’s killing off our owls, our bobcats, our hawks, our mountain lions,” Feilich says.

After the classroom part of the training, the volunteers split off to find coyote scat in parks, cemeteries and golf courses. One group heads to Rio de Los Angeles State Park. Volunteers walk along a dusty trail, stopping every few feet to examine what could be a coyote dropping. Brown wears latex gloves. He scoops the scat into a paper bag and labels it with a marker. But just as often, the samples they find are from dogs.

“You’ll see all these little things that are kind of jagged in shape. Sometimes you’ll see little tiny seeds, but they’re usually more uniform in shape. Where, what they’ve been eating all 100 percent of Pedigree or Alpo or something, there’ll be all these little pieces of cracked corn,” Brown said.

Brown says they’ll eventually test genetic samples. So finding scat with animal remnants is especially important.

“When you go to start actually looking at these scats, one little piece might make a big difference. Especially if there’s a bone, a tooth. Teeth are the most important part. So if you see something that has a tooth in it, make sure you grab that piece,” Brown said.

Brown says he was surprised by the level of public interest in the project. He received 180 applications, and picked 30 lucky volunteers for the scat-gathering phase.

One of them, Marydee Donnan, can hear coyotes howling near her home at night. She says some neighbors have lost cats -- but she’s hesitant to blame the coyotes.

“A very small percentage of coyotes’ diets is cat or pet. So, you know, the random cat that goes missing, everybody wants to blame the poor coyote and that’s not fair,” Donnan said. “The more we know about them, the more we might appreciate them as part of our urban environment and our wildlife.”

Over the next year and a half, the team of volunteers will continue to fan out to collect poop in 30 Los Angeles locations, from Griffith Park and Beverly Hills to Boyle Heights and Highland Park.

Once the scat is collected and dropped off, another team of volunteers will join scientists to dry, sterilize and sort the samples.

The Park Service expects to finish the coyote scat survey by the end of 2018.