Meet Hunter and Stan, the red-tailed hawk and turkey vulture who are a Norristown zoo’s unlikely couple

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Zookeeper Jessica Ciaramello enters an enclosure at the Elmwood Park Zoo in Norristown, Pennsylvania, holding four dead white rats and a hunk of deer meat.

Inside, a red-tailed hawk named Hunter and a turkey vulture named Stan perch quietly on branches. The birds are extra hungry, because it’s the day after their weekly fast day.

Hunter is the first to make a move. She grabs one of the rats with her beak and hops toward Stan. After walking around and tearing off a few bites of the rat, she leaves the rest for the vulture to devour.

“After she took a nibble for herself, she knew, ‘Stan’s probably hungry too, so I’ll give her some,’” Ciaramello said, “which is so sweet.”

Zoo staff consider Hunter, roughly 22 years old, and Stan, roughly 20, a bonded pair. Despite their names, both birds are female. They’ve lived together in the same enclosure for at least a decade.

“Sometimes a bird will just choose one being to be with,” Ciaramello said. “Stan has definitely picked that one being to be with, and it’s Hunter, the red-tailed hawk.”

Sharing food, sharing nests

Ciaramello said it’s typical for the hawk and vulture to share food. Stan will sometimes nudge Hunter with her head as if to ask the hawk to bring her a rat, Ciaramello said. Sometimes, Hunter will hold a piece of meat in her talon while Stan tears at it.

“She’ll keep it still for her,” Ciaramello said. “Like, ‘I’ll hold it still so you can get some food,’ which is really cute.”

Zoo staff have also seen the two birds perching next to one another and grooming each other’s feathers with their beaks, a behavior typical of breeding partners known as allopreening.

“They get along,” Ciaramello said. “Existing together and helping each other out, getting food for each other, sitting next to each other, preening each other, just making each other’s lives better on the daily.”

Zoo staff say there are other signs that Hunter and Stan are more than just friends. When the two birds were younger, Ciaramello said they attempted to mate.

The two have also collaborated on nest building. Hunter, the hawk, did most of the work,  gathering sticks that fell on the ground of the enclosure and shaping them into a nest.

“Then Stan, if … you’re lucky enough to see it, will rearrange the nest in the way she wants it to be,” Ciaramello said. “It’s really interesting that that happens, because turkey vultures don’t really build nests.”

Hunter has laid eggs, and at times, Stan has sat on the eggs, Ciaramello said.

But here’s where the birds’ differences become a problem.

Zoo staff would have to quickly replace Hunter’s eggs with fake eggs. That’s because Stan, being female, couldn’t actually fertilize them, so they would rot. And turkey vultures love rotting things.

“Stan’s going to smell that egg, and she’s going to go over and start eating that egg,” Ciaramello said.

Hunter and Stan have similar backstories

Despite being different species, Hunter and Stan have a lot in common.

Both birds came to the Elmwood Park Zoo about two decades ago from wildlife rehabilitation clinics after being injured in the wild.

Both birds sustained fractures to bones in their right wings that did not heal properly, said veterinarian Michele Goodman, who directs animal care at the zoo. Each bird still has a pellet lodged in her wing.

Ciaramello said Hunter can still fly a little bit, but Stan, not so much. She thinks this might be part of why they get along so well.

“I feel like they just kind of depend on each other,” she said. “I think that Stan, on some level, realizes that Hunter can gain some of that air. She can swoop down and get the rat and bring it closer to her.”

Zoo staff aren’t sure when Hunter and Stan first met, but say they’ve been housed together and without other birds in the same enclosure since at least 2016.

“Sometimes when there’s a lack of mates, like there’s not another male turkey vulture or red-tailed hawk, they will find companionship in whatever is available,” Ciaramello said. “They had each other, so they luckily bonded together, and it would cause more stress to break them up than to leave them together.”

A few years ago, Hunter and Stan were separated for several weeks while Stan healed from an injury to her toe, Goodman said.

“Neither of the birds ate as well as they would have when they were together, which we would expect from Stan, because she was undergoing medical treatment,” Goodman said. “But we wouldn’t have expected any impact on Hunter.”

“I would assume she was scared because she was by herself,” Goodman added.

Are these birds in love?

To the human eye, Hunter and Stan’s relationship has all the hallmarks of a romantic partnership. But it may be impossible to know what the birds actually feel for one another.

“Obviously, we can’t ask [animals] directly what they feel,” said Zanna Clay, a psychologist at Durham University in England who studies the behavior of great apes and humans. “We can’t ask them about their inner experiences.”

Many scientists, including Clay, believe that animals experience emotion. A 2024 survey of 100 animal behavior researchers found that 78% think most or all birds have emotional responses that shape their behavior. But those researchers defined “emotion” differently. Some referenced emotion as a response to stimuli, others said it motivates behavior, while others referenced a connection to consciousness.

“Some people would argue … [that] some animals, particularly our close relatives like chimpanzees and bonobos, have many of the same emotions that we do — so pride, envy, disgust, rage, love,” Clay said. “Others would argue that it’s difficult to really know if that’s the case based on the objective evidence we have. So it really … depends on how you want to think about what emotions are.”

Human emotional concepts like love are shaped by culture and language, said Eliza Bliss-Moreau, a professor of psychology and scientist at the California National Primate Research Center at the University of California, Davis. She said humans have a tendency to try to intuit the mental states of others, both humans and animals.

“We can’t assume that we can just look at an animal and understand their emotional state,” Bliss-Moreau said.

Ciaramello, the zookeeper, hesitates to project human emotions onto Hunter and Stan. She sees their relationship as born of opportunity and what the birds may see as necessity.

“As a human being, … you want to say [it’s] friendship and love and all that fun stuff,” she said. “But as a [zoo]keeper, it’s, I think, a part of getting through the day-to-day and surviving.”

But scientists have found physiological signals that indicate bonds like Hunter and Stan’s may feel good, said Stephanie Poindexter, a biological anthropologist at the University at Buffalo who studies primate behavior. For example, studies have found decreases in the stress hormone cortisol after macaques collaborated with individuals they shared close bonds with and increases in oxytocin levels in chimpanzees after grooming with bond partners.

The evolutionary benefits of social connections include reproduction and having more eyes to watch out for predators or find food, Poindexter said. She theorized that living in the zoo, Hunter and Stan may think they can reproduce, or they may interact simply to stay stimulated.

“There is no doubt that there is some positive thing that they’re taking away from these interactions,” she said.

But saying the two birds are in love may be a stretch.

“It’s hard to define love anyway,” Poindexter said.