He's sometimes called a royal swan, and oh, does he look it: big fella, bright white feathers, downy S-curve neck, with black flipper-feet and pumpkin-orange beak.
In the chill of this late-breaking winter, he glides elegantly along in the Swan Pond at Morris Arboretum. He's got no official name. If you call out, "Hey, pal," or "Over here, buddy," he ignores you just the same.
He's maybe 15, could go another decade or longer. And he used to have a mate, but no more.
Long story, but during a restoration project at the pond last winter, workers strung a plastic fence across the water to protect themselves from the swans, who tend to be very territorial. One morning, they found the female had gotten tangled up in the fence and died.
"It was really a terrible accident," says Paul W. Meyer, director of the Chestnut Hill arboretum. And it seemed to everyone that her mate - don't call him "husband" - was distressed to lose her.
Scientists wince when human qualities are assigned to wildlife, but we all have pets with feelings and personalities, so the temptation is to say the guy was all-out grieving for his gal.
He's not telling. Like a lot of men, he's not showing, either.
But we're not the only ones anthropomorphizing. Volunteers at the arboretum had nicknamed the pair Bonnie and Clyde after the notorious bank robbers/lovers who terrorized the West during the Depression. The swans - technically known as Cygnus olor, or mute swans - apparently got their bodacious nicknames because, like most couples, they scrapped from time to time.
And while our own romantic longings make us want to believe swans mate for life, Linda Boice, an environmental educator at the John James Audubon Center at Mill Grove in Montgomery County, blows that one out of the water.
"They are monogamous, but that doesn't necessarily mean partners for life," she says. In fact, about 10 years ago, scientists discovered that these so-called life-partner birds actually cheat on each other.
"They go on and have sex with other birds," Boice says. "I can't believe there's actually been money spent on studies like this."
Clyde is different, though in truth, not by choice. He's got a clipped wing, can't fly away, so unless he gets lucky with a drop-in, he'll forever be a life-partner bird without a partner.
The Bonnie-and-Clyde moniker seems strangely pop culture when you realize that John and Lydia Morris, the never-married brother-sister duo whose estate later became the arboretum, named their first swans Lohengrin and Elsa, for the Wagnerian opera's "knight of the swan" and his fair princess. This was shortly after the pond was built, in 1905.
The Morrises added a Love Temple on the shore, which sounds positively risque. No such luck. John and Lydia fed their swans from the temple steps, and today, newlyweds are photographed there as part of the arboretum's wedding package.
For wealthy Americans of a certain vintage, mute swans and ponds with love temples were just the thing for country estates. It was only later that mute swans, non-native in this part of the world, became undesirable in some places for their aggressive behavior and unstoppable appetites.
Occasionally derided here as "Genghis swans," the Brits gave them the "royal" designation in the 12th century. Royal or mute swans are native in England and were considered a status symbol from the get-go.
For hundreds of years, the beaks of cobs (males), pens (females) and cygnets (babies) were etched with a knife to identify their owners. Now, they're tagged by the queen's royal swan-keeper, who presides over the traditional swan-upping, or cygnet-counting ritual, every July along the Thames.
The Morrises' swans were celebrities in their own right. In 1910, American Suburbs magazine described them as "amiable creatures and very tame, answering to their names when called." Yo, Lohengrin!
At some point, the arboretum went swan-less - until 1982, Philadelphia's tercentenary, when the City of Ottawa, Canada's capital, presented Mayor William J. Green with a pair of birthday swans. Their names were Ariel and Titania, for the moons around the planet Uranus. (Ariel is also a spirit of the air in Alexander Pope's poem The Rape of the Lock, Titania the queen of the fairies in Shakespeare's A Midsummer Night's Dream. Either way, cool.)
Which brings us back to Bonnie and Clyde, who in their day were a popular draw. Wingspans up to 7 feet, 20 or more pounds of fluff, big nest on the ground when they were fertile, and eggs that raccoons and turtles often snatched.
Like his fellow mute swans, the unofficially named Clyde isn't really mute. He grunts and whistles and hisses, still a lot quieter than our native tundra and trumpeter swans.
He seems happy enough, though yesterday he was moved into a kiddie pool in the arboretum greenhouse. It's been so cold, his chow bucket froze, and the six bubblers that usually keep the pond from freezing weren't completely successful. On Monday, he'll likely rejoin his pond pals, a swarm of mallard ducks, whom he does not attack.
Meyer, the arboretum's 6-foot, 4-inch director, hasn't been so lucky. A few years back, he was clearing storm debris from the pond. He was bent over, back to the swans, when . . . pow!
"I got butted in the butt," Meyer recalls, a phenomenon known around these parts as "getting swanned."
Contact gardening writer Virginia Smith at 215-854-5720 or email@example.com.