Pigeons, those hardy urban survivalists, rarely evoke much sympathy in humans.
But in the past week, many residents of the Russian capital, Moscow, have expressed alarm at the growing number of dead and dying pigeons on city streets.
What's most unnerving, say capital dwellers like Umid, is the way the normally spunky birds are behaving.
"When I walk to work, I usually see pigeons running and jumping around. But recently, they haven't been reacting to anything at all," he says. "When a person walks past them, they used to fly away. But now they just sit there in a kind of funk and don't even pay attention to you. They're just not normal. I've seen some pigeons behaving very strangely, turning around in circles."
Hundreds of Muscovites have noted the trend, many with online posts and graphic photographs of the so-called "zombie pigeons."
One Twitter user said a family meal was interrupted when an afflicted pigeon sitting on the ledge of an open window frame lost its balance and fell into the kitchen.
"I saw a pigeon sitting right in the street, its bill resting on the ground," another person wrote. "It's like a bird apocalypse."
Veterinarians and ornithologists have confirmed the phenomenon. Natalia Anisimova, a vet at Green Parrot, a Moscow clinic specializing in birds, says she's examined dozens of sick pigeons in recent weeks.
"There is an abundance of various infections, really, and each time something new comes up -- either some bacterial infection, or ornithosis, or salmonellosis, or Newcastle disease," she says. "Infections spread via bird-to-bird contact either through airborne droplets or dust."
"In the hands of Pablo Picasso, a pigeon became an embodiment of peace. But, in fact, in a sanitary sense, they're one of the dirtiest, stupidest birds there are.
On August 14, Russia's state veterinary service, Rosselkhoznadzor, confirmed that Newcastle disease and salmonellosis had been detected among the sick birds.
In crowded, summertime Moscow, there are fears the "zombie pigeons" may pose a health risk to their human neighbors.
At least some avian infections, including ornithosis and Newcastle disease -- a disease that can cause pigeons to stagger, turn in circles, and twist their heads upside down -- can be transmitted to people, although only rarely with serious consequences.
Russia's chief health inspector, however, says there is no cause for alarm. Gennady Onishchenko -- who last month banned Ukrainian chocolate as a potential health hazard -- on August 14 urged people to avoid touching sick or dead birds with their bare hands but said the authorities were taking no special measures to deal with the epidemic.
'Dirty, Stupid Birds'
He also appeared to reveal a personal distaste for rock doves, as common city pigeons are officially known. "In the hands of Pablo Picasso, a pigeon became an embodiment of peace," he said. "But, in fact, in a sanitary sense, they're one of the dirtiest, stupidest birds there are."
Viktor Kharlashin, the president of Pigeons of Russia, a Moscow-based enthusiasts organization, shares the sentiment.
Kharlashin, who keeps "5,000 perfectly healthy pigeons" in special coops at home, says rock doves have been a blight on the Russian pigeon empire ever since they were introduced to the country during a youth festival in 1957.
"Everything Onishchenko said is true. It's not only that they're dirty, but they also spread disease," Kharlashin says. "Ever since 1957, they've been inbreeding like crazy and their immune system is very weak. They can even be infected with diseases that never used to affect pigeons before. They all need to be destroyed."
To fans of the humble, hearty city pigeon, such pronouncements may seem harsh.
Umid, who grew up in Uzbekistan watching his father lovingly tend his own collection of doves and pigeons, says these normally tough urban birds deserve more respect than they get.
"I've always thought that birds are like an indicator of the state of the ecology around us," Umid says. "If something is happening to them, then there's reason to believe that the local ecology is going to have an impact on people as well. I often see how these birds are splashing around in puddles by the side of the road, close to the curb, in all kinds of oil and fluids. Poor birds."