Observe caution if sick birds visit feeders

Photo by Brent Connelly from Pixabay • Blue jays appear susceptible to the ailment that afflicted birds for the past months.

I received an email from Unicoi residents Judy and Bill Beckman about a distressing situation at their feeders.

“We sadly took down our feeders early this week,” the email read. “We began seeing house finches with swollen, crusty eyes and ruffled and missing feathers. 

The email also indicated that some of the Northern cardinals also had a lot of missing feathers and a ruffled look. The Beckmans noted that they are aware that cardinals molt, but added that it seemed like they were seeing more than usual. 

They’ve also seen some blue jays and a flock of robins with motley appearances and missing feathers.   

They had received an alert earlier this year from the Elizabethton Bird Club about a mysterious  disease that is causing bird die-offs. The alert described the victims having swollen eyes and ruffled feathers. 

“Any confirmation of that happening here now?  Any updates would be appreciated.

Photo by Bryan Stevens • A male house finch perched on a cable. These finches are native to the western United States but became established in the eastern states thanks to the illicit pet trade.

I answered the email, starting with the more immediate problem of the house finches. Back in the 1990s, house finches were decimated by mycoplasmal conjunctivitis. Humans can get infected with conjunctivitis, which is commonly called “pink eye.” 

According to the Project FeederWatch website, infected finches have red, swollen, runny or crusty eyes. In extreme cases the eyes become swollen shut and the bird becomes blind. Observers might find an infected bird sitting quietly while clumsily scratching an eye against its foot or a perch. While some infected birds recover, many die from starvation, exposure or predation. Since the early outbreaks, the disease has affected several other wild bird species, including American goldfinch, evening grosbeak and purple finch.

I recall seeing both house finches and pine siskins suffering from this disease. I haven’t seen it as often in recent years, which has been a relief.

Salmonella is another disease that can affect birds. As most people know, salmonella can also have serious consequences for human health. Finches, especially in the West Coast states of Oregon and California, have been hard hit by salmonella in recent months.

“Salmonellosis occurs periodically in pine siskins in some winters throughout their range. When large numbers of pine siskins congregate, the disease can spread rapidly causing high mortality. Most birds die within 24 hours of infection,” said California Department of Fish and Wildlife Senior Environmental Scientist Krysta Rogers, an avian disease specialist.

Birds become infected with salmonella when they ingest food, water or come into contact with objects, such as bird feeders, perches or soil, contaminated with feces from an infected bird. Sick birds often appear weak, have labored breathing, and may sit for prolonged periods with fluffed or ruffled feathers. Salmonellosis is almost exclusively reported from locations with bird feeders where birds congregate. Rogers advised that residents can help reduce disease transmission by removing bird feeders and bird baths. Allowing birds to feed on natural seeds rather than at bird feeders reduces contact between birds and helps slow spread of the disease. Some of the flocks of finches have been exceptionally large this winter, which is why it’s a good idea to closely monitor the birds at your feeders. At the first sign of illness, take steps to disinfect feeders. It’s a good idea to clean feeders on a regular basis. A spray with a weak bleach water solution followed by a few swipes with a clean towel can help. Once an outbreak is evident, however, the best course would be to stop feeding birds for a short period.

Photo by Bryan Stevens • A flock of pine siskins carpets the ground beneath some feeders as they forage for food.

Songbirds aren’t the only birds affected by disease outbreaks. Waterfowl are often vulnerable. Like finches, many species of ducks and geese also form large flocks. Some of the diseases that can run rampant in waterfowl populations include avian influenza, avian cholera and avian botulism. According to the Ducks Unlimited website, major avian botulism outbreaks have been reported throughout North America for more than a century. In 1910, avian botulism resulted in the deaths of millions of waterfowl in California and Utah, and another incident in 1952 killed an estimated 4 million to 5 million waterfowl across the western United States.

In 1999, the West Nile virus, a mosquito-borne disease, arrived in the United States. This disease is typically a mild nuisance for most infected people, but in some circumstances the virus can be lethal. The virus, which first appeared in the United States in 1999 after being discovered in 1937 in the African nation of Uguanda, also didn’t confine itself to the human population. Soon after its arrival in the United States, the virus began decimating American crows. Two decades later, experts have been able to study the consequences of West Nile virus on both humans and wild birds.

According to an article by Hugh Powell published Oct. 15, 2010, on the All About Birds website, the disease afflicted crows more than any other bird species. “West Nile virus hit American crows particularly hard,” Powell wrote. “When the disease first appeared in New York City, in summer 1999, nearly 5,500 crows died in four months. Tests suggested the disease was 100-percent fatal to crows.” Many other species, from jays and magpies to gulls and chickadees, also proved susceptible, according to the All About Birds article.

Millions of birds died as West Nile swept across the continent in just five years. An interesting thing happened as the virus spread across the country. As viral diseases often tend to do, West Nile apparently became less virulent. The American crow population did hit frightening lows, but the species appears to have managed to rebound.

Where’s the silver lining in regard to all these stories? Here is a sliver of light through the dark clouds. Birds are resilient, just like humans. They can usually overcome anything nature might throw at them.

I suspect there could be several different diseases at work that are causing multiple but unrelated die-offs among certain birds. The house finch bacterial disease is a recurring problem for this species.

I do think that the cardinals, blue jays and perhaps the robins are simply having difficult molts. Molting, or the process of shedding and replacing feathers, doesn’t always go smoothly for crested birds like jays and cardinals. The bald-headed cardinal is a late-summer fixture.

Here’s a significant announcement made on Sept. 13. In a joint statement issued by the Cornell Lab of Ornithology and the Cornell University College of Veterinary Medicine.

“All states affected by the mysterious bird illness of summer 2021 have lifted their do-not-feed recommendations. No cause has yet been determined, but cases are no longer being reported.”

I think the Beckmans made the right decision to remove their feeders. In a couple of  weeks, I think they can put the feeders back out, monitor carefully, and see if any signs of disease return. 

Contagious diseases, particularly among flocking birds, are a fact of life, just like the cold and flu season for humans. We can, however, take steps to mitigate outbreaks.

Keep feeding the birds, but play the diligent host. Put out only the amount of seed that visiting birds can eat in a single day. Monitor the flocks for any sign of illness and respond quickly if such signs are detected. Yes, do keep feeding the birds, but be safe and attentive while doing so.

Photo by dbadry/Pixabay.com • Blue Jays often create food caches for acorns and other items. This jay is leaving a feeder with several peanuts thanks to an expandable esophagus.

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