Hummingbird Diseases – Pathogens to Preventative Measures

hummingbird disease
Hummingbirds do not commonly carry diseases but are susceptible to the diseases found in other birds. The Avian Poxvirus, Candidiasis, and Conjunctivitis have all been shown to affect the Trochilidae family of bird species. Properly sanitized bird feeders can help prevent the spread of disease.  

Like all wild birds, hummingbirds are susceptible to disease. Hummingbirds can pass diseases to other birds and, in rare cases, to humans. The best defense against hummingbird diseases is to keep hummingbird feeders clean and to follow state and local guidelines for feeding hummingbirds and other backyard birds.

The article below contains information on common hummingbird diseases and how to help prevent diseases from harming your backyard birds.

Can Hummers Get Diseases From Feeders?

Yes, they can; dirty feeding stations can harm and spread diseases amongst hummingbirds. In the interest of hummingbird health, it’s important to monitor your feeders and clean them often. Clean feeders ensure that hummers have a food source that nourishes them and keeps them healthy.

What Factors Create An Environment For Pathogens?

Pathogens can live just about anywhere outdoors. Factors like extended periods of heat, dirty feeding stations, multiple species of birds, and use of chemical pesticides, and humidity can create an environment for pathogen growth.

The best defense against germs is to keep feeders and feeding areas clean and sanitizedMake sure not to use pesticides in any areas in your yard. The chemicals are harmful to wild birds.

Hot Weather

The sugar water that hummingbirds eat ferments in hot weather. It can then become a harmful food source. Pathogens such as mold, bacteria, and fungus can grow and thrive in humid and hot environments, especially in fermenting nectar.

The odor of spoiled nectar can also attract unwanted guests, such as rats, insects, and raccoons, potentially increasing the likelihood of more disease to spread throughout the environment. It’s still ok to feed hummers in hot weather as it will keep them cool and provide energy, but make sure to clean the feeder and refill it with a fresh batch of nectar daily. 

Other Backyard Birds

Other wild birds can contaminate hummingbird feeders by bringing diseases as they perch and feed on the hummingbird’s food. The sugar water that hummingbirds love is popular with many other bird species. House Finches and Woodpeckers can drink from hummingbird feeders, and these birds can pass diseases onto hummingbirds.

Make sure to keep hummingbird feeders separate from other wild bird feeders. Also, position hummingbird feeders away from bird baths. Hummingbirds are tiny and can struggle to use bird baths anyway. This will also help further separate hummingbirdcs and other bird species.

diseased hummingbird

Diseases That Affect Hummingbirds

Hummingbirds are susceptible to diseases that affect other wildlife. A recent study of Anna’s Hummingbirds examined the health of the wild bird and hummingbird GI bacteria. Though further studies are needed, GI bacteria is an overall indicator of bird health.

Wildlife diseases that disrupt the balance of gut bacteria and absorption of nutrients can be especially dangerous. These are the most common hummingbird diseases, plus how they are transmitted and contracted.


  • Candidiasis is a fungal tongue infection. Hummingbirds get this disease through contaminated water sources or feeding areas
  • Adding honey to their food is a major source of this fungal infection. Hummers need white sugar, not honey, in their sugar water 
  • This fungus creates an imbalance of bacteria in the digestive tract, so hummingbirds have trouble digesting and absorbing nutrients from their food

Avian Conjunctivitis

  • Symptoms include swollen or crusty eyes, making it difficult for the birds to feed
  • Humans cannot catch this disease from wild birds, but the birds can pass the disease among each other
  • One strain of Conjunctivitis is transmitted from a bacteria called Mycoplasma gallisepticum, found in domestic chickens and turkeys

Avian Poxvirus

  • This Poxvirus promotes tumor growth most commonly on beaks, but also on legs, feet, and eyelids of birds
  • It can be transmitted between the avian species, but not to humans
  • Avian Poxvirus is contracted through a contaminated bird or feeding area, or contaminated perches
  • The tumors on their tongues make it difficult for the bird to eat if on the tongue, so they can’t properly absorb nutrients


  • Salmonella is contracted through contaminated water or food.
  • This disease can be spread between hummingbirds and humans.
  • Salmonella affects the digestive tract, meaning the hummers can’t absorb nutrients.
  • This can be a fatal disease for wild birds.
  • Symptoms include roughed feathers, diarrhea, and lethargy.

Other Wild Bird Diseases

In 2021, there were reports of a mysterious songbird illness. In Indiana, Kentucky, and the greater Audubon region, blue jays and European starlings were reported with crusty eyes and the inability to fly. Further, in the Atlantic region, more songbirds were reported to be sick and dying of this illness.

While hummingbirds were never seen to be affected, officials recommended all bird feeders be taken down and disinfected. The best prevention method for these pathogens is to keep hummingbird feeders clean and separated from other domestic and wild birds. Always follow state and local guidelines related to feeding backyard birds.

hummingbird feeding at a feeder

What You Should Do If You Find A Sick Hummingbird

Before going out to help any distressed hummingbird, make sure you put on disposable gloves. You’ll keep yourself, the bird, and the rest of your household safe by making sure not to touch the bird with bare hands.

You are allowed to try and pick up a hummingbird and try to feed it some hummingbird nectar. It’s possible that once it gets some food, the hummer will be able to fly off or perch again. If you see a dead bird, pick it up with disposable gloves, put it in a plastic bag, wash your hands thoroughly, and then call your local wildlife office.

In fact, the best way to help infected birds is to call your local wildlife office. These offices keep track of wildlife diseases in the area and need to be informed if you see a sick hummingbird or other wild bird. Always follow their advice.

A further note is that The Migratory Bird Treaty Act of 1918 prohibits taking in migratory birds as pets, trying to bait and trap them, and taking anything from the bird (like feathers), among other things.

With the knowledge of feeding hummingbirds proper food and keeping their food sources clean, what steps should you continue to take to create the safest environment?

Feed Hummingbirds The Best Type Of Feed You Can Make

  • Hummingbird nectar requires four parts water to 1 part white table sugar
  • Boil the water, add the sugar, and continue boiling for 2 minutes. Let cool to room temperature. Don’t add food coloring or red dye
  • Store excess food in the fridge for up to 2 weeks

Keep Hummingbird Feeders Clean

  • Using a bristle brush, clean with mild soap and hot water
  • Use a bleach mixture that is 1 part bleach to 9 parts water if the feeder is really dirty or there are known wildlife diseases in your area.
  • Allow feeder to air dry and refill with fresh food.
  • Separate hummingbird feeders from other wild bird feeders

These are two easy ways to help prevent wildlife diseases in your area.

Scientists are still learning about the numerous hummingbird species and which diseases affect them—helping all pollinators can create a more diverse and healthy environment. Bird enthusiasts and birders should follow the steps above to keep all avian and hummingbird diseases to a minimum.

Sarah Pearce

Sarah enjoys feeding hummingbirds in the warmer months, and a range of finches, woodpeckers, and cardinals in the cooler months. She enjoys researching and learning more about birds, gardening, and preserving food. She is learning how to maximize her small city backyard and is amazed at all the possibilities. She lives in southwestern Indiana with her family.

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