Hummingbirds are amazing little creatures that bring joy to backyard bird watchers across North America. With their glittering, iridescent feathers and incredible flying skills, it’s no wonder why people love seeing these tiny birds visit their gardens. However, hummingbirds face many threats to their health and survival. One such threat is disease transmission at backyard hummingbird feeders.
What is the disease?
The disease found on the tongues of hummingbird feeders is called “hummingbird tongue disease.” It is caused by a parasite called Trichomonas gallinae. This single-celled protozoan parasite infects the mouths and upper digestive tracts of hummingbirds that come into contact with it.
Trichomoniasis, the disease caused by T. gallinae infection, is characterized by white or yellowish lesions and necrosis on the tongues, mouths, and upper esophagus of infected hummingbirds. The lesions obstruct the bird’s ability to feed normally. In severe cases, the tongue may be completely covered in necrotic material.
Infected hummingbirds often appear lethargic and emaciated. They may have ruffled feathers. The disease impairs their ability to feed, so they become weak and are at risk of starvation.
How do hummingbirds get infected?
T. gallinae is found in the saliva and crop fluid of infected birds. Hummingbirds contract the parasite when they come into contact with surfaces contaminated with this infectious material.
Backyard hummingbird feeders provide a prime transmission route. When an infected hummingbird feeds at a feeder, T. gallinae cells are deposited on the feeder ports and in the nectar. Subsequent visiting hummingbirds then pick up the parasite when they insert their tongues into the ports or drink the contaminated nectar.
In this way, T. gallinae can quickly spread through a local hummingbird population as more and more birds visit the contaminated feeder.
Other transmission routes include:
- Feeding on flowers visited by infected birds
- Drinking from puddles or water sources containing the parasite
- Coming into direct crop-to-crop contact during courtship or aggression
Migrating hummingbirds may also transport T. gallinae to new regions, facilitating its spread.
What does the disease look like?
There are several visual signs of Trichomoniasis infection to look out for in hummingbirds:
- Lesions on the tongue and mouth – Rough, yellowish or white lesions and ulcers
- Necrotic tissue – Dead, dried tissue coating the tongue
- Swollen tongue – The tongue appears enlarged and inflamed
- Difficulty feeding – Constant readjusting and moving tongue around the feeder port
- Lethargy – Weakness, less active behavior
- Ruffled feathers – Messy, ungroomed appearance
- Weight loss – Appearing thin and emaciated
Severely infected hummingbirds may also show signs of starvation as they become too weak to feed. They may be observed lying on the ground or perched with eyes closed.
Prevention and control
Here are some tips to help prevent transmission of Trichomoniasis at your hummingbird feeder and support hummingbird health:
- Clean feeders thoroughly every 2-3 days with a 10% bleach solution. Let air dry completely before refilling.
- Avoid overcrowding at feeders. Limit feeders and spread them out to minimize contact.
- Remove feeders temporarily if sick birds are observed. Disinfect all feeders before putting them back up.
- Rinse feeders daily with hot water to remove any buildup of mold or bacteria.
- Use a nectar solution of 1 part sugar to 4 parts water. Change nectar frequently.
- Provide insects, such as small mealworms or fruit flies, as a supplemental natural food source.
- Report sick hummingbirds to your local wildlife rehabilitation center for treatment.
Following these best practices for feeder hygiene, nectar replacement, and enrichment can help minimize disease spread and support happier, healthier hummingbirds in your yard.
Treatment
Unfortunately there is no highly effective treatment for Trichomoniasis in wild hummingbirds at this time. However, rehabilitation centers may try the following interventions:
- Antiprotozoal drugs – Medications like metronidazole help kill T. gallinae but can be difficult to administer to tiny hummingbirds.
- Supportive care – Providing fluids, nutritional support, and housing to allow the bird to recover strength.
- Antiseptic washes – Using dilute antiseptic solutions like chlorhexidine to wash the lesions and remove necrotic tissue.
- Hand-feeding – Manually feeding nectar with a syringe allows the bird to eat while lesions heal.
With intensive supportive care, some hummingbirds may fully recover. But treatment success rates tend to be low overall. Preventing transmission is the best way to protect backyard hummingbirds.
Conclusion
Hummingbird tongue disease, caused by the protozoan Trichomonas gallinae, is a severe threat to hummingbird health that readily spreads at backyard feeders. By following best practices for feeder hygiene, promptly removing sick birds, and supporting natural feeding, we can reduce disease transmission and help hummingbirds thrive.
While there is no cure, rehabilitation efforts and upgrades to feeding practices can still make a meaningful difference for these special birds. With some extra care and awareness, we can continue to safely enjoy hummingbirds and their magical presence in our gardens.
