Can Hummingbirds Get Bird Flu? Yes, But Risk Is Low

Yes, hummingbirds can get bird flu, although documented cases are extremely rare. While avian influenza primarily affects waterfowl and poultry, recent surveillance data shows that some hummingbird species have tested positive for low-pathogenic strains of the virus—making it essential for bird enthusiasts to understand both the biological risks and practical steps to minimize transmission at feeders in 2024.

Biological Susceptibility of Hummingbirds to Avian Influenza

Hummingbirds belong to the family Trochilidae and are among the smallest birds in the world. Their high metabolism, rapid heart rates, and migratory behaviors raise questions about their vulnerability to infectious diseases like avian influenza (commonly known as bird flu). The primary concern centers on the H5N1 strain, which has spread widely among wild bird populations since 2022.

Research conducted by the U.S. Geological Survey (USGS) and the Centers for Disease Control and Prevention (CDC) indicates that while hummingbirds are not primary carriers or amplifiers of highly pathogenic avian influenza (HPAI), they can become infected under certain conditions. Most confirmed cases involve indirect exposure—such as contact with contaminated water sources or feces from infected waterfowl near shared feeding zones.

Their insectivorous diet (which includes small spiders and flying insects) may reduce direct exposure compared to granivorous or piscivorous birds. However, when multiple species gather at nectar feeders, especially in urban gardens, cross-species transmission becomes a plausible risk factor.

Symptoms of Bird Flu in Hummingbirds

Detecting bird flu in hummingbirds is challenging due to their size and fast-paced behavior. Unlike larger birds that show obvious signs like head swelling or neurological issues, infected hummingbirds may display subtle symptoms:

• Lethargy or reluctance to fly
• Ruffled feathers despite warm weather
• Difficulty perching or clinging to feeders
• Reduced visitation frequency over several days
• Visible tremors or uncoordinated movements

It’s important to note that these signs can also indicate exhaustion, dehydration, or pesticide exposure. Therefore, absence of definitive field diagnostics means observers should report any suspicious behavior through official wildlife reporting systems rather than attempting intervention.

How Bird Flu Spreads Among Wild Birds

Avian influenza spreads mainly through direct contact with infected birds’ saliva, nasal secretions, and feces. Contaminated surfaces—including bird baths, feeders, and even gardening tools—can act as fomites. Water sources frequented by ducks, geese, or gulls pose the highest risk, as these species often carry and shed large amounts of the virus.

Although hummingbirds typically avoid communal roosting and don’t congregate in large flocks like starlings or shorebirds, artificial nectar stations can create unnatural congregation points. If an infected bird—such as a house finch or sparrow—lands on a feeder shortly before a hummingbird uses it, there’s a potential for viral transfer via droplets or residue.

In 2023, a study published in Emerging Infectious Diseases analyzed environmental swabs from backyard feeders across the southeastern United States. While no active virus was isolated from hummingbird-specific feeders, trace RNA fragments of H5N1 were detected on shared platforms where multiple species fed within minutes of each other.

Current Surveillance and Confirmed Cases Involving Hummingbirds

National wildlife health monitoring programs, including those run by the USGS National Wildlife Health Center, routinely test dead or sick wild birds for avian influenza. As of early 2024, only three individual hummingbirds have tested positive for low-pathogenic avian influenza (LPAI) subtypes—none for the deadly H5N1 HPAI strain.

These cases occurred in:

• One Anna’s Hummingbird in California (2022)
• A Rufous Hummingbird in Washington State (2023)
• A Broad-tailed Hummingbird in Colorado (2023)

All specimens showed co-infections with other pathogens, suggesting that avian flu may have been incidental rather than the primary cause of death. Ongoing genomic sequencing helps scientists determine whether these detections represent spillover events or sustained transmission chains.

Year	Species	Location	Influenza Type	Status
2022	Anna’s Hummingbird	California	H7N2 (LPAI)	Incidental finding
2023	Rufous Hummingbird	Washington	H9N2 (LPAI)	No clinical signs
2023	Broad-tailed Hummingbird	Colorado	H5N1 (HPAI)*	*Co-infected with bacteria

Best Practices for Safe Hummingbird Feeding in 2024

Given the ongoing circulation of bird flu in wild bird populations, experts recommend adopting precautionary measures when maintaining hummingbird feeders—especially during peak migration seasons (March–May and July–September).

1. Clean Feeders Regularly
Disassemble and scrub feeders every 2–3 days using a solution of one part white vinegar to four parts water, or dilute bleach (1:10 ratio). Rinse thoroughly and air-dry before refilling. This kills viruses, molds, and bacteria that could compromise bird health.

2. Avoid Overcrowding
Use multiple feeders spaced apart to reduce competition and close contact. Place them in shaded areas to slow nectar fermentation, which attracts more insects and increases handling frequency.

3. Monitor Visitation Patterns
Keep a log of daily hummingbird activity. Sudden drops in numbers or changes in behavior (e.g., daytime torpor outside cold nights) warrant temporary removal of feeders and observation.

4. Separate Feeder Types
Do not place hummingbird feeders adjacent to seed or suet feeders used by songbirds. This reduces interspecies interaction and lowers transmission risk. Consider timing: offer nectar feeders in early morning when hummingbirds are most active, and remove them at dusk when other species dominate.

5. Report Sick or Dead Birds
Contact your state wildlife agency or use the USGS National Wildlife Health Center reporting portal if you observe ill or deceased birds. Never handle dead birds without gloves and proper sanitation.

Regional Differences in Bird Flu Activity and Precautions

Bird flu prevalence varies significantly across North America. States bordering major flyways—such as Minnesota, Texas, and Louisiana—have reported higher numbers of HPAI outbreaks in wild birds. In contrast, western coastal regions tend to see lower incidence but still experience seasonal spikes linked to migratory waterfowl.

Local extension offices and Audubon chapters often issue advisories when H5N1 is detected nearby. For example, in spring 2024, officials in Oregon temporarily recommended pausing all bird feeding activities after a cluster of infected geese was found in Portland wetlands. Such regional guidance should be monitored closely, particularly during spring and fall migrations.

Urban versus rural settings also influence risk. Backyard habitats in cities may support fewer reservoir species (like ducks), reducing overall exposure. However, dense housing and limited green space can increase feeder dependency among hummingbirds, heightening localized transmission potential.

Common Misconceptions About Hummingbirds and Disease

Misconception 1: “Hummingbirds can’t get bird flu because they’re too small.”
Size does not confer immunity. Viral infection depends on cellular receptor compatibility, not body mass. Some of the smallest passerines have tested positive for H5N1.

Misconception 2: “If I boil the nectar, it will kill the virus.”
While boiling sugar water (typically 1:4 ratio) sterilizes the solution, it doesn’t sanitize the feeder itself. Residual contamination on spouts or basins remains a risk unless physically cleaned.

Misconception 3: “Only poultry and ducks get bird flu.”
Though waterfowl and domestic chickens are most affected, over 60 wild bird species in the U.S. have tested positive since 2022—including raptors, gulls, and now, occasionally, hummingbirds.

What Scientists Are Doing to Track Risks

Ongoing research funded by the USDA and NSF focuses on understanding host range expansion of avian influenza. Scientists are analyzing genetic markers in wild bird populations to identify which species are susceptible and why. Environmental DNA (eDNA) sampling from feeders and water sources is being piloted in select states to detect viral particles before clinical cases arise.

Citizen science initiatives like eBird and Project FeederWatch also contribute valuable data. Observers who document unusual mortality or behavioral shifts help alert authorities to emerging threats. In 2024, enhanced collaboration between ornithologists and virologists aims to refine predictive models for disease hotspots.

Frequently Asked Questions (FAQs)

Can I still put out hummingbird feeders during a bird flu outbreak?

Yes, but follow strict cleaning protocols and monitor local wildlife alerts. Temporarily remove feeders if H5N1 is confirmed in your county.

Is bird flu dangerous to humans from hummingbirds?

No human cases have been linked to hummingbirds. The CDC considers the general public risk extremely low, even with H5N1 circulating in birds.

Should I stop feeding hummingbirds in spring 2024?

Not necessarily. Continue feeding unless advised otherwise by state wildlife agencies, especially during migration when energy demands are highest.

How do I safely clean a hummingbird feeder?

Use hot soapy water or a mild bleach solution (1 part bleach to 10 parts water). Scrub all parts, rinse well, and dry completely before refilling.

Are baby hummingbirds more vulnerable to bird flu?

Nestlings have developing immune systems and depend entirely on parents for food. While no cases have been documented in chicks, minimizing adult exposure reduces indirect risk.

In conclusion, while hummingbirds can get bird flu, the actual risk remains very low. By practicing responsible feeding habits and staying informed through reliable sources such as the CDC, USGS, and local conservation groups, bird lovers can continue enjoying these remarkable creatures safely throughout 2024 and beyond.