Hummingbirds are amazing little creatures that brighten up our gardens and yards with their beauty and activity. Watching them flutter around our flower beds and feeders brings us so much joy. However, there are times when we find a lifeless hummer at or near a feeder and wonder what happened. This is heartbreaking, so understanding what kills hummingbirds at feeders is important for their health and survival. There are several potential culprits that could lead to their demise. Let’s explore those in more detail.
Diseases
Hummingbirds can contract diseases just like any other animal. There are a few main illnesses that impact hummingbirds frequently at feeders:
Aspergillosis
This is a fungal infection often caused by contaminated feeders. The Aspergillus fungus thrives in warm, moist environments. Poorly cleaned feeders can allow the fungus to grow. As hummers drink nectar from affected feeders, they ingest the spores which then cause respiratory issues. Aspergillosis can kill hummingbirds by making it difficult for them to breathe. Keeping feeders clean is crucial to avoid this disease.
Avian pox
Avian pox is a viral infection. The lesions caused by the virus impair a hummer’s ability to feed and fly. Contaminated perches like feeders spread this disease quickly. While avian pox is rarely fatal on its own, the open sores leave birds vulnerable to secondary infections. Isolating sick birds when possible helps control outbreaks. Proper sanitation of feeders and bird baths limits transmission opportunities.
Salmonella
Salmonella bacteria can infect hummingbirds, often through contaminated nectar or surfaces like feeders. Infected hummers may appear weak, lethargic, and fluffed up. They may also have pasty, green diarrhea. Dehydration from diarrhea can contribute to mortality. Basic precautions like washing hands before handling feeders and not letting nectar sit out too long reduce salmonella risks.
Predators
While feeding, hummingbirds are vulnerable to predators. Feeders attract birds but can also draw unwanted guests. Possible predators include:
Cats
Free-roaming pet cats can easily prey on hummingbirds visiting yard feeders. Cats that are excellent bird hunters may specifically target feeders. The most vulnerable hummingbirds are fledglings and sick adults. Keeping cats indoors reduces risks. Supervising cats outdoors prevents stalking opportunities.
Larger birds
Crows, jays, shrikes, and similar large birds may pick off hummingbirds at feeders. More aggressive species may actively harass hummers to maintain feeder control. Avoiding overcrowded feeders and using feeders with perch barriers helps limit bullying. Hanging feeders in sheltered spots provides cover.
Insects
Praying mantises are infamous hummingbird hunters. Their camouflage and patience make them experts at snatching unsuspecting hummers. Wasps, hornets, and ants may also kill smaller hummers, particularly if the bird is already debilitated. Defensive measures like reducing insect habitats near feeders and using pesticides can help curtail the threat.
Snakes
Certain snakes like the sharp-shinned hawk will prey on hummingbirds at feeders. These ambush predators rely on stealth and camouflage to attack. Trimming vegetation around feeders reduces hiding spots. Snakes tend to avoid vibrations, so strategic placement of feeders deters them. Motion-activated sprinklers also discourage snakes. Knowing local species helps assess risks.
Extreme weather
Hummingbirds are sensitive to weather extremes due to their tiny size. Prolonged cold temperatures or intense heat can be fatal. Other inclement weather can also kill hummingbirds at feeders:
Cold snaps
Frigid nights can put hummingbirds into torpor. If they remain trapped in torpor too long, their fat stores deplete and they starve to death. Providing emergency nighttime heat allows hummingbirds to break torpor and access feeders. Indoor shelters are ideal during cold fronts.
Heat waves
Extreme heat dehydrates hummingbirds quickly. Spray mists, bird baths, and drip systems supplement their fluid intake on scorching days. Well-shaded feeders also offer respite from the sun. Switching to chilled nectar formulas keeps feeders cooler.
Storms
Strong winds, hail, and rain from thunderstorms can kill hummingbirds if they get trapped outdoors. Nearby shelters allow hummers to take cover. Wrapping feeders helps prevent damage. Monitoring forecasts helps prepare for storms. Bringing feeders inside is safest when serious weather is imminent.
Contaminated nectar
Dirty or spoiled nectar in feeders can be lethal to hummingbirds in several ways:
Mold
Nectar naturally develops mold if left out too long in warm conditions. Ingesting moldy nectar can make hummingbirds sick. The metabolic stress may lead to death. Strict nectar hygiene, like changing it every 2-3 days, prevents mold growth. Refrigeration slows spoilage if changing nectar daily isn’t possible.
Bacteria
Bacteria thrive in old nectar, especially in warm weather. Salmonella and pseudomonas bacteria produce toxins. Consuming contaminated nectar can cause fatal digestive issues in hummingbirds. Always sterilizing feeders and using fresh nectar reduces bacteria.
Fermentation
Yeast naturally occurs on hummingbird feeders and flowers. In nectar, it starts fermenting sugars into alcohol and produces carbon dioxide. The resulting fizzy/alcoholic nectar can intoxicate hummingbirds. The simplest solution is nectar replacement every 2-3 days before fermentation happens.
Chemicals
Nectar made with unsafe water or stored in dirty containers may contain hazardous chemicals. Things like chlorine, fluoride, and cleaning product residue can poison hummingbirds. Use filtered or bottled water for mixing nectar. Avoid old or damaged plastic containers.
Sugar substitutes
Artificial sweeteners may seem convenient but can be highly toxic if fed to hummingbirds. Even small amounts of sugar substitutes like xylitol, sorbitol, erythritol, and artificial sugars are dangerous. Only use plain white table sugar or commercially-made hummingbird food.
Feeder position and design
Where and how a feeder is installed can create unintended hazards:
Flying into windows
Hanging feeders directly against windows leads to fatal collisions as hummingbirds rapidly fly to and from the nectar source. Move feeders well away from windows or apply decals and deterrents to reduce impacts.
Improper cleaning tools
Using soaps, detergents, or scrub brushes to clean feeders leaves toxic chemical residue behind. The chlorine in bleach is also extremely dangerous. Only use hot water, white vinegar, or a mild 10% bleach solution as cleaners. Use bottle brushes, not wire scrubbers.
Leaking nectar
Exposed nectar dripping down the base or leaking from the reservoir attracts stinging insects. Bees, wasps, and ants may swarm and kill hummingbirds. Avoid leaky feeders or place a catch tray beneath them. Routinely clean build-up.
Falling feeders
Insecurely mounted feeders that detach and fall, especially in windy conditions, can injure or kill hummingbirds beneath them. Use sturdy hooks, chains, and poles specifically made for hanging bird feeders. Check attachments frequently for wear.
Misuse of insecticides
Many common insecticides are highly toxic to hummingbirds. Direct contact or ingestion from contaminated feeders can be lethal:
Nectar additives
Products marketed to add to nectar as insect repellents often contain synthetic pyrethroids like permethrin. These chemicals are extremely hazardous if ingested by hummers. Never use insecticidal nectar additives.
Treating flowers/feeders
Applying liquid or granular insecticides directly onto flowers or feeders exposes hummingbirds to concentrated toxins. This includes topical repellents as well as systemics taken up by plants. Always read labels carefully and follow directions.
Bug zappers
Electronic “bug killers” use ultraviolet light to attract and electrocute insects. However, they can’t distinguish between bugs and hummingbirds. If positioned near feeders, hummers may fly into them and be killed. Keep well separated.
Pesticide drift
Using any insecticide, herbicide, or fungicide near hummingbird feeders puts birds at risk of poisoning through contact. Spray drift is impossible to completely prevent. Limit use or cover/remove feeders until products thoroughly dry.
What NOT to do
Certain common recommendations can actually harm or kill hummingbirds. Avoid these risky actions:
Red food dye
Adding red dye to clear nectar may seem decorative, but it provides no benefit and could be toxic. Stick to basic sugar water, no dyes needed to attract hummers. Food coloring is unnecessary.
Honey
Pure honey ferments rapidly into alcohol, even faster than simple sugar water. Honey can also transmit fungal spores. Never add honey to hummingbird nectar. The only safe sweetener is white sugar.
Overcrowding
Clustering too many feeders close together increases competition and disease transmission between hummers. Space multiple feeders widely to allow territorial needs. Avoid cramped feeder “traps.”
Mixing own nectar
Well-meaning DIYers may use improper sugar ratios or unsafe ingredients in homemade nectar. Unless you have exact recipe knowledge, use pre-made commercial mixes to ensure safety.
Placement near bee/wasp nests
Situating hummingbird feeders too near hives or nests stirs up angry insect attacks. Bees and wasps then swarm the feeder and kill hummers. Scout for colonies first and place feeders a safe distance away.
Conclusion
Hummingbirds are delicate creatures that we aim to provide food and shelter for with our feeders. However, these feeders can also contribute to their injury or death if used improperly or positioned unsafely. Basic measures like maintaining hygienic conditions, discouraging predators, and protecting from weather swings go a long way in preventing tragedy. Avoid toxic chemicals and stick to plain sucrose-based nectar. Be proactive, and research hummingbird care guidelines before installing feeders. With smart, conscientious feeder management, we can enjoy their beauty without sacrificing safety. The life of a single hummer matters, so staying informed on risks helps ensure our feeders bring joy, not harm.
