Hummingbirds are a familiar sight in many backyards, especially when flowers are in bloom. But you may have noticed these tiny birds are also more active right before, during, or after a rainfall. So why do hummingbirds seem to come out when it rains? There are a few key reasons.
They capitalize on increased nectar production
Flowers produce more nectar when it rains to attract pollinators after a dry spell. The rain essentially “waters” the plants and enables them to ramp up nectar production. Hummingbirds know this and will readily visit flowers to feast on the newly available nectar buffet. This is likely a key reason you see more hummingbird activity during and following rainfall.
Drinking and bathing
In addition to increased nectar availability, rainfall provides hummingbirds with direct access to fresh water for drinking and bathing. Hummingbirds have very high metabolisms and must consume up to half their body weight in nectar each day to avoid starvation. This requires frequent periods of drinking to replenish lost fluids.
Raindrops collect on leaves and petals, allowing hummingbirds easy access to rainwater to quench their thirst. Hummingbirds will also bathe in rainwater to keep their feathers in optimal condition. So a rainstorm provides a convenient drink and bath opportunity.
Insects emerge after rain
While hummingbirds get most of their nutrition from nectar and plant sap, they also consume small insects for essential proteins. A rainstorm triggers higher insect activity and emergence once the rain passes. So hummingbirds can capitalize on this increase in available insect prey.
Some examples of insects that become more abundant after rainfall and that hummingbirds readily feed on include:
- Mosquitoes
- Gnats
- Aphids
- Spider mites
- Thrips
- Ants
Feeding on these insects provides hummingbirds with an important source of protein and other nutrients to supplement their primarily sugar-based diet from nectar.
Chasing flying insects
Not only does rainfall increase insect abundance, it also stimulates flying insect activity. Hummingbirds will opportunistically feed on any small flying insects disturbed by the rain. Some examples include:
- Termites
- Fruit flies
- Fungus gnats
- Midges
You may see hummingbirds darting around in the rain snapping up any insects they find taking to the air. This provides a convenient meal on the wing.
Washing spider webs away
Hummingbirds often get caught in spider webs, which can hinder their ability to fly and forage efficiently. Rainfall washes away spider webs, creating a safer foraging environment free of these sticky traps. So post-rainfall is an optimal time for hummingbirds to access nectar sources before new spider webs start accumulating again.
Fewer predators are active
Bird-hunting predators—like hawks, falcons, and shrikes—are less active during rainy conditions. This gives small birds like hummingbirds a greater opportunity to forage while risk of predation is temporarily reduced. However, hummingbirds must still remain vigilant, as ambush predators like praying mantises will capitalize on any hummingbirds slowed by wet feathers.
Unique Adaptations for Rainy Conditions
Hummingbirds have several unique anatomical and physiological adaptations that allow them to thrive in rainy conditions when other species may opt to hunker down and wait it out.
Sloped shoulders
The characteristic sloped or hunched shoulder appearance of hummingbirds allows rainwater to run off their backs without pooling and weighing down feathers. This rain-optimized shoulder design allows hummingbirds to continue flying and foraging even in wet conditions.
Shakes water off feathers
Hummingbirds have been observed using body shakes to expel water quickly from their plumage. Shaking motions transfer water droplets from feathers out into the surrounding air through centrifugal force. Other bird species will fluff feathers to achieve similar drying effects.
Preens oil into feathers
Hummingbirds have a special gland near the base of their tail that secretes preen oil. They distribute this oil through their feathers using their long slender bill. Preen oil coats and waterproofs their feathers to prevent soaking and maintains insulative capacity if feathers do get wet. This allows hummingbirds to retain body heat in wet, cold conditions where other species may lose dangerous levels of heat.
Small body size
The tiny body size of hummingbirds makes them less impacted by heavy rain compared to larger birds. Their lightweight bodies and proportionally strong flight muscles also allow hummingbirds to maintain efficient hovering and rapid forward flight even with the aerodynamic drag introduced by wet plumage. Larger birds struggle more with wet feathers.
High metabolism
Hummingbirds have extremely high metabolic rates to support their unique hovering ability and small body size. This metabolism generates considerable internal body heat. The heat helps keep a hummingbird’s core temperature elevated even when its plumage gets wet and outside air temperatures drop during rain.
Lowers body temperature
If conditions are cold enough, hummingbirds can lower their high metabolic rate to induce a mild state of torpor. This torpor hypometabolic state reduces their internal body temperature and conserves precious energy reserves. So hummingbirds can essentially hibernate through periods of heavy rainfall and low insect availability until clear skies return.
Do all hummingbird species behave this way?
The various hummingbird species found across North, Central, and South America exhibit some differences in their comfort with rainy conditions. But most do actively forage at the onset of rainfall for the reasons outlined above.
Rainforest species adapted to rain
Hummingbirds native to tropical rainforests are well-adapted to frequent rainfall given their environment. This includes gems like the vibrant violet sabrewing and green-bellied brilliant. They will be less deterred by rain compared to arid-zone hummingbird species.
Rufous hummingbird avoids rain
The rufous hummingbird breeds farther north than any other hummingbird species. It shows greater aversion to rainfall given it is not as accustomed to wet conditions. Rufous hummingbirds will show less foraging activity when rainfall exceeds a light drizzle.
Rain-adapted ornamental species
Many tropical ornamental hummingbird species kept in aviculture are rainforest natives and comfortable getting wet. For example, the reddish hermit and white-necked jacobin will readily forage in tropical downpours.
Rain as a flexible opportunity
While certain habitats and species show adaptations for wetter conditions, hummingbirds are in general flexible and opportunistic feeders. They will seize the opportunity of increased food availability and reduced competition that rainfall temporally introduces into an environment, even if it means getting pelted with raindrops for a bit.
Do hummingbirds get cold in the rain?
Hummingbirds are susceptible to losing body heat when exposed to wet, cold conditions for extended periods. However, adaptations like torpor, high metabolism, and heat-retaining plumage modifications allow hummingbirds to maintain adequate body temperature and energy reserves during short rainfall events.
Healthy wild hummingbirds are well-equipped to handle rain, but here are some signs a specific individual may be in trouble and in need of rehabilitative assistance:
- Feathers soaked and matted against the body
- Shivering
- Lethargy and reduced responsiveness
- Lack of attempt to preen
- Loss of ability to fly
If a hummingbird is displaying these symptoms following prolonged exposure to heavy rain, it made need external warmth and prohibition before being able to recover and return to the wild. But most hummingbirds can maintain sufficient warmth and energy levels during typical rainy conditions.
Unique behavioral adaptations for rain
Beyond their physical adaptations, hummingbirds display some clever behavioral adaptations when rains arrive that further promote survival:
Start fever
Hummingbirds can briefly increase their high core body temperature before rainfall hits. This fever primes their metabolism to withstand chillier wet conditions about to occur.
Bath in rain drops
Hummingbirds will expose their wings and tail feathers to falling raindrops for a refreshing bath. This keeps their plumage clean and functional.
Perch with head elevated
A hummingbird will rotate its perched body so its head points up during rainfall. This allows it to watch for flying insects while keeping its back and tail feathers safely pointed down to shed water.
Seek shelter
Hummingbirds will periodically duck under the cover of leaves or other vegetation to avoid the heaviest downpours. This gives their feathers a break from the relentless rain. They can then pop back out during lulls to continue feeding.
Puff up feathers
Fluffing their plumage traps more insulating air between feathers and expands their overall body size. This enhances water resistance and heat retention.
Reduce activity
Hummingbirds rely on food sources like nectar that can quickly dilute in heavy rain. During intense storms, hummingbirds will conserve their energy by perching for long periods until the weather improves enough to warrant expending energy to forage again.
Unique challenges hummingbirds face in rain
While equipped for wet conditions, hummingbirds do face increased threats and energy demands during storms that must be compensated for.
Cold stress
Wet feathers lose insulative capacity. Small hummingbird bodies then have to work harder to maintain sufficient heat and prevent hypothermia. This drains their limited energy reserves.
Flower dilution
Heavy rain washes away nectar, forcing hummingbirds to visit more flowers to meet their extreme energy requirements. This demands more time and calories for foraging.
Reduced feeding
Low visibility, strong winds, cold exposure, and increased energy expenditure make feeding progressively more difficult in heavy or prolonged rainfall. Hummingbirds may not be able to consume enough to keep pace with their metabolism.
Bacterial growth
The moist conditions created by rain promote bacterial growth in flowers. Consuming higher bacteria loads along with nectar could potentially expose hummingbirds to more pathogens.
Displacement
Hummingbirds can get displaced from their foraging territories and food sources by rain and winds. Without adequate refueling, displaced individuals may not survive until they can reorient back to their habitat.
Nest flooding
Hummingbird nests in the cavities of trees or nestled under dense vegetation can flood in heavy rainfall. Chicks and eggs are put at risk if parents cannot keep nests sufficiently dry and warm.
Do hummingbirds prefer rainy weather?
Hummingbirds do not “prefer” rainy conditions. The risks and energy costs outweigh the foraging benefits for most species. However, hummingbirds are brilliantly adapted to make the most of rainfall through their behavior and physiology when it does occur in their environment. They adeptly exploit the specific opportunities rain temporally introduces.
Here is a quick summary of the advantages and disadvantages of rain from a hummingbird’s perspective:
Potential Advantages
- More abundant nectar and insects
- Drinking and bathing water source
- Cooler conditions
- Washed away spider webs
- Fewer bird-hunting predators active
Potential Disadvantages
- Energy-draining cold exposure
- Dilution of nectar
- Impaired foraging and visibility
- Increased pathogen exposure
- Challenges of displacement
So rainy weather presents a delicate balance of costs and benefits. Overall, hummingbirds do not want it to rain, but they will take advantage of these otherwise challenging conditions if they must occur. Their incredible adaptability enables them to do so.
Do hummingbirds fly and forage normally in rain?
Hummingbirds are light enough and strong enough fliers to maintain their characteristic hovering and rapid forward flight during light-to-moderate rainfall. However, during heavier downpours their normal flight behavior may be impacted in the following ways:
- Shorter foraging bouts
- More frequent rests and small bursts of activity
- Seeking covered shelter periodically
- Reduced aggressiveness at feeders as birds concentrate on feeding
- Preferring lower exposed perches over higher exposed ones
- Spending more time feeding versus territorial defense
Hummingbirds seem to understand that conserving their energy is key during unfavorable wet periods. So they will adapt their normal active behavior to expend only what is essential to avoid starvation until fair weather returns.
Conclusion
In summary, hummingbirds are remarkably skilled at exploiting rainy conditions to their advantage despite the inherent challenges wet weather introduces. Their evolutionary adaptations help them survive and even flourish during rainfall through behavioral and physiological mechanisms that provide energy, protection, and food sources.
While not necessarily their preferred foraging conditions, hummingbirds can continue meeting their extreme metabolic demands as long as periods of heavy precipitation are broken up by drying intervals. This allows their specialized rain adaptations to recharge and realign for any forthcoming storms. So next time it rains, take a closer look at the hummingbirds energetically buzzing around your backyard before the sun breaks through again!
| Physical Adaptations | Behavioral Adaptations |
|---|---|
| Sloped shoulders for water runoff | Starting a fever to prime metabolism |
| Shaking water off feathers | Bathing in falling raindrops |
| Waterproofing with preen oil | Perching with head up |
| Small body size | Seeking shelter |
| High metabolism and heat generation | Puffing up feathers |
| Torpor to conserve energy | Reducing activity |
