Hummingbirds are amazing little creatures. They are the smallest birds in the world, yet they have incredibly high metabolisms that require them to feed frequently throughout the day. Hummingbirds have specially adapted beaks that allow them to drink nectar from flowers. There are a few reasons why you might observe a hummingbird with its beak open:
Regulating Body Temperature
Hummingbirds have a very high body temperature compared to other birds, generally around 105°F. This high temperature allows them to have the energy they need to rapidly beat their wings up to 80 times per second! However, it also means they are at risk of overheating. To help regulate their body temperature, hummingbirds will open their beaks to release excess heat. This behavior is called gaping.
You are most likely to see gaping behavior on hot days. When a hummingbird inserts its beak into a flower, the rapid lapping of nectar generates even more internal heat. Opening the beak allows air to flow over their tongue and dissipate heat. This helps them avoid reaching dangerous hyperthermic levels that could lead to death.
Panting
In addition to gaping, hummingbirds will also pant to release heat. Their small size and high metabolism make panting an efficient way to evaporated moisture from their respiratory system. This evaporation has a cooling effect. Panting may be accompanied by rapid movements of the throat and chest.
Panting is similar to gaping but the beak will open and close repeatedly. You may see the throat feathers moving as air is pushed in and out. Panting is an extreme heat response, indicating the hummingbird is struggling to dissipate enough heat just through gaping.
Calling
Hummingbirds make squeaking, chirping and twittering sounds. Opening their beak allows them to vocalize. Hummingbirds may call to attract a mate or to communicate with other hummingbirds warning them away from a food source or nesting area. You can recognize calling by listening for high-pitched vocal sounds coming from an open beak.
Preening
Like all birds, hummingbirds use their beaks to preen and groom their feathers. This is essential to keep their plumage in good condition so they can fly efficiently. You may see a hummingbird open its beak to bite and scratch itches, distribute oil from the preen gland, and realign barbules on feathers.
Preening requires full extension of the neck which opens the beak. A hummingbird will perch conveniently and systematically preen different areas. Watch for organized grooming and scratching motions if you suspect preening is occurring.
Thermoregulation During Torpor
Torpor is a state of decreased physiological activity and temperature that hummingbirds enter to conserve energy. Their high metabolism requires a lot of calories, so torpor allows them to survive periods when sufficient food is not available.
During torpor, a hummingbird’s body temperature drops from around 105°F to as low as 50°F. This substantial temperature reduction slows their metabolism, breathing, heart rate and overall energy use. A torpid hummingbird will appear immobile, with feathers puffed out for insulation.
To prevent their temperature from dropping to fatal levels, torpid hummingbirds can open their beak slightly to allow heat dissipation if needed. This fine-scale thermoregulation lets them remain in torpor without risk of death.
Diagnosing Health Issues
Sometimes an open beak indicates a health problem in hummingbirds. Issues like infections, nutritional deficiencies, trauma or metabolic disorders can all cause abnormalities in breathing and beak control. Examples include:
- Labored breathing with the beak open can be a sign of respiratory infection or obstruction.
- Keeping the beak open for prolonged periods may indicate a deficiency of calcium or vitamin D needed for muscle control.
- Injuries and neurological issues due to toxins or trauma can also impair a hummingbird’s ability to fully close its beak.
- Diseases like avian malaria can cause weakness and loss of muscle coordination leading to gaping.
If you notice a hummingbird keeping its beak open consistently over several hours, and it is not actively breathing heavily or calling, something may be wrong. Seek wildlife rehabilitation if you suspect the hummingbird is sick, injured or orphaned.
Curiosity
Hummingbirds are naturally very curious creatures. They explore the world around them using sight and smell. You may catch a hummingbird with its beak open simply because it is checking something out!
Hummingbirds will investigate anything new or different in their environments. They tend to be attracted to the color red, as it signifies flower nectar. A male hummingbird may open his beak to sniff a red object or new bird feeder to determine if it may provide food.
Hummingbirds also remember flower locations from previous visits. One with an open beak may be sniffing the air to orient itself towards a known nectar source. The excellent sense of smell in hummingbirds is useful for finding flowers and approaching feeders.
Feeding
The most straightforward reason a hummingbird’s beak would be open is that it is actively feeding. Hummingbirds have specially adapted tongues and beaks perfectly designed for accessing nectar. Here are some details on how hummingbirds use open beaks when feeding:
- Their long, forked tongue shoots in and out of the open beak to lap up nectar.
- They can lick nectar up to 13 times per second!
- The tubes formed by their tongue trap nectar via capillary action.
- Their beak shape matches different flower types to optimize nectar extraction.
- The tip of their tongue has hair-like structures that soak up nectar.
- As nectar enters the open beak, it moves back towards the throat by the action of the tongue.
Watch for extension of the tongue and rapid lapping motions in and out of the beak when a hummingbird is feeding. This is the most energy intensive activity of their day, requiring an open beak and fast tongue action.
Conclusions
Hummingbirds have specially adapted physiologies related to their incredible hovering flight and nectar-feeding. As a result, they have unique behavioral mechanisms like gaping and panting to maintain homeostasis. Observing an open hummingbird beak can signify thermoregulation, calling, preening, curiosity, illness or feeding.
Understanding the reasons behind this behavior provides a glimpse into hummingbird biology. With their high energetic demands and delicate sensitivities, hummingbirds rely on keeping their beak open for essential functions. So if you notice a hummingbird with an agape beak, it is likely just going about its regular business of survival!