How does a hummingbird’s heart beat so incredibly fast?
Hummingbirds are truly astonishing creatures. It’s no wonder that people love them so much! Even though they only weigh a few grams, these tiny birds make up for it in personality, acrobatics, and interesting behaviors.
One of the most interesting things about them is how active they are. They can hover midair, dive acrobatically toward the ground, fight with other hummingbirds, and even fly backward. With all of this activity, their little hearts work really hard.
A hummingbird’s heart beats between 500 and 1200 beats per minute, based on what they are doing. That means their hearts beat up to 20 times each second!
It’s this very fast heartbeat that enables a hummingbird to perform its unique capabilities. However, sustaining these high heart rates also requires specialized adaptations to their physiology and diet. Let’s explore the incredible cardiovascular functions that allow hummingbirds to hover, dart, dive, and thrive!
How Fast Does a Hummingbird’s Heart Beat When Active?
A hummingbird has the fastest heart rate of all animals relative to their body size. At rest, their heart still beats remarkably fast at about 250-500 beats per minute, allowing oxygenated blood to circulate when they are inactive. But during flight, their heart rate accelerates dramatically to meet their intense energy demands.
When hovering in place, a hummingbird’s heart pumps at up to 500 beats per minute, providing the immense power required for sustained hovering. The wings beat up to 80 times per second to generate enough lift to keep their small bodies suspended.
Forward flight requires even higher rates, with the heart beating up to a staggering 1,200 times per minute when darting between flowers. For comparison, this is higher than the maximum heart rate achieved during any activity by most other small bird species.
All of this tremendous cardiovascular output enables the hummingbird’s unique flying abilities, but as you can expect, supporting these high rates places extreme demands on their oxygen and energy intake.
How Fast Does a Hummingbird’s Heart Beat at Rest?
When a hummingbird is at rest, its heart rate slows down significantly but is still remarkably fast compared to other animals and birds. At rest, the hummingbird’s heart continues to beat at around 250-500 beats per minute.
Examples of other animals’ heartbeats, according to the Merck Veterinary Manual:
|Rhesus monkey (anesthetized)||160–330|
Always pumping at a rapid rate allows oxygenated, nutrient-rich blood to circulate through the hummingbird’s body even when they are not actively gathering nectar, chasing insects, and defending their territory from other hummingbirds.
This ensures their tissues continuously receive the oxygen and energy they need to sustain their high metabolism. The continuously rapid heartbeat also means the hummingbird is essentially always ready to take immediate flight if needed.
What Is Torpor?
We can’t talk about hummingbird heart rates without talking about the fascinating characteristic of torpor.
Torpor is a hibernation-like state that hummingbirds can enter to conserve energy in times of scarcity. When food sources are limited, such as overnight or during seasonal shortages, hummingbirds reduce their metabolic rate and heart rate dramatically by entering torpor.
This allows them to save energy when they do not need to be actively feeding.
During torpor, their metabolic rate also drops and body temperature decreases. This torpid state lasts as long as necessary until morning or until food availability increases again. Torpor is an essential adaptation for hummingbirds, allowing them to survive periods that might otherwise require more energy than they could obtain.
So…How Slow Does a Hummingbird’s Heart Beat During Torpor?
During torpor, a hummingbird’s heart rate plunges down to just 50-180 beats per minute. That is obviously a massive decrease from their typical resting rate of 250 beats per minute and active rate of up to 1,200 beats!
The markedly slower heartbeat during torpor allows a hummingbird to conserve a tremendous amount of energy. This minimal energy expenditure during torpor is what allows them to endure overnight fasts or periods of food scarcity that might otherwise prove fatal.
Their body temperature also decreases significantly, sometimes plummeting as low as 65°F compared to their normal temperature around 105°F. This reduced physiological activity requires far less energy, allowing the hummingbird to persist on limited reserves. The torpid state continues until the hummingbird awakens and resumes its normally rapid heart rate and metabolism.
The Big Takeaway: Hummingbirds’ Tiny Hearts Beat FAST
Here’s the takeaway: A hummingbird’s incredibly rapid heartbeat, which can exceed 1,200 beats per minute, is one of their most astounding physiological adaptations.
Their cardiovascular system powers their unique capabilities including sustained hovering, flying backward, and maintaining an extremely high metabolism. Essential adaptations like torpor also allow hummingbirds to conserve energy when needed by dramatically slowing their heart rate.
Next time you see a hummingbird buzz by, remember that its tiny heart is beating over 20 times every second! To power this nonstop activity, hummingbirds need frequent access to energy-rich food sources.
Providing hummingbird feeders and plenty of nectar-bearing flowers in your garden will help attract these captivating creatures. Watching iridescent hummingbirds hover and dart around your yard is a delight that never gets old!
Here are some of our recent articles about feeding hummingbirds!
- How Often Do Hummingbirds Eat?
- When Should Hummingbird Feeders Go Out?
- How Do Hummingbirds Find Feeders?
- How to Fill a Hummingbird Feeder
Tips for Feeding Hummingbirds
Here are some tips for attracting hummingbirds to your yard:
- Provide nectar feeders with 1 part sugar to 4 parts water solution. Never use food coloring, honey, or artificial sweeteners.
- Choose bright red or orange feeders that attract hummingbirds. Avoid glittered or decorated feeders.
- Refresh the nectar every 2-3 days, or daily in hot weather, as that is when it spoils faster. Rinse feeders thoroughly before refilling.
- Plant plenty of native flowers with tubular blooms like honeysuckle, trumpet vine, bee balm, and sage. Supplement feeders with fresh edible flowers like nasturtium, fuchsia, and impatiens to provide more nutrients.
- Position feeders in shady areas out of direct sunlight to prevent nectar from overheating and spoiling. Space them apart from each other to avoid territorial behaviors at your feeders.
- Avoid using pesticides or herbicides near feeders or flowering plants that hummingbirds may visit.
- Place feeders near trees, shrubs, or other perches where hummingbirds can rest between feeding.
- Hang multiple feeders around your yard to reduce crowding and allow more birds to feed.
- Provide a water mister or dripping fountain for hummingbirds to bathe and drink. Use a shallow basin