Hummingbirds are some of the smallest and most fascinating birds in the world. Their unique adaptations allow them to hover and fly backwards, surviving on minimal amounts of food. But what exactly helps hummingbirds survive?
Quick Answers
Here are some quick answers to key questions about how hummingbirds survive:
- Extremely high metabolism – A hummingbird’s heart beats up to 1,260 times per minute, allowing it to flap its wings 70 times per second and hover.
- Nectar diet – Hummingbirds get most of their energy from drinking nectar from flowers. They have extendable tongues to lap up nectar.
- Incredible flying ability – Hummingbirds can fly forwards, backwards, upside down, and hover in mid-air, thanks to specialized shoulder joints and wing adaptations.
- Torpor – To conserve energy, hummingbirds can enter a hibernation-like state called torpor where their body temperature and metabolic rate drop dramatically.
- Camouflage – Hummingbirds’ small size and often iridescent plumage helps them blend into their environments to avoid predators.
- Migration – Many hummingbird species migrate long distances, flying 500 miles nonstop over the Gulf of Mexico. Their need for frequent refueling drives this migration.
Metabolism
One of the most important adaptations that allows hummingbirds to survive is their extremely fast metabolism. A hummingbird’s heart rate can reach up to 1,260 beats per minute while at rest. This allows hummingbirds to flap their wings up to 70 times per second, enabling them to hover in place as they drink nectar from flowers.
Hummingbirds have the highest metabolism of any vertebrate animal. To support this rapid metabolism, hummingbirds must consume a huge amount for food for their size – the equivalent of a person eating 300 hamburgers a day! This intense energy requirement drives hummingbirds’ reliance on nectar and the need to visit hundreds of flowers each day.
Diet
The vast majority of a hummingbird’s diet consists of nectar from flowers. Hummingbirds’ long, extendable tongues allow them to reach deep into flowers to lap up the nectar inside. An amazing adaptation called a “nectar guide” on hummingbirds’ tongues uses capillary action to draw nectar into their mouths as their tongues dart in and out of flowers.
In addition to nectar, hummingbirds get essential proteins and nutrients by consuming small insects such as fruit flies, mosquitoes, spiders, and aphids. They occasionally supplement their diet with pollen and tree sap as well.
Here is a table summarizing the diet composition of hummingbirds:
| Food Source | Percentage of Diet |
|---|---|
| Nectar | 70-90% |
| Insects | 10-30% |
| Pollen, tree sap | 5% or less |
As this data shows, nectar makes up the vast majority of hummingbirds’ nutritional intake.
Flight Adaptations
Hummingbirds have evolved incredible flight adaptations that allow them to fly in seemingly impossible ways. Here are some key flight adaptations that help hummingbirds survive:
- Wings – Hummingbird wings are small but extremely strong for their size. By flapping up to 70 times per second, their wings provide enough lift for these tiny birds to hover and fly in any direction.
- Rotating shoulders – Hummingbirds can rotate their shoulders 360 degrees, allowing their wings to move in a full circular pattern and enabling mid-air hovering.
- Lightweight skeleton – A hummingbird’s bones account for only 4% of its total body weight. Their extremely lightweight skeleton reduces energy required for flying.
- Large chest muscles – Up to 25% of a hummingbird’s weight is flight muscles in their chest. This provides the power needed for rapid wing beats.
Without these anatomical adaptations, hummingbirds could never achieve their signature hovering movements and would expend far more energy during flight.
Backwards and Upside Down Flight
In addition to hovering, hummingbirds can fly backwards and even upside down. Backwards flight allows them to efficiently visit the same flowers multiple times. Upside down flight positions them to feed at flowers above them.
Hummingbirds achieve this versatile flight by rotating their wings in a full circle. No other birds can perform these precise flight maneuvers.
Torpor
To conserve energy when food is scarce, hummingbirds are able to enter a hibernation-like state called torpor. Their metabolic rate drops to one-fifteenth of normal, and heart and breathing rates also dramatically slow. A torpid hummingbird has a body temperature around 60℃F compared to its normal 101-104℃F body temperature.
Torpor allows hummingbirds to save an incredible amount of energy. For example, their nighttime energy expenditure drops from 14.5 calories per hour normally to just 1.3 calories per hour in torpor. Torpor may allow hummingbirds to survive periods of scarcity when the flowers and nectar they depend on are not available.
Camouflage
Many hummingbird species have evolved camouflaged plumage that helps conceal them from predators. Examples include:
- Iridescent feathers – Greens, blues, and other iridescent colors allow hummingbirds to blend into vegetation and sky.
- Underbelly feathers – Belly feathers are often white to match the sky when the bird is viewed from below.
- Patterned tails – Markings and spots on tail feathers resemble foliage patterns.
By camouflaging with their surroundings, hummingbirds can avoid drawing unwanted attention from predators. Their small size also makes them hard to notice. Camouflage works alongside flight adaptations to boost hummingbirds’ odds of evading detection.
Migration
Hummingbirds migrate incredible distances, with some species traveling over 2,000 miles one-way over the course of several weeks. For example, Ruby-throated Hummingbirds fly nonstop over the Gulf of Mexico – a 500 mile journey requiring up to 20 hours of flight.
What drives this strenuous migration? Hummingbirds time their migration to follow flower blooming seasons and take advantage of optimal nectar availability in different regions. As flowers die off in late summer and fall, hummingbirds migrate south to warmer climates where more flowers are still in bloom.
Other factors like lack of tree cover and declining insect populations may also contribute to migration. But access to plentiful flowers and nectar sources is likely the primary reason for hummingbirds’ long migratory journeys.
Fueling Migration
To complete their incredible migratory flights, hummingbirds need sufficient fuel in the form of nectar and insect protein. Here are the key ways they prepare:
- Doubling their weight – In the weeks before migrating, hummingbirds bulk up, increasing body fat stores to nearly double their normal weight.
- Eating constantly – In the days preceding migration, hummingbirds feed nearly nonstop to create fat reserves.
- Timing to flowers – Hummingbirds carefully time migration to coincide with peak flower blooming when ample nectar will be available along the route.
These behaviors ensure hummingbirds have enough fuel in the form of fat reserves to provide energy for hours of continuous flying.
Conclusion
Hummingbirds’ rapid metabolism, nectar-based diet, specialized flight adaptations, use of torpor, camouflage, and long-distance migration all contribute to their incredible survival capabilities despite being the smallest birds. Next time you see a hovering hummingbird, consider the many biological wonders that enable it to survive!
