A crash course on Hummingbirds

Here's EVERYTHING you need to know about them! (Okay, not really. I'm not that knowledgable)

Where do I even begin when it comes to the wonder that is a hummingbird?! When someone brings them up, I’m sure you can already picture the brilliant jewel flitting from branch to branch, hovering in the air as it draws nectar from equally-brilliant flowers.

Image credit: Wild Bird Scoop. Did you know? The very fastest hummingbirds have been shown to achieve an average maximum velocity of 90 feet per second. That’s over 60 miles per hour!

Being able to fly at all is impressive. Flight has evolved in only five recorded instances in separate animals: insects, pterosaurs, birds, bats and humans (done through tool use.) More on this on a separate newsletter!

But hummingbirds take it a step further by being the only bird able to fly forward, sideways, backwards, and even upside down. They are also the only vertebrae capable of hovering for a period of time during flight. In fact, hummingbirds get their name from the humming noise their wings make as they beat so fast.

There are over 350 species of hummingbirds, and today, we’re going to learn about ALL OF THEM! (Kidding! We don’t have enough time for that.) But let’s learn about what makes them so special.

Unlike many other birds, hummingbirds can’t walk

Picture a crow or raven, and you can imagine them hopping around on the ground, or near trash bins. But unlike these birds, hummingbirds aren’t able to walk at all!

For one thing: they don’t have knees! Hummingbirds are a part of the bird order known as “Apodiformes,” which in Latin means “footless”. But they do actually have feet - just, super tiny ones - and no knees.

And for another, hummingbird's legs have evolved to be super small, shriveled up, and weak, so as to require less calories. Their legs are not muscular enough for hopping or walking, and the bones are hollow. None of this is design flaw, though - these birds were designed this way by Almighty God himself. Namaste!

Image credit: Wild Bird Scoop. Hummingbirds have four toes on their short, knee-less legs. Three point forward, and the other one points backward. The toe at the rear is like a human thumb and is commonly called a 'hallux. ' Each of these toes is quite lengthy compared to the length of the legs.

Heavier legs (that rarely get used) would take up more energy, and require a hummingbird to eat more. And since they don’t even need to walk to find food, the effort-to-reward ratio meant that over the course of evolution, hummingbirds evolved to have smaller legs and feet.

Can a 90% sugar diet be good for you?

As a sugar addict, I’ll be quick to say: no way. But somehow, hummingbirds have made it work for them!

Image credit: Earth.com. Hummingbirds occupy a unique place in nature: although they fly like insects, they have the musculoskeletal system of birds. Since they have extreme aerial agility and flight forms, many drones and other aerial vehicles are recently designed to emulate hummingbird movements.

Even though they are one of the tiniest living creatures in the world, hummingbirds keep to an incredibly fast pace of living - in fact, they have a metabolic rate almost 100 times faster than that of an elephant. But while that may sound impressive, it presents a LOT of drawbacks for these tiny, powerful birds.

For one thing, because their metabolic rate is so high, hummingbirds are forced to consume 1.5 to 3x their weight in calorically-dense nectar every day.

Hummingbirds live at the edge of physical possibility. All warm-blooded animals constantly lose heat energy from their surface area, and small creatures lose heat much more quickly because their surface area has a greater ratio to their volume. That’s the the same reason why babies get cold much faster, whereas larger, fatter people tend to stay warmer for longer. Hummingbirds are so small, compared to other birds, that they have to eat more just to stay warm, and alive.

If they were any smaller, it would not be possible for them to eat enough to make up for the heat energy they lose every day. So what happens if they don’t meet their daily nectar requirement?

Simple: they’d starve to death.

As brilliant as they are, hummingbirds are on the verge of starvation at every moment. In fact, to stay alive at all, hummingbirds have to refuel every 10-15 minutes. That means they would never be able to sleep for long periods of time. If they slept (and stopped eating when sleeping) they would die!

If they sleep, they die. So how do they rest?

Every night, hummingbirds enter a state of rest that’s somewhere in between sleeping, and death. It’s called torpor, and it is the hummingbird version of hibernation (although some other animals practice torpor, too!)

Image credit: Birds and Blooms

What is this, and what does this state of torpor do to their bodies?

Well… I don’t mean to be a killjoy, but I’m going to save the post about torpor for next week’s article. It’s not that I’m lazy to write about it! The topic is just so interesting I want more time and words to dedicate to it. :P

But in the meantime, you can think of torpor like hibernation - sort of. Some animals can enter ‘daily torpor’ for a few hours, but hibernating species remain torpid for days or weeks. Although often described as ‘multi-day torpor’, a hibernation period will also include cycles of sleep and wakefulness, and it’s unknown whether the torpid phases are exactly the same as daily torpor.

Image credit: Discover Wildlife. Some animal species enter a state of suspended animation that is called ‘torpor’. And while it might look like torpid animals have just gone to sleep for a while, they’ve actually undergone profound physiological changes that include a dramatic drop in their body temperature.

More on torpor in next week’s post: if hummingbirds die if they slept, how do they get any rest?