We marvel at birds in flight.
But one kind of bird stands apart in
its acrobatic talents, with a complex
flight system unlike any other.

Picture yourself relaxing in the
floral bouquet of a butterfly
garden when suddenly the buzz
of a gigantic bee tingles your
ears, followed by an explosion of
brilliant color. Then, as quickly as
it disrupts your peaceful world,
the UFO vanishes without a trace.
After the shock passes, it dawns
on you. You’ve just witnessed one
of the greatest shows on earth.

No, Barnum and Bailey had
nothing to do with it, and this
wasn’t a close encounter of an
alien kind. You have encountered
one of the most amazing and
mysterious birds on the planet!

The hummingbird may be one of the most well-known
birds on earth, yet this colorful acrobat continues to mystify
the greatest mathematicians and aeronautical engineers.
Just when they think they’ve learned all there is to learn
about these birds, they discover more.

Hummers differ greatly from other birds. While most of
their feathered friends fly by thrusting forward like jets,
these aerialists can stop on a dime, hover, somersault, fly
backward, and even fly upside down. No other creature
can match their skills. And man-made craft don’t compare.
(What helicopter can cross the Caribbean Sea on a half
ounce of fuel?)

Only the skill of an all-knowing Creator and Engineer
could explain all the integrated systems necessary to make
such flight possible. It’s a package deal, not something that
could arise piecemeal by trial and error.

Hovering Ain’t Easy

Bird flight is arguably the pinnacle
of God’s design in the animal kingdom.
For millennia, humans have
marveled at the wonderful traits
shared by birds—their aerodynamic
bodies, flexible feathers, and ultralight
building materials. Yet hummingbirds
are special, even among birds. Some
say they’re the pinnacle of God’s pinnacle
of animal design.

They perform a rare role among
birds—pollinating flowers—which requires
hovering. Like large insects,
they must be able to hover at the end
of long flower stems and insert their
long bills and tongues to draw out nectar.
No other bird lives this way; other
birds simply grab food “on the go” or
perch to eat.

We admire eagles and swallows for
their power and grace, but they can’t
hover. Their wings must constantly
move through the air or they will stall
and crash. Fixed-wing planes can’t
hover, either, for the same reason. The
only way helicopters can perform this
wonder is by a complex combination
of designs that channel the engine’s
energy to turn a rotor with blades that
create their own controlled airflow
(like a mobile fan pointing downward).

How do hummingbirds create their
own airflow without spinning blades?
The answer isn’t simple. In fact, we
still don’t understand it all. But one
thing is clear, everything about the
hummingbird must be perfectly balanced
to achieve maximum airflow at
minimum cost. Somehow, hummingbirds
solve a host of engineering problems
that boggle the mind.

High-Octane Featherweights

The challenge begins with size.
What’s the optimum size for hovering?
Well, you’ve never seen a hummingbird
the size of condors or eagles.
There’s a good reason for this. You
can’t stick twirling blades on top of
birds, so you have to go small. And
hummingbirds are the king of small.

Hummers are the avian featherweights
in the truest sense. They have
the smallest length of any bird (Cuba’s
bee hummingbird is only 2.5 inches [6
cm] long) and the lowest weight (the
average male ruby-throat weighs 0.1
ounces [3 g]).

Their need for lightness extends
to their eggs. Female hummingbirds
can’t afford to carry around unnecessary
weight. So they lay the tiniest
eggs of any bird, smaller than a jellybean
(0.5 inches [1.2 cm]). And they
usually lay only two per clutch.

While minimizing size and weight,
hummingbirds also have a voracious
appetite for fuel to keep their “fan”
blowing. Though small, they still need
to travel fast and cover long distances
in search of food, to avoid large predators,
and to find safe breeding ground.

Rufous hummingbirds hold the
world record hummer migration distance.
Each year they fly an unbelievable
3,900 miles from their wintering
grounds in Mexico to their nesting
grounds in Alaska or Canada! On these
trips, they travel at an average speed
of 30 mph (50 km/hr.) and consume as
much as one-half their body weight in
fuel per day.

Rufous Hummingbird

The rufous
has the longest
migration of any
species. These
hummers fly
more than 3,000
miles from their
nesting grounds in
Alaska and Canada
to their winter
habitat in Mexico.

Seeds are too inefficient to carry
around in their stomachs to meet
these high-energy needs. This power
source would be like fueling a jet with
a wood stove.

The secret to their success is a
high-octane fuel: the sweet-smelling
nectar that tube-shaped flowers produce
just for this occasion. The sugar
is converted to flight energy with
97% efficiency—a real winner in the avian world. By God’s
design, they can find this refined fuel virtually anywhere,
like a gas station at every corner, ready 24/7 to supply the
hummingbirds’ needs.

And their needs are great. Active hummers must feed on
this nectar five to eight times per hour, though they are not
opposed to an occasional snack of insects and spiders.

Engines require more than just fuel. They need oxygen.
Lots of it. Birds get their oxygen through their lungs, where
it is transferred into their bloodstream by rapidly beating
hearts. (Bird lungs aren’t like any other creature’s lungs, but
that’s a different story.) With hearts aflutter at an astounding
1,200 beats per minute, hummingbirds have the highest
inflight energy and oxygen requirements of all birds. Even
at rest, they breathe 250 breaths per minute, and this rate
increases dramatically when they jet out! This rapid oxygen
intake enables them to generate flapping rates of 10 to 200
beats per second, depending on the species and flight circumstances.
(Can you see a hawk doing that?)

Crazy Eight Flight

Bird aviation of any kind is complex.
It’s so complex, in fact, that mathematicians
have not yet worked out
the numeric details. Add to the equation
hummingbird acrobatics, and the
mathematical complexities skyrocket!

Most birds fly with a relatively simple
up-and-down motion. Hummers,
by contrast, rely on three basic types
of wing motion: up-and-down motion
to move forward (like other birds),
spinning motion overhead to move
backward, and a “figure eight” motion
to hover (see graphic).

Hummer Helicopter

Hummingbirds have more
flight abilities than other
birds. Like a helicopter,
they can hover, fly sideways
and backward, and even do
backward somersaults as
they dart among flowers
searching for nectar and
insects. Most bird wings
bend in the middle, but
hummingbird wings are
rigid. A special shoulder
joint allows them to
pivot their entire wings
180 degrees, giving them
options other birds (and
helicopters) don’t have.



Illustration by Katie Compton

Like other birds, hummingbirds fly
forward with a constant downstroke.
They can maintain impressive speeds
of 30 miles per hour.



Illustration by Katie Compton

Hummingbirds fly backward
simply by rotating their wings so that
each stroke is over their heads. They
can fly just as fast backward as forward,
and without expending extra energy.



Illustration by Katie Compton

The hummingbird’s hovering motion is
possible because it can rotate its wings
in a figure eight. In this way, both the
forward and backward stroke push down.

The ability to hover is the most
amazing of all. Other birds produce
thrust only on their downstroke.
They bend their “wrist” and “elbow”
in the middle of the wing to make
subtle changes during the downstroke,
but they can’t push air during
the upstroke. Hummingbirds, in contrast,
can pivot their entire wings at
the shoulder, producing thrust on the
upstroke, too.

How do they do this? A unique ball-and-socket joint in their shoulder lets
them rotate their wing instantly in
either direction—up to 180 degrees!
This allows them to constantly push
the leading edge of their wing through
the air, even on the upstroke. The
crazy-eight motion also moves the
wings through more air, increasing
their efficiency.

The hummingbirds’ pivoting wings
allow them to remain stable while hovering,
without bouncing up and down.
And this design explains how they can
change directions at the drop of a hat.
With slight variations in their figure
eight, they can also slide sideways and
do other acrobatics.

Their flight abilities have been compared
with dragonflies rather than
other birds. In fact, when Europeans
first discovered them in the New
World, some thought they were a cross
between insects and birds! Hummingbird
wings are stiff like an insect’s
wings (although they can still bend them in the middle,
enabling them to do some tricks insects can’t). Their flapping
creates complex vortices in the air, which we are still
trying to understand. That’s what allows huge bumblebees
to fly with such short wings. Hummingbirds take advantage
of these invisible forces to increase their lift, too. They don’t
just beat their wings harder; they optimize forces of physics,
which we can only now begin to understand with the help of
advanced computers.

Everything in the hummingbird is carefully balanced to
maximize flight power and minimize weight. Their powerful
chest muscles take up 25–30% of their body weight, more
than any other bird. In this complex tradeoff, their legs and
feet are extremely small; so small, in fact, that they can’t
walk. They can only perch and hop sideways on branches.
This seeming disability is not a disability at all, but is
important in cutting down drag during flight.

Wired for Aviator Acrobatics

Imagine what it takes to control all these interrelated systems
at super speeds. Two separate wings constantly rotate
and flip, sometimes at different angles and speeds during
special maneuvers. The tail and other body parts counterbalance
every wing motion to keep the body perfectly
stable while hovering. Meanwhile,
firing electrical signals regulate the
fastest beating heart on the planet.
The eyes must constantly process a
visual field that changes dramatically
in three dimensions. And on it goes.

Intense research, published this
year, has looked into the hummingbird
brain to see how all this is possible.
Specifically, researchers have looked
at the region known as the lentiformis
or LM for short. This is
the part of the brain designed to detect
the hummingbird’s motion relative to
its surroundings.

Green-Crowned Brilliant

The green-crowned
brilliant resides
in the highlands
from Costa Rica to
western Ecuador.
Unlike many other
hummingbirds, this
gem almost always
perches to feed.

Most birds and mammals primarily
detect their motion visually in one
preferred direction, from back to front
(the direction they usually move). But
the hummer’s LM is bigger than other
birds’, and it can perceive its own
motion precisely and equally well in all
directions, especially at high speeds.

The research suggests that hummers
can even correct for very slight
drift when hovering. In fact, the scientists’
overall conclusion is that their
brain is designed for flight!

Engineers can only marvel at such
complex systems within systems
within systems that make hummingbird
acrobatics possible (from the programming
of the cell chemistry that
builds and runs cells, to the tissues and
organs and organ systems that “talk” to
each other and coordinate flight). For
believers in Jesus the Christ, this conclusion
is consistent with the scripture
where God said at Creation, “Let birds
fly above the earth across the expanse
of the heavens
” (Genesis 1:20). Such
integrated technologies wondrously
declare the glory of the Creator.

Overcoming Challenges of a Fallen World

When God created birds, suffering and death were not a part of this
world. Now every creature, including hummingbirds, must survive the
ravages of an environment that’s off kilter. Yet God made sure hummers
were ready for the challenge. Their speed and agility make them fearless,
even against large predators. They are notoriously aggressive, chasing
away hawks and other threats without hesitation because they know
they can outmaneuver them!

God has endowed them with other onboard equipment necessary to meet
the challenges that the natural world can throw at them. One of the most
significant dangers is cold weather at night.

Many hummers live in places where temperatures drop below freezing
at night. Many also live at high elevations, such as the Andes Mountains,
where limited oxygen puts an added strain on their high-energy system.
Without a constant input of fresh fuel, they would burn all their reserves
and perish within an hour or two.

But our God has designed them to lower their body temperature and
decrease fuel consumption by 95% at night. This is known as a torpor,
sort of like a short-term hibernation.

The hummingbird is a visual reminder that God gives life and cares for his
creatures, in spite of sin and its effects. His creation is meant to redirect
our gaze back on him (Romans 1:20). The hummingbird reminds us of his
infinite intelligence, his engineering creativity, his all-surpassing beauty,
and most importantly his loving provision.

May the complexity and the mystery of the hummingbird be a reminder to
all that God exists, that he wishes to be known, and that he offers eternal
life to everyone who calls upon the name of his Son, Jesus Christ.

Jesus himself reminds us, “I tell you, do not be anxious about your life,
what you will eat or what you will drink, . . . Look at the birds of the air: they
neither sow nor reap nor gather into barns, and yet your heavenly Father
feeds them. Are you not of more value than they?
” (Matthew 6:25–26).

Tom Hennigan is associate professor of biology at Truett-McConnell University, where he teaches organism biology
and ecology. He is coauthor of the newest edition of the
Wonders of Creation series, The Ecology Book.

This post was originally published on this site