---
title: 'How High Can Birds Fly?'
source: 'https://youtube.com/watch?v=fPHVuxOsvI8'
video_id: 'fPHVuxOsvI8'
date: 2026-06-28
duration_sec: 414
---

# How High Can Birds Fly?

> Source: [How High Can Birds Fly?](https://youtube.com/watch?v=fPHVuxOsvI8)

## Summary

This video explores the biological and aerodynamic limits that determine the maximum altitude a bird can achieve. By analyzing oxygen availability, heat retention, and lift generation, the presenter combines theoretical calculations with observed data to estimate the highest-flying bird species.

### Key Points

- **Historical Collision** [0:00] — In 1973, an airliner struck a Ruples Griffin vulture at over 11,000 meters, far above typical bird flight altitudes.
- **Two Limiting Factors** [0:46] — A bird's maximum altitude is constrained by its ability to stay aloft as air pressure decreases and its ability to survive as temperature and oxygen levels drop.
- **Survival at Altitude** [1:07] — Oxygen efficiency and heat retention are key; larger birds generally have higher 'popsicle points' (hypothermia threshold), with the wandering albatross potentially surviving up to 17,000 meters.
- **Aerodynamic Lift Limit** [2:17] — Less dense air at higher altitudes reduces lift; smaller birds tend to have higher lift limits, with the sand martin potentially gliding at nearly 19,000 meters.
- **Combined Analysis** [3:56] — Birds must balance survival (popsicle point) and lift (lift limit); geese like the bar-headed goose show high potential, matching observed migrations over 7,000 meters.
- **Top Predicted Flyer** [4:45] — The white stork theoretically could fly up to about 10,500 meters based on its popsicle point and lift limit.
- **Real-World Exception** [5:01] — The Ruples Griffin vulture, known to exceed 11,000 meters, does so by riding thermals (rising warm air), surpassing its calculated lift limit of ~8,200 meters.
- **Likely Highest Flyer** [5:40] — With optimal thermals, the Ruples Griffin might reach its popsicle point of 15,000 meters, making it the bird capable of the highest flight.

### Conclusion

While theoretical calculations suggest that birds like the white stork could reach up to 10,500 meters, real-world observations show that the Ruples Griffin vulture, aided by strong thermals, is likely the highest-flying bird, potentially reaching 15,000 meters. Birds don't always fly as high as they physically can, but the combination of biology and aerodynamics explains their altitude limits.

## Transcript

In 1973, an airliner struck a bird
called a Ruples Griffin vulture, which
on its own isn't that weird. Planes hit
birds pretty regularly during takeoffs
and landings. But this collision
happened at a cruising height of over
11,000 m. That's way above the height at
which most birds fly, which it makes me
wonder, what is the highest a bird can
actually fly. Hi, I'm Cameron and this
is Minute Earth. Birds don't tend to fly
higher than they absolutely need to for
the same reason you don't sprint when
you could walk. It's difficult and
tiring. So, we can't necessarily get the
answer to this question through
observation. I mean, I guess we could
drop a bunch of birds out of airplanes
and see what happens, but our AdSense
revenue definitely isn't going to cover
that. Plus, we're not monsters. So,
let's use our understanding of
aerodynamics, scaling laws, and biology
to science our way to an approximate
answer. There are two things that limit
how high a bird can fly. Its ability to
stay aloft as the air pressure
decreases. And on a much more basic
level, its ability to stay alive as the
temperature and amount of oxygen
decreases. So, first, let's figure out
which bird could survive at the highest
altitude. Oxygen supplies birds the
energy they need to stay warm, but at
higher altitudes, there's less oxygen
available and the temperature is much
colder. So, a bird's ability to survive
high up in the air depends on how
efficiently they use oxygen and how well
they can retain body heat. This paper
measured the oxygen use of a handful of
birds and found that very generally
their overall oxygen use increases with
mass. We can then adjust according to
other traits like how much energy their
flight muscles require and how much
insulation their feathers provide. From
all of this, we can calculate the
altitude at which each bird should
suffer from hypothermia. Let's call this
their popsicle point. If we then compile
a data set of flying birds and plug
their data into these equations, we can
see a general pattern emerge. Larger
birds can theoretically survive at
higher altitudes than smaller birds.
There are exceptions, of course. This is
biology after all, but our calculations
suggest that there are a bunch of birds
that could potentially survive above
10,000 m. And the largest bird in our
data set, the wandering albatross, might
be able to survive as high as 17,000 m.
But remember, we also need to figure out
if any of these birds could actually
stay aloft at such high altitudes.
Because the air is less dense the higher
you go, less air is available at higher
altitudes to push upward against a
bird's wings and create that lift. A
bird's ability to stay a loft high in
the air depends on its weight, size of
its wings, and the shape and angle of
attack of its wings. That's a factor
called the lift coefficient. Combining
all of that tells us how much lift a
bird's wings should generate in still
air at a given altitude. Simple enough
at first. Uh, but while weights and
wingspans and whatnot are easy enough to
measure, the wing shapes and angles
aren't because a bird's wing shape
changes as it flies. I'll save you the
long explanation of my rationale here
and just say that this is about where I
go out on a bit of a limb. The lift
coefficient for the birds in our data
set peaks at about 1.5 or so, and that's
when they're taking off or about to
stall. In other words, when the bird is
trying hardest to generate lift. And
since staying aloft is likely a struggle
at a bird's maximum altitude, this is
probably a pretty good estimate of the
lift coefficient at this point. From
there, we can find the lowest air
pressure at which each bird could
generate sufficient lift to keep its
mass aloft. And then use our friend, the
barometric equation to convert those
numbers to altitudes to estimate the
highest point each bird in our data set
should be able to actually maintain
flight. Let's call this their lift
limit. In general, the smaller birds
have the highest lift limits. The
hulking mute swan would struggle to
generate lift at a mere 3,800 meters,
while the puny sand martin should be
able to glide at nearly 19,000 m. Of
course, air moves and it's not uniformly
dense at given altitudes, so there's
definitely some wiggle room here, which
will be a surprise tool that's going to
help us later. But in any case, a bird
with a higher lift limit should be able
to fly higher than a bird with a lower
one. Now, let's combine our lift limit
data with our popsicle point data. We
can see that lots of birds like the
missile thrush can theoretically fly
super high but would freeze long before
they got there. And then there are a
bunch of other birds like the wandering
albatross that could likely survive at
super high altitudes but wouldn't be
able to actually maintain flight up
there. That leaves us with a small
cluster of birds with relatively high
popsicle points and high lift limits.
Mathematically, these should be the
highest flying birds. And for the most
part, they're geese. The grey lag goose,
the bean goose, the Canada goose, and
the barheaded goose should be able to
fly as high as 8,000 meters or so,
according to our calculations. And this
matches up pretty well with what
scientists have actually observed. Like
during its migration over the highest
mountain range on the planet, the
bar-headed goose can reach altitudes of
over 7,000 m. And then there's the white
str, which based on its popsicle point
and lift limit, is our predicted highest
flying bird. It could potentially fly up
to about 10,500 m. In reality, it
doesn't fly anywhere near that high. But
remember, birds don't necessarily fly as
high as they might be physically capable
of. But wait, what about the Ruples
Griffin? A bird we know for a fact can
fly higher than 11,000 m. Our math
suggests that it is lift limited a lot
lower than that, about 8,200 m. But this
is where theoretical calculations fall
short without some additional real world
knowledge. See, the Ruples Griffin likes
to soar on thermals, warm columns of
rising air that can help birds exceed
their mathematical lift limit, sometimes
even thousands of extra meters up into
the air. Other birds are also known to
ride thermals, but none of the other
high popsicle point birds ride such
supercharged thermals. So, the Ruples
Griffin is likely the bird capable of
the highest flight. With the right
thermal, it might even reach its very
generous popsicle point of 15,000
meters. Turns out that bird might have
had a lot of climbing left to do.
You might have noticed that this video
is chalk full of all sorts of
calculations that I basically ripped my
hair out trying to make sure I got
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