Fine. I’ll do a #nerdy9th
post about birds and flight if I must
I will note, however, that I am doing this under protest and was originally going to write about something else entirely but whatever
Alright, so the principles of flight are relatively simple even if they are mechanically a lot more complicated than they originally appear. I mean, there’s a reason we have an entire field called aerodynamics and aeronautics. This shit is harder to replicate than it looks. And birds do this effortlessly.
I mean, I guess if you consider evolution since the Jurassic period to be effortless, then sure.
But wings are fucking fascinating.
See, it’s not just that birds had to undergo a series of evolutionary steps that involved not flying at all to probably gliding to actual powered flight. It’s that there are now quite a number of different kinds of wing designed to do quite a different number of things. I was originally just going to keep ranting about all the different basic styles of wings, but today is going to be broad wings. Listing all of the wing types and explaining them just takes too long. You can find these wing shapes in other groups of birds, but I’m using their representative groups for a reason, which is mostly because it’s easier to see why broad wings are useful and what they are useful for without nit-picking about exactly which bird species use these.
First, you’ve got heavy, large bodied waterfowl. These kinds of birds are mostly designed for swimming and spending a lot of their life on water and diving for food. Their wings are, relatively to their body mass and size, broad but about middling in length (this will make more sense in context when you read the rest of the post). Since they have to be able to take off from water, where their bodies and wings sit very close to the waterline, large waterfowl have to take a run at it to get into the air, wings pumping furiously to generate the force required to first lift their heavy bodies out of the water, then actually start flying. When you see a goose take off from the water, they are making quite the fuss and then once they actually get out of the water, their wings stabilize, they glide, flapping lazily to gain altitude and speed. All the strength in a goose or swan’s wing is designed to overcome the problem of taking off from a liquid, even while they paddle madly with their feet for that extra bit of forward thrust. They have to create air space between themselves and the water surface generate the lift they need and they need more lift than land birds because pulling themselves out of the water is hard.
On top of that, most of the large-bodied waterfowl then migrate for days or weeks at a time across two continents. So those broad wings also have to be good for long flights, which is why they’re of middling length. All that body mass? Yeah, it’s so that the birds actually have the energy to sustain those long migratory flights.
You know who else have broad wings? Short, fat, chicken-birds. The galliformes
, an incredibly terrestrial order, aren’t really aerodynamic on the face of it. They don’t typically migrate and they are way better at running and hiding than they are at flying away so they don’t need large wings. So their short, stubby, broad wings are designed pretty much for one purpose. To launch them into the air at high velocities, cause everything within two meters to have a heart attack, and get them out of danger. Those short stubby wings are supremely excellent at taking off from a standstill. They don’t need to run to get speed, heck, they can take off while buried under the snow
. That comically round body shape is almost entirely wing muscles attached to a large keel bone so that in that moment where the coyote is about to pounce, the grouse can suddenly just not be there. It’s energetically expensive to fly and fatbirds just don’t want to do it. So they store all that energy for rapid takeoff to escape danger, but they can’t sustain it for very long.
You can even hear how badly designed their wings are for anything other than powerful, sudden escape flights. The wings thrum and beat loudly, catching and battering the air. It sounds like an explosion if you are unfortunate enough to nearly step on a grouse. Sure, some of the Order can actually sustain flight for some time, but it’s not their specialty. Their wings are sharply curved downwards with stiff, unyielding primary feathers.
Then we get into the last category of broad-winged birds. Soaring on thermal air currents is wonderfully energy efficient, which is great if you need to spend all day looking for food that you maybe don’t want to waste just to find more food. These broad wings are nearly flat compared to the large-bodied waterfowl and partridge style wings. The birds themselves usually live in trees so taking off just requires falling and not hitting the ground, so their wings don’t need to be designed for the heavy work of taking off. Since they still need to take off from the ground, however, the broadness still helps. But if you’ve ever watched a hawk take off from the ground, there’s a bit more flailing and often running involved than the suddenness of a grouse.
Broad wings are mostly designed for take-off. But buteos
and other soaring birds modified the broadness. They are certainly no slouches when it comes to taking off, but their wings are too long for it to be as efficient. The wings are long and broad, their bodies relatively small compared to their wingspan, the feathers softer and much more individually pliant.
But in all three cases of this kind of broad wing, the feathers are splayed out to better catch air, to maximize surface area and keep the birds aloft.
And now I’ve written a thousand words about bird wings. Gee thanks internet