When I made my art for the surface of Refuge, I added in birds without thinking. Would birds be practical on a world with 1.16g? Or would they become, in essence, all just chickens flapping nearly useless wings for a few dozen meters of pretend flying?
I think the saving grace for birds on Refuge would be the denser atmosphere. 1.5 times Earth pressure at sea level. Why do I think that would be a saving grace?
When a bird flaps its wings, it is pushing against the air to lift a solid object (the bird) into the air. The effects the bird is trying to overcome include the fluidity of the air, which simply wants to flow around the wing. Feathers are the way they are so that they create “roughness”, or drag, which causes air to stay under the wing long enough to be pushed against. The force needed to lift a few pounds into the air must be held by the air long enough for the bird to get into the air and climb higher. That force would be even greater on Refuge.
A huge amount of the effort the bird expends would be to move the wings fast enough that the lift is created before the air sloshes out from under the wings. In an atmosphere that is 1.5 times as dense, that force would be significantly less because even as air sloshes out, there is still more air left to push against than there is at the pressure of our atmosphere. There are a few minuses, such as the bird pushing harder to move the air above out of the way as well. But the bonus of a thicker atmosphere would, in my amateur opinion, be more than enough to make up for 16% increased weight.
I’m not going to do the phsyics, oh no. I’m not about to spend days on all of those variables just so I can have birds in my book. Instead, I’ll just put them in and believe I’m right. 😉 But it’s my very strong hunch that birds exist on Refuge as they do on Earth and the physics of it would be perfectly viable. In fact, birds might have an easier time on Refuge than they do on Earth. Lift might be far easier to generate. If anyone cares to prove me wrong, I’d love to see that math.