One possible adaptation that helps them float could be that they are lighter or less dense than other terrestrial birds their size. There could have also been a change in their internal organs that helps them float. They might have more open space inside their bodies to hold air, or some of their organs could be hollow, or at least hollower that other birds’ organs. Being able to hold more air would make them lighter and more buoyant, thus keeping them afloat rather than sinking below the surface. Their feet also might help them stay upright in the water on days when the waves are especially rough. Their legs might move or swim to counter the motion of the water to help fight the desire to flip over. The webbing between their toes could also have been an adaptation to help with floating and staying upright because of the way they move the water away from the bird. Having that webbing can move more water away in a shorter amount of time and can therefore react faster to the ever-moving …show more content…
They have to have strong legs to be able to propel themselves forward into the water. Once they have their head underwater, they have to move their legs around to keep them under long enough to find something to eat. I also think the way the air moves in their body had to adapt in order to be able to dive in the water. If they suppress the air to a certain region of their body, possibly the rear end, they will have less at the top end, and will be able to dive because they are denser. These two birds had to evolve to be able to do these two behaviors, and likely many more. Their evolution could be a result of natural selection. The traits didn’t all evolve at the same time, but they all had to happen at some point. The birds with strong legs and webbed feet would likely have been more successful and would have passed on their genes and traits to the next generation. Only the most beneficial traits will be passed on, and the ones that don’t help with survival will slowly die out. That is why these birds can float and dive into the water for