I’m at the shore watching gulls and terns circling and gliding over very choppy water in windy conditions. Even standing on a pier and looking straight down, I can barely see into the water. Yet, every so often, one of the birds will make a dive and come up with a shiner in its beak. Anyone know what talents, abilities, skills, etc. they use to allow them to even see these all but invisible prey? How do they do it?
Keen eyesight, excellent timing and a lot of practice. If the wind is right they can hover a few feet off the water for quite a while and wait until something interesting approaches the surface from below…
I guess a boy who’s grown up with dolphins would know… any bad bird memories in your past you aren’t telling us??
I guess I’m asking for something a bit more specific. After all, I have pretty good eyesight, but I can’t discern a flashing fish from a wave on a choppy surface. What type of visual discrimination is required for them to do that, while in motion?
I can’t find a paper on the visual acuity of sea gulls, but remember that when they aren’t picking through our garbage they are evolving in a natural habitat that requires them to find food under less than perfect circumstances. And being able to differentiate between a fish and some random sea foam in stormy seas from 6 feet up is a skill they would need to survive.
How do they do it? Their brains are wired to pick up subtle clues we can’t perceive. Need more detail than that? Then we need an expert in the field of avian brain anatomy…
I suspect that altitude has something to doe with it. Aren’t aircraft better at spotting submarines just below the surface than ships? I seem to recall reading that they are, but can’t cite.
Many years ago I worked training dolphins at a marine park in California and we had a real problem with sea gulls. We would hang a fish on a pole for the dolphins to jump out of the water and grab, but the sea gulls would dive bomb and steal the fish during the show. They didn’t have any fear and would fly into our fish house to steal a fish out of the sink. We called them “flying rats”…
I think this may be getting at something more significant. I’ll stay tuned. Paging Colibri.
I read that a Orca learned it could regurgitate the fish the trainer’s fed it, then the gulls would fly in to get it, then the Orca would eat the gulls.
I sometimes wonder if it’s practice. I’ve seen herons and such and they will stand around for HOURS looking for a fish. Maybe they have more patience than humans. If the water is choppy we give up but the birds keep looking and their eyes adjust to the choppiness.
Along a different idea, my guess is that shorebirds and such have a different visual spectrum compared to humans… so whereas we would look at the water see lots of noise mixed in with what we want to see, birds’ eyes may automatically filter out the useless information, as learned over many generations of “fishing”.
The book series “animorphs” actually had a nice spiel about it… no word on whether it had any actual basis in truth or not.
As was eluded to above. You are looking through the world with your own perspective. The angle you are viewing the water makes it difficult to see under the surface. But if you are looking straight down from a higher altitude you will be able to see things better underwater.
Look at a clear lake or ocean from a plane, you can see the bottom for quite a depth, but you can’t discern the bottom looking at an angle from a boat, even on a ripple free day.