A topic of conversation this week between friends. A very ordinary picture taken on Monday morning, dense fog, so very surprising, that as with every single morning, a bird should still take his place at the top of this tree.
With virtual invisibility. is force of habit so engrained over common sense? A puzzle, so the question was posted on facebook. Back came a very interesting response.
“Birds sense of vision is very different. They will pick up ultra violet too. Humans have a very, very limited visible spectrum.” Amazing answer. This was from my own son, naturally I thought I couldn’t leave that to chance. And then I found the following:
“…..some species of birds, do take at least some of the day “off” and do not go out to search for food in the fog. (but)… some of those birds may look like they are taking it easy, but may have been up before dawn and have already done their early morning feeding–fog or no fog. They may just be hunkering down to relax during a time when they know it is more difficult for both them and their predators to be out flying and looking for food….
On the whole, birds have much better vision than humans do. Many kinds of birds have the ability to see much greater detail than we do with the ability to see into the ultraviolet range of light…. Others have retinas that are set up with the different colour-sensing cones placed differentially such that they see certain colours best when looking upward, other colours best when looking down, and still another altered range of colours when looking sideways. Many birds can see through the fog as if they were wearing blue-blocker sunglasses and can easily navigate in all but the most dense of fogs.
Many birds do not travel very far to search for food. These birds know their local area as well as you know how to walk through your own house at night. With the barest of clues, they could almost fly from place to place in their neighbourhood while blindfolded. The fog is a bit of an impediment, but not one that will stop them from going out to forage for food and water”
Never thought that such a grey picture would be that interesting. And a source of great pleasure through that very satisfying feeling when your children stretch your understanding not only of the world, but of them. “Relaxed efficiency”. Grey days will never be the same. Just brilliant.