To see or not to see

White-necked Ravens up Kilimanjaro

It's with great consternation that I didn't see these ravens with much interest. I think they were around the 16,000 feet level and I was probably more interested in pulling out another breath. Nevertheless, my fascination with corvids came later. Will it always be the case that my interest soars once something is no longer available such as the exotic and diverse African birdlife like these ravens, Corvus albicollis? Yet maybe the ravens were beginning to work on my unconscious.

Which brings me to Grog in the fog. This morning, despite the fog, Grog found me on the beach while Sunshine was stuck in the nest. As he was standing on the sand, he pushed his neck backward until his head touched his back, a contortion necessary to inspect the heavens. He did not turn his head around like the ravens in the above photo but pulled it straight back. Of course, with no blue visible, I thought he was checking the fog for any passing trouble. Grog returned to his normal posture with his head in place before a crow flew over. He didn't give it a passing glance.

When he threw back his head again with his beak pointed straight up, I thought perhaps there were insects in the moist air worth his catching even though I couldn't see them. Once again, Grog returned to himself and uttered notes soft as the mist. The third time he craned his neck skywards with his beak a bit open, it was as if to drink the moist air. I thought maybe he really was thirsty. Then when we moved on, he did stop at a rivulet for a drink. What was he doing with these contortions? Perhaps Grog was trying the view from below, from my perspective rather than from his usual heights. 

As Bernd Heinrich noted, raven vision is excellent. He followed a raven with his binoculars who had been near him as it raced off to harass an eagle about two miles away. All Heinrich had been able to see at first was a dot in the horizon. Like all birds, ravens have binocular and monocular vision, ie. they can focus both eyes like us but they can also use each eye separately. Marzluff and Angell in their comprehensive book, In the Company of Crows and Ravens, note how corvids can rest one eye while keeping the other vigilant. They discovered that the corvids on either end of a line roosting for the night can rest their inner eye while keeping the outer eye on guard.