Humans and giraffes, like most mammals, have 7 neck (cervical) vertebrae. The long-necked Apatosaurus (Brontosaurus of old) had 15. Flamingos beat all of them with 19 cervical vertebrae. So a flamingo has no trouble preening with its beak. I watched this Greater flamingo (Phoenicopterus roseus) as it woke from a nap and stretched its neck to work on its feathers.
Birds have a larger number of cervical vertebrae than mammals, ranging from 11 to 25. So flamingos are not special. I don’t know where on this scale the neck of the Great thick-knee (Esacus recurvirostris, aka Great stone curlew) should be placed. Whatever the number, this odd looking bird doesn’t have a neck flexible enough to groom its wing feathers. I watched as this one stretched out its leg to do that.
I find the name thick-knee extremely good for field identification, as you can see in the photo where the leg is stretched out to preen the wings. The knobby knees are clearly visible. These knees can bend forward, unlike mammalian knees. I was quite struck by the fact that the bird woke from a snooze and began to stretch its legs and wings, which are modified arms. Of course that must feel good.
That flamingo did the same thing, but only with one leg. Its knees bend the same way as ours. Most birds sleep with one half of the brain at a time. You can see this easily in waders which roost out in the water by the fact that one leg is retracted while it stands on the other. The relaxed leg is connected to the sleeping hemisphere. I didn’t think of looking to see which leg this individual was stretching. I don’t think I will go back to Jamnagar soon, but there are flamingos in the waters around Mumbai in winter; I’ll keep a watch to figure this out.