|Painting by Steve Kirk.|
I am skeptical of this -"lounging," as is depicted here, is something that I've found in my studies (admittedly limited in comparison to some of my readers) to be a distinctly mammalian trait. Crocodiles, birds, and squamates do not, in my experience, exhibit this kind of resting behavior where they lay upon their sides, with the majority of their weight upon their ribcage, hip, and tucked-under leg.
Birds have a variety of sleeping postures and habits ranging from snoozing standing up (sometimes on one leg!), to nesting with both legs folded up under the body, to perching - or, in the case of some hummingbird species, hanging upside-down like little, feathery bats. Their heads are either tucked behind the wing, or pulled into their bodies with their beaks resting on their chests.
|...or like this.|
(Photo by Rinaldo Santos de Almeida)
|Photo removed at the request of the image distributor.|