Nesting and Roosting, dinosaurs at rest
When one sees today's existing dinosaurs, the birds, at rest, one will most often see them roosting high in a tree, either perched upon a branch, or in a nest. The non-avian dinosaurs of spec, creatures that, in the distant past, gave rise to the birds show us that dinosaur roosting patterns are as diverse, if not more diverse, than those of "conventional" birds.
The very largest dinosaurs, sauropods, have never worried about finding secluded places to sleep. At such a huge size, they simply sleep where they stand, not even lying down.
Nesting of all large, naked skinned dinosaurs, which live in warmer climates, consists of scraping a crater-like depression in the ground, then covering it in a mound of vegetation. This matter composts and, with monitoring and care from the parent, warms the eggs, incubating them until the young hatch. Hadrosaurs and sauropods mostly allow the young to fend for themselves in small groups after they hatch. Herd life is usually to dangerous and fast paced for dinosaur chicks, and nest-young will join a herd after they mature to at leat half of adult size.
Theropds, on the other hand, care for their young like birds. Some, like large tyrannosaurs, will carry the hatchlings in their mouth to protect them, possibly a trait that may be common to some prehistoric archosaurs, just as crocodiles carry their young from land to water after hatching. This is merely speculation at this point, and may simply be a way for larger archosaurs to ensure their young's protection.
Large theropods usually have a cleared area, or bowl, secluded in cover, where their young remain protected, and the adults sleep and socialise at night. These nests, sometimes lined with underfeathers or vegetation, sometimes simply a scrape in the ground, are mostly temporary in the more nomadic hunters, but species with territories, like some dromeosaurs and most tyrannosaurs, may have a bowl for several generations. One from a mated pair or group will usually "chicksit" whiler others hunt and survey the territory, such behavior is typical of other warm-blooded beasts like mammals and avians.
Therizinosaurs sleep standing in a huddle for protection, with their heads tucked under their arm-feathers. Draks usually sit on their enlarged hip-bones, similarily with the head tucked under like a bird. Cedunasaurs, and some species of oviraptorosaurs, which have more flexible tails than dromeosaurs, are able to lay their tails around them when they sleep, enabling them to further insulate themselves and decrease the amount of heat lost.
Brooding over eggs like a bird is the domain of the theropods, the parent sits in a patch of bare soil in the centre of the nest, body warmth and elongated brooding feathers helping wram and protect the eggs and chicks. Most smaller maniraptorans sit in the centre of their nest, and spread their feathered arms and elongated brooding feathers over the eggs to keep them warm. Therizinosaurs develop particularily long and fluffuy brooding feathers around their torso, tail, and legs, covering the eggs, while the bulk of the animal sits in the centre. Tyrannosaurs, which have tiny arms, subsequenty develop a long, extensive "train" of brooding feathers growing from the belly, side, thighs, and tail, to cover the eggs while brooding.
Some varieties of draks, especially those which live in colder climates of the holarcic and nearctic, have developed a different brooding method. The parent will lay only two eggs, and brood them in special pouches, one under each arm. The skin lining the pouch has a constant and abundant blood supply, efficiently warming the eggs. This way, the parent can continue to feed, travel and hunt, with the eggs safely stored in her brooding pouches. The hatchlings are usally carried in these pouches after hatching for a short periopd of time, untill they become strong enough to follow their parents.
When sleeping, most theropods and birds tuck their head under their arm-or-wing feathers, keeping exposed areas warm. Small theropods, mainly ones under 3 metres long, are able to dig out areas in which to retire and nest. Mostly in secluded, inconspicuous areas, like tree-holes, logs, riverbanks, and under rock-outcroppings, these areas are the nucleus of the territory. These areas are well kept, lined with nesting material, and usually remain parasite free. Some of the most pleasant sights in all of spec are seeing mattiraptors or cedunasaurs emerge warily from their nest-holes as they awake to forage. The terminology of nest-holes varies depending on the species, hogbirds and glucks have "sets", mattiraptors have "earths", cedunasaurs have "dens", and smaller draks and even bruisers, quite suitably, have "lairs", alvies are usually referred to as having "lodges", after their habit of digging out termite mounds as roosting and nesting areas.
Small ornithopods, the usually two legged and herbivorous beasts found in many areas, generally have burrow-like structures in the smaller species. This subject is generally little-resarched, especially considering the remoteness and impenetrability of the habitats of beasts like viris and hypsies. An exception are dendrosaurs, which live and nest primarily in trees, making a bed of leaves in the fork of a large branch, like some HE primates and rodents. Such a structure becomes more permanent and insulated when eggs are layed and cared for. Living in suitably warm areas, all of spec's ornithopods bury their eggs in a compost-mound nest, keeping the nest at the right temperature untill the eggs hatch.
Arborial theropods like arbos and carpos most often make a bird-like nest to roost and nest in, made of any number of natural materials, generally varying greatly between species. Some arbos and arborial dromeosaurs will simply perch on a branch to sleep, anchored with clawed feet and hands. Ninjas in sumatra also do this, but they are easily disturbed, often with tragic results.
Seaguins are the only variety of spec bird which have a truly remarkable and unprecedented brooding method worth mentioning in this account. They typically make no formal nest and incuabte the single egg in a special "brooding chamber" inside the body, just before the cloacal opening. This allows them to remain in a cold area while they incubate their egg, the chamber's lining has an abundant blood supply to warm the egg and it's developing embryo. When the time comes for the egg to hatch, it is ejected from the chamber and cradled in the mother's large feet. After hatching, one parent will always remain with the chick, while the other gathers food, untill the chick is large and strong enough to fend for itself.
Most of spec's avians will roost and nest as they do in HE, either on a branch, in a nest, or on the ground in some species. But with many other dinosaurs existing in spec, we gain a fascinating insight into the little known habits of the more ancient archosaurs.