Nest
They may be composed of organic material such as twigs, grass, and leaves, or may be a simple depression in the ground, or a hole in a rock, tree, or building.
The simplest nest structures are adapted to hide eggs from predators, shield them from the sun or other environmental factors, or simply keep them from being scattered in ocean currents.
[1] Many nest builders provide parental care to their young, while others simply lay their eggs and leave.
[1] Nest building reinforces social behavior, allowing for larger populations in small spaces to the point of increasing the carrying capacity of an environment.
Among mammals, the naked mole-rat displays a caste structure similar to the social insects while building extensive burrows that house hundreds of individuals.
Similar structures exist in the United States, created by pocket gophers, and Argentina, rodents of the genus Ctenomys.
Nests constructed by megapode birds have been mistaken for anthropological features by professionals, due to their exceptional height (10 metres [33 ft]) and abundance (hundreds in a single location).
[2] With the exception of a few tunneling mammals, nest builders exhibit no specialized anatomy, instead making use of body parts primarily used for other purposes.
[1] Nests help regulate temperature and reduce predation risks, thus increasing the chance that offspring live to adulthood.
[2] Bird nests vary from simple depressions in the ground known as scrapes to largely unstructured collections of branches to elaborately woven pendants or spheres.
[3] The rufous hornero nest is composed entirely of mud and feces, which is placed on tree branches to allow the sun to harden it into a usable structure.
[1] Typical bird nests range from 2 centimetres (0.79 in) in size (hummingbirds) to 2 metres (6.6 ft) (eagles) in diameter.
[4] Many mammals, including raccoons and skunks, seek natural cavities in the ground or in trees to build their nests.
For example, the female Fletcher frog beats secreted mucus into a froth, creating a structure that serves as a line of defense against thermal extremes, predation, and desiccation.
The female digs a hole in the center to lay her eggs, covers them, and then guards them for two months until they hatch.
When eggs start to hatch, she breaks open the nest which has hardened over time and leads the young to the water where she continues to care for them for another year.
[3] Sea turtles dig a hole in the sand above the high tide line in which they lay their eggs.
Paleontologists have identified a number of features that allow them to distinguish a nesting site from a random clustering of eggs.
One specimen was found fossilized atop a nest in a brooding posture, proving the animal had been poorly named (Oviraptor means "egg taker").
[1] A site known as Egg Mountain in Montana provides exceptional evidence of dinosaur nesting behavior.
Features often include ventilation systems and separate chambers for the queen, her eggs, and developing individuals.
[3] Bees and hornets often seek out natural cavities in which to construct their nests, also known as hives, in which they store food and raise their young.
[7] In the species Megachile rotundata, for example, females construct tubular-shaped nests in rotting wood as well as small holes in the ground, creating, each cell made from circular disks cut from plant leaves using the bee's mandibles.
[9] Bee nests are founded upon the wax the secrete from their bodies, while those of wasps are dependent on their ability to turn plant water into paper using their saliva.
[7] Vespid wasps build complex nests from paper-like material where they lay eggs in individual cells.
[4] The largest nests, built by members of genus Amitermes, stand nearly 7 metres (23 ft) tall with a similar circumference at the base, and host millions of individuals.
The mounds protect against drying and predation allowing many species to lose ancestral traits such as hard bodies, skin pigmentation, and good eyesight.
Magnetic termites construct their nests with flattened sides along the north–south axis to ensure maximum warming during the winter, while exposing minimal surface area to the harshest mid-day sunshine.
Because these materials are often useful for humans in construction, X. virgininica's nesting behavior presents the disadvantage of weakening wood in manmade structures.
Birds such as the honey buzzard specialize on wasp and bee nests, a resource also targeted by the tropical hornet.
