Hamerkop (Scopus umbretta)
This African bird's nest is a massive, roofed structure set up in the fork of a tree near water. It takes about 8 weeks and 10,000 twigs to build, and is lined with mud for insulation and water-proofing. This takes a lot of effort, from both the male and the female. What's more, one nest evidently isn't enough. Hamerkop pairs build up to 4 nests a year, working all year round.
Ruby-throated Hummingbird (Archilochus colubris)
These hummingbirds build a tiny, knot-like structure attached to a tree branch with spider silk. The nest structure is crafted from bark, leaf strands and silk fibres, which make it strong and stretchable. It is decorated on the outside with lichen for camouflage and lined on the inside with hair or feathers for insulation.
Bald Eagle (Haliaeetus leucocephalus)
The eyrie of a bald eagle is a huge pile of twigs and sticks lined with leaves in the middle. A bigger size means the nest, which has a shallow centre, is safer. Assembling it on a high platform, like a large tree or cliff, ensures the parents can see danger from far away.
Edible-nest Swiftlet (Aerodramus fuciphagus)
This nest is made exclusively out of the bird's saliva. It is built in layers, usually over protruding rocks on inclined walls of a dark sea cave. Swiftlets nest in colonies of thousands. Their nests are harvested to make a Chinese delicacy: bird's nest soup.
Sociable Weaver (Philetairus socius)
As their name suggests, these birds nest and brood in groups. They build a gigantic nest-within-a-nest structure attached to trees and poles. A compound nest can house over 100 breeding pairs, each contributing to its construction, maintenance and repair. Living in groups means someone is always on the lookout for danger.
European Bee Eater (Merops apiaster)
This bird digs a horizontal cavity into the sand on a river embankment. To build a nest, a bee eater hovers over a suitable site, drills a hole with its bill, alights and then excavates a burrow using its feet to scoop out sand. The bird chooses the nest site with the utmost care, as the soil has to be soft, yet safe from caving in.
Baya Weaver (Ploceus philippinus)
Male baya weavers build an interwoven structure, suspended from a tree overlooking water. The male skilfully weaves grass strips to form a nest, which he shows off to females with a flutter of his wings. If a female approves of the nest, she will mate with him. The male then makes a few finishing touches to their home.
Horned Coot (Fulica cornuta)
Pairs of these birds build their nests in shallow waters, using pebbles carried from the shore in their beaks. The result is an island of pebbles weighing about 1.5 tonnes, topped with vegetation. The mound keeps the nest safe from water currents.
Gyrfalcon (Falco rusticolus)
Rather than building a nest, a gyrfalcon will take over an abandoned raven nest, or scrape a depression on a cliff ledge overarched by rocks. The nests are re-used year after year, by generations of gyrfalcons. One old nesting site in Greenland was found to have been in use for 2,500 years.
Little Grebe (Tachybaptus ruficollis)
This nest is a floating platform made from twigs and submerged aquatic vegetation. It is anchored to the bottom of a water body. The grebe builds it in shallow waters, with high surrounding vegetation for camouflage. The eggs are covered with wet or dry plant material, to hide them from predators and maintain temperature and humidity.
Common Tailorbird (Orthotomus sutorius)
This nest is the end-product of ingenious needlework by the bird. Armed with its beak and a silk thread, the tailorbird pierces the edges of a large leaf and stitches them together. It builds its nest in the frame of the arched leaf. The nests are well-camouflaged as they are built among thick foliage.
African Jacana (Actophilornis africanus)
Doubling up as a mating platform, the Jacana's nest is a fragile, floating pile of vegetation. The bird makes several, and chooses one for laying eggs. The nest is loosely anchored and glides precariously over water. Sometimes it sinks while the bird is incubating its eggs.
Red-cockaded Woodpecker (Leuconotopicus borealis or Picoides borealis)
Famously, woodpeckers nest in cavities drilled into living pine trees. It takes years for a breeding pair to excavate one. Sap oozing from the tree keeps away predators such as rat snakes.
Malleefowl (Leipoa ocellata)
The malleefowl's nest is a heap of decaying leaves, covered in a layer of sand. The heat from this compost incubates the eggs. The bird controls the temperature by adding or removing soil.
Great Hornbill (Buceros bicornis)
Hornbills nest in natural tree cavities, or abandoned woodpecker holes. Before laying eggs a female seals herself inside the nest behind a wall of mud and faeces. This keeps predators out. The male feeds her and the chicks through a narrow slit in the wall.
Purple moorhen (Porphyrio porphyrio)
In New Zealand, this species is popularly known as the pūkeko. Its nest is a bowl-shaped structure built on a platform woven out of trampled reeds and dead plants. It is lined with softer materials like ferns and grass. Each bird makes several nests, then lays its eggs in the most inconspicuous one. The eggs are sheltered with vegetation to keep away predators.