Not all bird nests are created equal. These are some of the most unusual bird nests from around the world, showcased for your viewing pleasure.
1. Cactus Ferruginous Pygmy-Owl

Photo: wildsonora.com

Photo: wildsonora.com
Found in the desert habitat of southern Arizona in the southwestern United States and northwestern Mexico at elevations below 4,000 feet (1,200 m), the Cactus Ferruginous Pymy Owl has a very long name for such a small bird. It can fit in the palm of your hand! Because of its tiny size, it can take advantage of its desert landscape and use cacti as its nesting place. Typically the holes are pre-made by woodpeckers looking for food, so the owl doesn’t even have to get its beak dirty! They’ve been known to roost in ironwood, mesquite, acacia, saguaro and organ pipe cacti. Unfortunately, this species is in grave danger from a loss of habitat.

Photo: owling.com
2. Sociable Weavers

Photo: adlayasanimals.wordpress.com

Photo: Vanessa Vermaak via Project Noah
Sociable weavers are found in the Kalahari Desert region in South Africa, Botswana, and Namibia. They are one of the best known of the “unusual nest builders” because of their huge, elaborate group nesting sites they create. In fact, they hold the record for the largest tree nests in the world. Instead of the birds building individual nests, they build one gigantic one for the entire colony. Over 100 sociable weavers can occupy a single nest at a given time and some nests have even remained occupied for over 100 years! You can compare the sociable weavers’ nest to that of a bee hive as there are tiny entrances into each “cell” or nesting space for individual birds. These nesting chambers are typically 4 to 6 inches (10 to 15 centimeters) in diameter and there can be as many as 5 to 100 nesting chambers in a single sociable weaver nest. These cells come in handy when the birds are trying to stay comfortable in the harsh climate of the Kalahari Desert. During the freezing winter nights, birds pack into the center chambers which are more insulated and thus keep them warmer. During the hot summer days, the outer chambers are most frequently occupied as they are a bit cooler. Some sociable weaver nests can be so heavy that they can weigh several tons. Many have even caused the trees they were in to fall down!

Photo: TyneWear-Rob
3. Edible-nest Swiftlets

Photo: http://anetindia.org/

Photo: Lim Chan Koon

Photo: http://grandviettour.com/
The edible-nest swiftlet is a bizarre bird native to South-east Asia. They craft their nests out of solidified saliva! The nests are typically white, opaque, and about 6 cm across built on rock caves near the shore. Much like bats, edible-nest swiftlets use a simple form of echolocation to navigate their dark cave habitats in order to build these strange nests and find food. Oddly enough, these nests are considered a Chinese delicacy and are collected to be transformed into “bird nest soup.” There has been significant worry about over-harvesting and so recently bird nest merchants are starting to raise and breed swiftlets in their own house-like structures where they can selectively choose for the best birds nests. Because the risk is much lower with “house nests” vs. “cave nests” they are substantially less expensive.

Photo: http://www.geeewizzz.com.au/
4. Maleo

photo: wallacefund.info

Photo: Kevin Schafer

Photo: Sandesh Kadur

Photo: http://news.mongabay.com/
The Maleo is a little-known bird that is only found on one place in the entire world – Sulawesi Island. That’s because of the incredibly unique way that it incubates its young. Instead of building a nest, per say, it buries its eggs in the sand. Sulawesi’s volcanic ground is heated by geothermal energy and so all the heat necessary for keeping the eggs incubated comes from the soil, not the bird. Even more interesting, the young have to dig out of the sand once they hatch much like turtles do… and they have the ability to fly as soon as they hatch! There are only around 10,000 of these remarkable birds left in the world and more conservation is needed to preserve the remaining population. The decline in numbers is due to the local people’s taste for Maleo eggs, among other things. The eggs are around five times the size of a domestic chicken egg and are packed with protein so they are a favorite supplement to the Sulawesi peoples’ diets.

photo: http://perierga.gr/
https://www.youtube.com/watch?v=KhbO1ywadqY
5. Bushtit

Photo: http://crazym.ca/

Photo: Valerie Easton

Photo: Brian Rockwell
Bushtits build unusual hanging sack-like nests, comprised largely of spiderwebs and moss, that may dangle as much as a foot from their anchor point. These small birds are found throughout western North America and work on building their nests for quite some time; the process could go on for a month or even more! To achieve the drooping effect, adults will sometimes sit inside during construction, dragging the nest downwards with the weight of their bodies. Insulating material such as feathers, fur, and plant matter and then work to camouflage the outside of the nest with bits of plants. Before beginning to build their nests, males and female pairs test out a variety of different spaces by hanging spiderweb from mistletoe or other vegetation.
6. Baya Weaver

Photo: zahoor_salmi
Sometimes touted as the “king of nest-building birds,” the Baya weaver uses his impressive nest-building skills to not only create a home but to attract a mate. During mating season, females go around and inspect each male’s nest, deciding which they find most pleasing. Studies have shown that nest location rather than nest construction has been more of an influence factor in female choosing. The nests are sock-shaped with a central nesting chamber and a vertical tube that leads to another entrance within the chamber. Nests are crafted by weaving long strips of paddy leaves, rough grassess, and palm fronds. It can take as many as 500 trips back and forth for the male to collect all of the materials necessary for building the nest. Once he has the items needed, he works tirelessly to weave the grasses together, forming the intricate structure. Baya weaver birds are found across the Indian Subcontinent and Southeast Asia, traveling in flocks which fly in close formations and can perform impressive maneuvers.
7. Black Swift

Photo: Ryan O’Donnell

Photo: Benjamin M. Clock
Touted as one of America’s most mysterious birds, the black swift chooses to create its nests behind waterfalls. Because of this species’ love of forbidding nesting sites, there has been little in the way of data collected on them. However, it was recently learned that the birds are wintering in remote river canyons of western Brazil some 4,000 miles away from their regular Colorado nesting sites. Scientists had always suspected that the birds wintered in North America but until now had no idea where. Thanks to the recovery of some geolocators, this particular mystery has been solved.
8. Bowerbird

Photo: viralforest.com

Photo: timlaman.com

Photo: http://incisive.nu/
Bowerbirds are known for creating elaborate and fantastical nesting sites in order to attract potential mates. Not only is the structure itself impressive, but typically the bower is decorated with other beautiful accessories (like flowers, iridescent beetle shells, or berries) to catch the female’s eye. The Satin Bowerbird, for example, favors blue trinkets. The older a bird is, the more blue objects he decorates his bower with. Blue berries, blue ballpoint pens, blue flowers, and blue discarded pieces of plastic have all turned up at the entrance to the Satin Bowerbird’s bower. A lot of hard work goes into building these bowers but unfortunately, it may be mostly in vain: a recent study showed that 75 percent of female birds visited only one bower before mating. There are 20 species of bowerbird which make up eight genera each with a different take on the “perfect nest.” Some other remarkable bowerbirds include the Great Bowerbird, which makes a twin-walled, avenue-like bower typically laden with white and green objects, and the Vogelkop bowerbird which decorates its bower with an impressive collection of festive-colored accoutrements.

Photo: Imgur
9. Southern Screamer

Photo: faunaparaguay.com

Photo: Jar0d
The Southern Screamer gets its name from its loud, easily recognizable call which can be heard up to several miles away. They are found southeastern Peru, northern Bolivia, Paraguay, southern Brazil, Uruguay and northern Argentina in wetlands such as flooded fields, meadows, marshes, lakes and lagoons. This bird chooses to build a huge nest on the ground out of reeds, weeds, sticks and other items close to the nesting site which is close to water and yet hard to access (unless you’re a Southern screamer). Since the large nests are made out of the same vegetation that stands nearby, the nests are almost impossible to find. Both the male and female, which typically pair for life, work together to build the nest.
10. Sand Martin

Photo: Ross Gardner

Photo: Neil Triggs

Photo: John Robinson
Sand martins are unusual, sociable little birds that nest in colonies numbering anywhere from 10 to nearly 2,000 pairs. They nest in burrows which are typically crowded together in a natural or artificial bank. The soil must be loose so that the burrows can be excavated. The burrows are perpendicular to the ground and when completed are dug about 25 inches into the side of the bank. The burrows are also established next to a large, open body of water so that the sand martins have plenty of access to this necessity as the majority of their diet consists of insects which spawn and/or congregate near the water. At the end of the excavated burrow, a nesting chamber is crafted from a mat of grass, rootlets, leaves, twigs, straw and feathers. It is there that somewhere between 2 to 7 white eggs are laid and incubated, mainly by the female. The breeding season of the sand martin runs between April and August.