Here are 3 of the coolest things built by birds:
1. Sociable Weaver Nests
Sociable Weavers are most commonly found in the Kalahari desert of southern Africa. These birds build huge nesting complexes that can host up to 400 hundred birds. They slightly resemble what it would look like if you took a haystack and stuck it on top of a tree but it’s the way they function that makes them so special. With the largest nests measuring up to 6 meters wide weavers use green grass to keep eggs falling out. They also use sticks and twigs to create a roof.
Sociable weaver nests retain heat very well so well that when the external temperature drops by up to 17 degrees Celsius, the inside of the nest will only usually lose about 1 degree of heat. The oldest of these complexes has been occupied for over 100 years and this could be due to the mechanisms in place to stop predators. Sharp straw spikes are strategically placed throughout the tunnels to deter predators like snakes and it would give them a pretty rough time if they tried to get in.
2. The Montezuma Oropendola’s Nests
These birds have designed incredibly innovative ways of keeping their eggs safe. They, like the sociable weaver have found strength in numbers and grouped of colonies of 20 or more can be found in a single tree. Females use vines and other fibers to weave the nests over about 2 weeks, they can end up being 60-180cm long and are suspended form a flimsy branch tip.
They build these nests in trees out in the open so monkeys wont predate the eggs, and they also have been known to build nests near hornet and wasp nests. Being so close to stinging insects deters predators and parasites
3. The Bowerbird ‘bowers’
these are not exactly nests but every male bowerbird will construct a ‘bower’ in his lifetime to attract mates. They do this by gathering twigs, leaves and moss to build a sort of cave-like structure and then spend as much time as it takes decorating with anything and everything they can find.
The more colourful, impressive and attention grabbing the ‘bower’, the better it is. There is a lot of heavy competition in this between males,so much so if a male bowerbird finds a bower not built by him, he will usually either destroy the nest or take from the valuables inside and add them to his own (he will usually destroy the rival nest anyway, just in case). Researchers have noticed the use of optical illusions to attract females also, with larger objects placed strategically in comparison to smaller ones to make the overall result look much brighter and bigger than it actually is.