Travelling in the north west of South Africa, in the beautiful Kalahari desert, you may be surprised to come across what looks like a bale of hay suspended on a power pole! Further investigation will reveal a constant stream of feathered creatures entering and leaving the construction from below.
These are the nests of the Social Weaver Bird. Colonies of many pairs of birds gather together and each pair has its own particular nest within the structure.
Before humans kindly provided all those hundreds of power poles, the birds relied on Quiver Trees to provide a perch on which to set up their safe haven. The only thing they are not safe from at this height above the ground (in a tree) is snakes – but I am not sure if the snakes are still a problem if the colony is on a power pole.