In the city centre of Amsterdam, a seemingly ordinary bird nest tells an extraordinary story of human impact on the environment. It's constructed from unexpected materials, including sunglasses ...

Feathers — If you have old down feather pillows you don’t want ... would be a great source for nest building, it’s not. It’s too easy for a bird’s leg or wing to get tangled in the ...

Neighboring groups of birds within the same species can create very different-looking nests — showing that their nest-building choices aren't solely controlled by instinct and the environment.