|copyright Chris Eason|
A first year weaver started building a nest in my garden recently - about 1,5m (5 feet) off the ground. He abandoned his construction - the nest was far too close to the ground to be safe from predators - but left this starting knot. If you look closely you'll see a loose series of half hitches and windings, twisting and braiding back over each other. Weavers do generally start their knots at a fork in a branch as well, to give the nest a better anchoring point.
Animal Architects (ebook) shows the sequence most weaverbirds follow to construct their nests: After the establishing knot, they tie a ring which they perch on while they build the roof, egg chamber and entrance, finally lining the nest in preparation for an egg to be laid.