Imagine yourself walking along this impressive avenue, with its high walls and many splendid treasures! For added strength, the builder has carefully interwoven numerous twigs into the walls. He has also painstakingly painted the walls with hoop pine and saliva, which he has personally mixed in his beak. Typical of all avenues built by this bird, the path runs in a north-south direction.
The collected treasures of this bower range in color, though there's one color that predominates. This bird loves blue, and it's not too difficult to imagine why.
Which of the following bowerbird couples belongs to this bower?
