We saw Mrs. C. in the backyard today, and it looked as if she was starting to build a nest in the grapefruit tree!  I watched her take several twigs up to the same place in the tree.  She then went over to the flowerbed and started picking up other nesting material.  I got the camera and tried to photograph her nest-building activities, but she left.  After a while I went out and took some extra twigs and Squirt fur and scattered them near the tree.  I peeked in very quickly, and I think I saw the start of a nest.  Cool!