wards sitting there for some time until the presumably rightful owner presently darted at the intruder and drove her away. The nest was composed largely of small achenes bearing soft pappus. Other items noted were fibers, minute leaves, feathers and a short piece of string, the whole bound securely to the branch with cobwebs.
One egg was found in this nest on the afternoon of June 6 and another the next morning, this before the wall of the nest were entirely filled in. The nest was by no means considered complete with the laying of the eggs, but additional material was constantly brought, so that at times the eggs were almost concealed by it. After 14 or 15 days' incubation the bird disappeared from the nest and was seen no more, at least in that vicinity.
The behavior of the hummingbird on the nest is directly opposite to that of many other birds. It does not remain motionless in the hope of escaping notice,
Fig. 47. Young Costa Humminbirds in nest (no. 1). Azusa, May 18, 1921.
but often flies when approached within 30 or 40 feet. If one stands quietly even at a much less distance it will soon return, to leave again at any sudden motion. Thus the idea of concealment of the location of its nest does not enter into its thoughts or instincts. Those nests which I have found have been so situated that a clear outlook could be obtained in at least two directions. The hummingbird while incubating seems to require but little time for procuring food, as I have seldom found them absent from their eggs, and of course the female is not relieved by her mate, as is the case with so many birds, nor is she fed by him as are the female finches. The owner of the nest shown in figure 49 was more shy than usual and it was necessary in securing the photograph to remain at some distance, operating the shutter with a thread while reflecting light on the sub-
