_Food._--Nothing definite seems to have been published on the food of Lucy's warbler, but it is evidently largely, if not wholly, insectivorous, as it is often seen foraging in the foliage and flower clusters of the mesquites and in other trees. Dr. W. P. Taylor tells me that he has seen it feeding on the pendant sprays of ocotillo flowers, probably gleaning insects or other materials from the exterior. In late spring when the mesquites, palo verdes, the various cacti, and even the saguaros burst into full bloom, these gorgeous desert plants are a blaze of color and attract myriads of insects. _Behavior._--Mr. Gilman (1909) says that "shyness about the nest seems to be characteristic of these birds." He was seldom able to flush one from its nest. "In three cases only, did the parent birds show what might be called proper amount of solicitude when the nest was approacht. Some of them seemed rather touchy about their nests, leaving them if the nest were toucht even so lightly." Some nests, with incomplete sets, were deserted after they had been inspected; but others were not. "They took good care not to sing in the nest tree, preferring to confine their performances to trees some distance away. The male would frequently meet me several rods from the nest and flit from tree to tree singing at short intervals. Once I made a complete circuit of the nest tree and he accompanied me the entire distance. This was an exceptional case of course. While going from tree to tree and singing, the bird usually tried to keep hidden as much as possible and was rather successful in the effort." However nest-shy the bird may be when there are eggs in the nest that she does not want discovered, the bird that I watched was not at all shy about her nest, nor was she lacking in parental devotion. For, although my camera stood within a few feet of the nest and I was standing beside it in plain sight, she came repeatedly to feed her young. I should say that these birds are more retiring than shy. W. L. Dawson (1923) writes: "Albeit an active creature and zealous in song, the Lucy Warbler becomes almost invisible in its habitual setting, and the difficulty of detection is heightened by the bird's instinctive wariness. Again and again I have known a bird which had seemed quite engrossed in song to fall silent at the stir of a footstep a hundred yards away."