Tufted titmice have begun nest building. I'll find their complete clutches of five to nine eggs in a week or two. After laying one egg each day, the songbird mode, females cover the clutch with nest material, which may include snakeskin, moss, cedar bark, mammal hair, and paper, effectively hiding the eggs from view. Carolina chickadees do the same thing. As I throw out combed hair from our dog and cat, titmice and chickadees pick it up for nesting. When I open nest boxes to examine their contents, incubating females of both birds hiss like snakes, an excellent ruse to foil predators, except snakes. Titmice babies hatch in early April, fledge two weeks later, accompany their parents to my feeders, and feed themselves by late April, about the same time as fledgling Carolina chickadees. Conflicts are not apparent, because the families avoid one another. Scrappiness that so characterized chickadees during nest site selection has disappeared. I guess it's because the nesting effort is successful, so why spend unnecessary energy at an abundant food supply -- a matter of food's cost : benefit. The youngsters will stay home through the summer, apparently because a familiar area with food, family alarm system, and other learning opportunities outweigh early dispersal. western black-cresteds. Most adults have moderately dark crests with rusty foreheads. In the west, they sport longer black crests with tan foreheads, and to the east they have undistinguished gray crests with blackish foreheads. Our hybrid zone is around four miles wide along the north-south trending Balcones Escarpment and has been stable over the four decades that I've watched it. Black-crested and tufted titmice maintain their separate identities except in the ravine and vicinity -- this meeting place of eastern deciduous forest and western evergreen woodland.