Geography Reference
In-Depth Information
squirrel also silenced nearby nests of a Steller's jay and a brown creeper. Both
Pacii c-slope l ycatcher nests I'd found were abandoned after a single egg was
punctured, perhaps by the teeth of a deer mouse or the beak of a parasitic
cowbird. But many nests had also l edged. Pacii c wren, chestnut-backed chick-
adee, American robin, and red-breasted nuthatch families were clamoring after
their parents for food. Time was running short if I was to i nd the bushtits
before they l edged.
It was the vibration that i nally caught my eye. The tip of an outstretched
i r branch seemed to droop a little more than I had remembered, and it was
quivering! As I trained my binoculars on it, a male bushtit popped out. There,
i nally, was the nest; a tightly woven, pendulous stocking of moss that blended
perfectly into the emerald tip of the bough. A few minutes later the golden-
eyed female came in with a huge caterpillar. My presence deterred her not in
the least. As she disappeared into the mossy orb, it burst to life, shaking the
old i r branch and bringing a smile to my tired face. Five days later, l edgling
bushtits spilled forth like corks from a case of champagne.
During twelve years of searching, my students and I managed to i nd only
forty-three bushtit nests. As enthralling as each discovery was, they answered
only a few of my questions. Bushtit parents were quite successful, l edging
young from nearly six out of every ten nests. They were especially successful
in established neighborhoods and least successful in forest reserves—just as
expected for a suburban adapter. It was dii cult, however, to know the extent
of a bushtit's success, because the eggs and chicks developed in secret, deep
within the gourdlike nests. Occasionally, we counted l edglings as they hud-
dled shoulder to shoulder on a branch. But this appearance was a rare sight.
To estimate the annual number of young produced by a nesting pair of birds
required a more cooperative subject. Few ornithologists would argue that if
