A Note on the Nesting of the Bush-Tit
A Note on the Nesting of the Bush-tit
On May 22, 1935, when on a short trip to the Argus Mountains in Inyo County, California, a nest of the Lead-colored Bush-tit was found about dusk in a dense atriplex bush near the road in Mountain Springs Cafion. When I shook the bush preparatory to investigating the nest, a brood of young (estimated at 7 or 8) swarmed out and escaped to near-by brush. I did not further investigate at the time, but the following morning four young; just able to fly, left the nest as I approached. Thinking the nest to be now useless to the family I removed it with the object of investigating the “species content” of the feathers which entered into the nest’s construction.
Much to my surprise there were five perfectly fresh, unsoiled eggs, which without question represented a second laying for the season., The first of these must have been laid for some days prior to the time the first brood was ready to leave. Such “overlapping” of broods, with the young of one brood acting as temporary incubating agents ,for the eggs of the second, was entirely new to my experience. When, recently, I mentioned the circumstance to Mrs. Joseph Grinnell, she said she believed that similar occurrences might be the answer to the extremely short time intervals which had elapsed between the first and second broods of certain pairs of bush-tits observed by her in the San Francisco Bay region.
The systematic status of the Argus Mountain bush-tits cannot be stated definitely at this time, since no specimens were taken. However, the birds observed were unquestionably of the “leadcolored” type, and probably (see van Rossem, Auk, vol. 53, 1936, p. 85) belong to the subspecies Psaltriparus tininm cecaummrum.
A. J. Van Rossem
San Diego Society of Natural History, San Diego, California, April 3, 1936
