Does the Russet Backed Thrush Have Defective Eyesight?
Journal
Condor
Volume
47
Issue
5 (September-October)
Year
1945
Pages
216
Section
From Field and Study
Online Text
Does the Russet-backed Thrush Have Defective Eyesight?-When, during migration seasons, reports have been received of birds killing or maiming themselves by flying against glass windows or doors, at least 90 per cent of the victims identified by me have proved to be Russetbacked Thrushes (HyZocichEa ustulata ustubta). As this species is by no means our most common migrant in southern California, some physiological deficiency appears to be indicated. The most natural assumption would be that the eyesight of the bird functions inefficiently, but that, of course, cannot be proved without further study.-G. WILLETT, Los Angeles County Museum, Los Angeles, California, June 16,1945.
