ABSTRACT
A form of self-injurious activity resulting from defective employment of the sense of sight, is the fighting of a bird’s own image reflected in the glass of windows, on the supposition that the image is another bird. An important type of maladaptive activity among birds is that involving the impulse to run away from danger. The role of this impulse is of vital importance in nearly all birds and mammals. The maladaptiveness of the bird activity due to this impulse may be traced in certain cases to its underfunctioning, and in others to overfunctioning. One of the most striking instances of the complete absence or very poor development of this impulse among birds is presented by the Franklin Grouse of Oregon, Washington, and British Columbia. Under some circumstances, the birds’ activities were highly self-destructive in the state of nature.
