Ydenberg, R.C. 1994. The behavioral ecology of provisioning in birds. Waite, T.A. and R.C. Ydenberg. Shift towards efficiency maximizing by gray jays hoarding in winter. Dots are measurements of individuals tested in summer, squares are measurements of the same individuals tested again in winter.
Open squares are individuals tested only in winter.
All individuals shift toward efficient behavior in winter. This page last updated February 2000.