TY - JOUR T1 - Time budgets of confined nothern cardinals and Harris' sparrows in flocks and differences in observer data JF - Journal of Field Ornithology Y1 - 1992 A1 - Shuman, T.W. A1 - Robel, R.J. A1 - Kemp, K.E. A1 - Zimmerman, J.L. VL - 63 ER -