Fig. 1

Model Brown-headed Cowbird egg used in this experiment compared to real eggs. Illustrated from left to right are: two real cowbird eggs, one model cowbird egg, and three Red-winged Blackbird eggs
Model Brown-headed Cowbird egg used in this experiment compared to real eggs. Illustrated from left to right are: two real cowbird eggs, one model cowbird egg, and three Red-winged Blackbird eggs