Cumulative-link mixed effect ordinal regression (a) testing the effect of environmental, urban and human variables on the ordinal intensity of offspring defense; and (b) linear mixed effect model testing the effect of intensity of offspring defense in incubation on eventual fledgling production.

Cumulative-link mixed effect ordinal regression (a) testing the effect of environmental, urban and human variables on the ordinal intensity of offspring defense; and (b) linear mixed effect model testing the effect of intensity of offspring defense in incubation on eventual fledgling production.累积链接混合效应有序回归：（a）检验环境、城市及人为变量对子代防御行为有序强度的影响；（b）线性混合效应模型，用于检验孵化期子代防御行为强度对最终出巢幼鸟繁殖产量的影响。