Influence of including a covariate for detection and subsampling on bias of estimated trends, when stopover duration (indexed by daily survival probability <i>phi</i>_<i>i</i>) increased systematically over time.

<p>Reference categories for the independent variables in the linear regression model were an increase in <i>phi</i>_<i>i</i> between 0.40–0.50, no subset, and no covariate.</p><p>Influence of including a covariate for detection and subsampling on bias of estimated trends, when stopover duration (indexed by daily survival probability <i>phi</i>_<i>i</i>) increased systematically over time.