Survival estimates for the northern spotted owl

An analysis of capture-recapture data is tailored to the biological charact eristics of the female northern spotted owl (Strix occidentalis caurina) by conditioning female capture on capture of paired males. This procedure is relevant for animals such as the northern spotted owl where field studies i ndicate that capture of females generally is dependent on capture of their mates. Application of the method to data collected in Washington State sugg ests that survival rates for adult females have remained constant over the time span of our data, 1990-1997.