Developing Gyrfalcon Surveys and Monitoring for Alaska.

A BSTRACT .—We developed methods to monitor the status of Gyrfalcons in Alaska. Results of sur veys and monitoring will be informative for resource managers and will be useful for studying potential changes in ecological communities of the high latitudes. We estimated that the proba bility of detecting a Gyrfalcon at an occupied nest site was between 64% and 87% depending on observer experience and aircraft type (fixed wing or helicopter). The probability of detection is an important factor for estimating occupancy of nesting areas, and occupancy can be used as a metric for monitoring species’ status. We conclude that surveys of nesting habitat to monitor occu pancy during the breeding season are practical because of the high probability of seeing a Gyr falcon from aircraft. Aerial surveys are effective for searching sample plots or index areas in the expanse of the Alaskan terrain. Furthermore, several species of cliff-nesting birds can be surveyed concurrently from aircraft. Occupancy estimation also can be applied using data from other field search methods (e.g., from boats) that have proven useful in Alaska. We believe a coordinated broad-scale, inter-agency, collaborative approach is necessary in Alaska. Monitoring can be facil itated by collating and archiving each set of results in a secure universal repository to allow for statewide meta-analysis. Received 16 September 2011, accepted 10 November 2011. F