Time-to-detection occupancy methods: performance and utility for improving efficiency of surveys

Area of Science:

• Ecology
• Conservation Biology
• Wildlife Management

Background:

• Occupancy methods revolutionized species distribution studies by separating detection from ecological processes.
• Traditional repeated-measures occupancy designs require extensive data collection, including repeat visits or multiple observers, to account for imperfect detection.

Purpose of the Study:

• To compare the performance of time-to-detection methods against traditional repeated-measures designs for visual encounter surveys.
• To evaluate the suitability of time-to-detection methods for different species and survey conditions.
• To inform optimal survey design for ecological monitoring and conservation.

Main Methods:

• Collected time-to-detection data during repeated-measures occupancy surveys for four amphibian species.
• Compared time-to-detection methods to repeated-measures designs based on the location and precision of occurrence parameter estimates.
• Utilized time-to-detection survey results to optimize future survey designs.

Main Results:

• Time-to-detection methods were most effective for widespread species with high detection probabilities and rates.
• Performance was lower for cryptic species or when detection was influenced by survey conditions.
• Single surveys were most efficient in person-hours, but long durations may be needed for high detection probabilities.

Conclusions:

• Time-to-detection methods provide valuable data for optimizing survey efficiency and achieving conservation goals.
• Integrating time-to-detection data into existing repeated-measures surveys requires minimal field modifications but offers significant long-term time savings.