Integrated distribution modeling resolves asynchrony between bat population impacts and occupancy trends through...

Area of Science:

• Ecology
• Conservation Biology
• Wildlife Management

Background:

• Monitoring cryptic species with seasonal life cycles presents significant challenges.
• Traditional methods often involve collecting data from multiple field techniques, analyzed as separate lines of evidence.
• Integrating diverse data sources can improve accuracy and scope but faces hurdles with misaligned resolutions and observational uncertainties.

Purpose of the Study:

• To develop and apply a multi-scale, integrated species distribution model (MS-iSDM) for North American bats.
• To combine data from various monitoring types and seasons for a more comprehensive population assessment.
• To analyze 11 years of data for the imperiled tricolored bat (Perimyotis subflavus) to understand population trends.

Main Methods:

• Developed a multi-scale, integrated species distribution model (MS-iSDM) utilizing joint likelihood methods.
• Incorporated observational models accounting for false-negatives and false-positives.
• Integrated seasonal migratory connectivity and multi-scale ecological predictors.

Main Results:

• The MS-iSDM revealed clear patterns of population decline for the tricolored bat.
• Abundance declined by 74.8% (95% CRI: -79.7% to -69.3%), strongly correlating with white-nose syndrome impacts.
• Occupancy declined by 35.5% (95% CRI: -41.1% to -30.2%), particularly at the range periphery.

Conclusions:

• The integrated model provided consensus estimates, enhancing precision and spatiotemporal scope compared to analyzing multiple lines of evidence separately.
• Asynchronous trends between occupancy and abundance declines were explained by spatiotemporal variations in abundance.
• The study strengthens evidence of significant population declines in the tricolored bat, highlighting the utility of integrated modeling approaches.