Using latent selection difference to model persistence in a declining population.

Area of Science:

• Ecology
• Conservation Biology
• Wildlife Management

Background:

• Population persistence is a key indicator of species viability.
• Declining populations necessitate understanding factors influencing their survival.
• Occupancy modeling provides a framework for assessing species persistence.

Purpose of the Study:

• To model western grebe (Aechmophorus occidentalis) persistence in Alberta.
• To identify environmental and anthropogenic factors affecting western grebe survival.
• To inform conservation strategies for declining western grebe populations.

Main Methods:

• Adapted occupancy modeling to estimate persistence probability.
• Utilized historical distribution data for western grebes.
• Assessed environmental covariates including emergent vegetation and human development.

Main Results:

• Persistence positively correlated with shoreline bulrush (Scirpus lacustris) extent, crucial for nesting cover.
• Western grebes were less likely to persist in boreal forest lakes, near the species' northern range limit.
• Persistence was higher on lakes with recreational development, indicating reliance on larger water bodies.

Conclusions:

• Shoreline vegetation and habitat type are critical for western grebe persistence.
• Recreational development, while correlating with persistence, poses a threat to brood-rearing habitats.
• Conservation efforts must address threats to nesting cover to ensure long-term population viability.