Depletion models can predict shorebird distribution at different spatial scales

Area of Science:

• Ecology
• Wildlife population dynamics
• Conservation biology

Background:

• Predicting habitat change impacts requires understanding carrying capacity.
• Depletion models estimate animal numbers based on prey density and predator foraging parameters.
• Existing models are limited to small spatial scales, hindering large-scale environmental change predictions.

Purpose of the Study:

• To assess the efficacy of depletion models in predicting population abundance at multiple spatial scales.
• To evaluate the application of depletion models for black-tailed godwits (Limosa limosa islandica).

Main Methods:

• Calculated predator handling time and searching efficiency from the functional response of black-tailed godwits to prey.
• Integrated prey density data from surveys with foraging parameters into a depletion model.
• Validated model predictions against Wetland Bird Survey data.

Main Results:

• Depletion models successfully predicted black-tailed godwit abundance at three scales: within mudflats, within estuaries, and between estuaries.
• Significant correlations were found between predicted and observed population densities.
• The models demonstrated predictive power across varying spatial resolutions.

Conclusions:

• Depletion models are effective tools for predicting site-specific population sizes across diverse spatial scales.
• These models enhance the reliability of environmental change impact assessments on wildlife.
• The study supports the broader application of depletion models in ecological forecasting and conservation planning.