How interactions between animal movement and landscape processes modify local range dynamics and extinction risk.

Area of Science:

• Ecology
• Conservation Biology
• Computational Biology

Background:

• Species distribution models often use simplified distance-based dispersal, neglecting how individual behavior and landscape structure influence movement (functional connectivity).
• Understanding functional connectivity is crucial for accurate predictions of species range dynamics under global change.
• Wetland-dependent turtles in tropical savannahs face threats from invasive species and overexploitation, highlighting the need for precise range shift modeling.

Purpose of the Study:

• To integrate individual-based and niche-population models to explicitly simulate functional connectivity.
• To assess the impact of functional connectivity on range dynamics and extinction risk for a threatened turtle species.
• To identify biases in current range shift models and propose improvements.

Main Methods:

• Linked an individual-based model (IBM) with a niche-population model.
• Applied the coupled model to a turtle species in a patchy tropical savannah wetland system.
• Compared model projections with and without explicit functional connectivity.

Main Results:

• Explicitly modeling functional connectivity substantially changed projections of local range dynamics.
• Accounting for functional connectivity increased estimated extinction risk for the study species.
• Predictions indicated a slowing of range contraction when functional connectivity was considered.

Conclusions:

• Explicitly modeling functional connectivity is essential for reducing bias in species distribution and abundance predictions.
• Current range dynamics models may overestimate range shifts due to simplified dispersal assumptions.
• This approach offers a more realistic framework for conservation planning, especially for species with strong behavioral responses to landscape structure.