'You shall not pass!': quantifying barrier permeability and proximity avoidance by animals

Area of Science:

• Ecology
• Animal Behavior
• Conservation Biology

Background:

• Animal movement is crucial for ecological dynamics, but impediments like roads and fences fragment landscapes.
• Understanding how animals respond to movement barriers is essential for effective species and landscape management.
• Anthropogenic features pose significant, yet poorly understood, challenges to wildlife movement.

Purpose of the Study:

• To develop a mechanistic modeling framework for quantifying barrier permeability and proximity effects on animal movement and habitat preference.
• To provide a statistical method for estimating movement, habitat preference, and barrier permeability parameters.
• To apply this framework to assess the impact of roads on wild mountain reindeer summer movements.

Main Methods:

• Developed a mechanistic modeling framework to simultaneously quantify barrier permeability and proximity effects.
• Used simulations to demonstrate statistical estimation of movement, habitat preference, and barrier permeability parameters.
• Applied the model to a case study of road effects on wild mountain reindeer movements.

Main Results:

• The framework provided unbiased and precise parameter estimates for movement, habitat preference, and barrier permeability.
• Permeability estimates were influenced by barrier crossing frequency and proximity of locations.
• Reindeer exhibited avoidance of areas near roads, with roads acting as semi-permeable barriers, reducing movement probability by up to 68.6%.

Conclusions:

• The developed framework effectively quantifies animal responses to movement barriers.
• Roads significantly influence wildlife behavior, causing avoidance and reduced movement, highlighting infrastructure impacts.
• This approach addresses knowledge gaps regarding the consequences of human infrastructure on animal movement and ecology.