Caribou movement as a correlated random walk.

Area of Science:

• Ecology
• Zoology
• Movement Ecology

Background:

• Animal movement is key to environmental interaction, but empirical analysis is limited.
• Caribou are the most mobile, non-flying terrestrial vertebrates, making them ideal for studying long-distance movements.

Purpose of the Study:

• To test theoretical knowledge of animal movement using correlated random walk (CRW) models and satellite telemetry.
• To investigate long-distance movements of both migratory and sedentary caribou.

Main Methods:

• Quantified individual caribou paths using mean move length and angle.
• Compared net squared displacements to CRW model predictions at different temporal scales.
• Analyzed temporal scales including annual cycles, seasonal behaviors, and short intervals post-calving.

Main Results:

• CRW models overpredicted caribou net displacement over an annual cycle.
• Excellent agreement between CRW predictions and observations occurred at shorter, seasonally defined intervals.
• CRW models overpredicted movement during specific periods (post-calving, late summer, late winter) due to tortuous paths, but underpredicted during spring migration, indicating straighter movements.

Conclusions:

• CRW models are applicable to vast spatial and temporal scales of animal movement.
• Findings assist in developing sophisticated models for population spread and redistribution.
• Understanding caribou movement patterns provides insights into migration and limiting factors.