Defining null expectations for animal site fidelity.

Area of Science:

• Ecology
• Animal Behavior
• Movement Ecology

Background:

• Site fidelity, the tendency for animals to return to previously visited locations, is a widespread phenomenon observed across diverse taxa.
• Current definitions often group various underlying mechanisms (memory, habitat selection, chance) under the umbrella term 'site fidelity', frequently assuming memory as the primary driver.

Discussion:

• This research proposes a novel operational definition for site fidelity, defining it as return patterns that significantly deviate from a null expectation generated by a memory-free movement model.
• Agent-based simulations demonstrate that intrinsic movement characteristics and extrinsic landscape features are critical determinants of return patterns, even in the absence of memory.
• The study highlights that random movements alone can result in substantial probabilities of return, challenging assumptions that all returns imply cognitive processes like memory.

Key Insights:

• Introduces a new, testable definition of site fidelity based on deviations from a memory-free null model.
• Empirically demonstrates the significant roles of inherent movement traits and landscape characteristics in shaping return behaviors.
• Provides a robust framework for distinguishing true site fidelity from patterns arising from random movement or environmental influences.

Outlook:

• This framework offers a standardized approach for empirically testing hypotheses related to site fidelity across various ecological systems and spatial scales.
• Facilitates more precise investigations into the ecological and evolutionary drivers of animal movement and habitat use.
• Enables researchers to better understand the cognitive and environmental factors influencing an animal's decision to return to specific locations.