The Avian Flight Neural Conduction Index (AFNCI): A Proposed Framework for Integrating Thermal Physiology into Flight Biomechanics

(Version 1.0.1: Replaced corrupted PDF file from original upload. Content remains unchanged.) Avian flight kinematic studies have historically focused on the mechanics of feather adjustment without fully accounting for a key physiological variable: the temperature of the peripheral nerves controlling the primary and secondary flight feathers. The capacity for precise, high-speed feather adjustment is intrinsically linked to the internal temperature of the nerve axons, which can be significantly cooled by airflow during flight. To address this, we introduce the novel and unique Avian Flight Neural Conduction Index (AFNCI), a conceptual framework that models neural function on a normalized scale from 1.0 (maximal nerve conduction) to 0 (functional paralysis). The AFNCI provides a quantitative tool to integrate thermal physiology with biomechanics, offering a new dimension for interpreting avian flight performance and recontextualizing past kinematic data.