Atmospheric Coherence as a Universal Trigger for Vertebrate Migration: Cross-Class Validation of the Phi_migration Framework Across Ten Species and Five Vertebrate Classes

PREPRINT — Submitted to Movement Ecology / Global Change Biology. We present the Phi_migration framework, which proposes a single universal departure trigger for long-distance animal migration: threshold crossings in the atmospheric electromagnetic coherence gradient (Phi_atmo >= 0.08 Phi/degree). This threshold, established empirically in migratory bird datasets, is validated across 10 species spanning all five vertebrate classes — Aves, Mammalia, Reptilia, Chondrichthyes, and Actinopterygii — without modification. Across 128 telemetry-derived departure events plus 515,764 eBird community checklists, all taxa respond to the identical Phi_atmo threshold with a mean advance latency of 3.6-3.8 days (z = 5.59-17.85, Cohen h = 0.838-2.809, all p < 0.0001). Three independent sensory pathways are characterized: magnetoreception (birds, cetaceans, salmon), barometric/infrasound sensitivity (elephants, caribou), and lateral line ocean-atmosphere pressure coupling (sharks, salmon). The universal 0.08 Phi/degree threshold — conserved across 450 million years of vertebrate evolution — suggests that atmospheric coherence gradients constitute a fundamental environmental signal to which the vertebrate nervous system has been tuned since the Devonian. Climate change implications include a novel mechanism for phenological mismatch: jet stream destabilization and Arctic amplification degrade Phi_atmo coherence boundary sharpness, potentially disrupting the signal that has organized vertebrate migration for half a billion years.