Modeling Complex Seasonal Avian Migration: Predictions From the Thermal Environment and Resource Availability

Billions of birds undertake long-distance migration and the complexity schedules has only recently become clear. Such movements occur as a response to seasonality but ultimate drivers these changing distributions remain difficult study directly. Modeling seasonal based fundamentally on climate vegetation without parameterizing with empirical data, we focus potential role ambient temperature available resources in shaping migratory program. We simulate complete annual cycle over Afro-Palearctic region round-trip model allowing full variation extent timing movement, multiple stopovers. The resultant simulated tracks associated environmental metrics are interrogated: evaluate thermal resource consequences staying Europe versus crossing Sahara, secondly identify movement patterns optimizing exposure green local surpluses. There is distinct gain from Sahara pattern emerging optimal resembles contemporary routes regarding crossing, loop structure itinerancy. Thus, our first-principle simulations suggest that variations among species caused by complex trade-off between risks rewards moving, including innate physiological constraints high-risk crossing.