Is ungulate migration culturally transmitted? Evidence of social learning from translocated animals

TLDR

Ungulate migrations are presumed to arise from learning and cultural transmission of seasonal forage information, yet this hypothesis had not been empirically tested. We compared the migratory tendencies of bighorn sheep and moose that were translocated into new habitats with those of long‑established populations that had persisted for centuries. Initially, translocated individuals did not migrate, but after several decades they learned to track forage phenology and increased their migratory behavior, showing that learning and cultural transmission are the primary drivers of ungulate migration and that loss of migration would erase critical knowledge and threaten population abundance.

Abstract

Ungulate migrations are assumed to stem from learning and cultural transmission of information regarding seasonal distribution of forage, but this hypothesis has not been tested empirically. We compared the migratory propensities of bighorn sheep and moose translocated into novel habitats with those of historical populations that had persisted for hundreds of years. Whereas individuals from historical populations were largely migratory, translocated individuals initially were not. After multiple decades, however, translocated populations gained knowledge about surfing green waves of forage (tracking plant phenology) and increased their propensity to migrate. Our findings indicate that learning and cultural transmission are the primary mechanisms by which ungulate migrations evolve. Loss of migration will therefore expunge generations of knowledge about the locations of high-quality forage and likely suppress population abundance.