show Abstracthide AbstractWe investigated the stability of a well-studied hybrid zone in Bocas del Toro, Panama involving the golden-collared manakin (Manacus vitellinus) and the white-collared manakin (Manacus candei), two tropical bird species with lek breeding behavior. Given previously documented female preference for golden male collar color and the strength of sexual selection in this system, we hypothesized that male secondary sexual traits in this hybrid zone would move northwestward toward candei over time. We resampled the hybrid zone ~25 years after initial surveys to assess its temporal stability. A genomic hybrid index based on thousands of SNPs showed that the geographic location of the genomic transition between these species has remained stable.