Inferred maternal lineages and their associated paternal lineages that explain the genetic diversity of each brood as determined in the program COLONY are provided.

Maternal species identity was inferred from their respective ADMIXTURE assignment probability (Fig 3). Paternal species identity was inferred through comparing the maternal and offspring ADMIXTURE assignment probabilities as any differences are the result of different paternal and maternal lineages. The number of sampled eggs that are explained by the pairing across broods are provided in parenthesis next to the inferred paternal lineage. Paternal lineages found in more than one pairing are denoted with asterisk. Note species’ identities included American black duck (ABDU), wild mallard (WMA), and game-farm mallard (GFM) (also see S1 Table for sample specific information).