Uncertain consequences of releasing game‐farm mallards: further insights and implications

Mallards ( Anas platyrhynchos ) have been domesticated and released in Europe and North America for centuries to supplement hunter harvest and in attempts to increase populations. They have interbred with wild mallards, most notably in the Atlantic Flyway of North America. Published research indicates that >90% of mallards harvested in the Atlantic Flyway are hybrids, and the species has formed a hybrid swarm of wild‐strain and game‐farm (GF) birds. An ongoing survey by Ducks Unlimited has revealed that GF ancestry in mallards is widespread in the United States, being detected in harvested birds in 48 of 49 sampled states. Studies further showed that GF mallards are sources of viral pathogens that could transmit to wild birds and poultry. There also is concern that release of GF mallards onto wetlands where other migratory waterfowl occur and are hunted is possibly creating live‐decoy effects. Given these uncertainties and possible negative consequences, scientists are encouraged to determine the principal drivers of cross‐seasonal and annual population vital rates of genetically vetted wild, feral GF, and hybrid mallards. An opinion survey of waterfowl hunters and conservationists in general is warranted to understand human perceptions regarding releasing GF mallards. I predict the hybrid swarm and associated problems with release of GF mallards will not end given continued annual releases of tens of thousands of GF mallards and their genotypic persistence, as reviewed herein. I hope published scientific evidence and this commentary incite continental‐scale research and resolution of this unnatural yet legal practice.