Study Finds Game-Farm Ducks Alter Wild Mallard Genes
Research from a UTEP doctoral student traces how releases of domesticated ducks changed the genetic makeup of wild North American mallards.
Updated on Nov. 8, 2026 in Wildlife
A doctoral student at the University of Texas at El Paso led a study published in Current Biology documenting when and where domesticated duck releases altered the genetics of wild mallards. The research found captive game-farm mallards carry about 35% less genetic diversity than wild mallards.
Why it matters
Interbreeding with domestic stock can erode local adaptations in wild populations and increase the burden of harmful genetic variants. The findings also suggest game-farm birds with low diversity may have weaker immune defenses during avian influenza circulation.
The analysis drew on more than 400 historical museum specimens and over 600 contemporary mallards, with captive game-farm birds showing about 35% less genetic diversity than wild mallards. Whether these genetic differences translate into measurable health effects in the wild has not been established.
The players
University of Texas at El Paso
A public research university in El Paso, Texas, whose doctoral student led the mallard genetics study.
Current Biology
A peer-reviewed scientific journal published by Cell Press that released the study.
The details
Researchers reconstructed North American mallard genetic history from 1800 to 2020 across the continent's four major migratory flyways. Domestic ancestry entered wild populations in repeated waves that tracked regional stocking practices, with the first signs appearing in the 1910s and 1920s.
Timeline
1800 to 2020: Period of North American mallard genetic history reconstructed by the study.
1910s and 1920s: First signs of game-farm ancestry appear in wild ducks.
Seasonal Patterns
The study extends prior mallard genetic work by using historical museum specimens to date when domestic ancestry first entered wild populations. It shows that the stocking-driven shifts of the early twentieth century left a long-term genetic signature across North America's migratory flyways.
For El Paso residents who hunt or birdwatch, the findings highlight how stocked game birds can differ genetically from wild ducks. The study does not describe any changes to local hunting rules or wildlife management in the area.
The takeaway
Genetic records from museum specimens can reveal how human stocking practices reshaped wildlife decades later. Readers interested in wildlife conservation can use such historical data to understand long-term population changes.
Further reading
Explore more on the Wildlife section for context on how captive releases affect wild animal populations.
Source note: This article includes information reported by KTSM 9 News.
