Not a lucky hunter with a hybrid to contribute?
Here’s another way to help!
When we started this project in the 2013/14 season, I worried that we would receive too few specimens to draw conclusions. But hunters have generously contributed over 25 whole hybrids and about 25 tissues from hybrids that were mounted. Additional fresh or dried wings have come from the annual USFWS harvest surveys. While still need many more specimens, progress is slowed now, not by a lack of specimens, but by funding for the genetic analyses.
Thus the luck of shooting a rare hybrids is no longer the only way you can help! We need at least $100,000 for genetic studies of the specimens. Both hunters who contribute specimens and others who support the genetic work with contributions of $500 or more will be acknowledged in the publications based on these specimens.
Two surprises greatly upped the ante for the genetic work. First, we assumed that most hybrids would be first generation crosses. But preliminary genetic results have uncovered many backcrosses. This is interesting and significant to conservation: Backcrossing generates horizontal gene flow between hybridizing species, which can greatly affect genetic diversity and the potential for rapid evolution in small populations. Of course too much backcrossing would erode species differences and result in extinctions of species through aggressive hybridization, but this is not an issue with most of the hybrids we are studying. [It is, however, an issue in other circumstances such as introduced Ruddy Ducks interbreeding with White-headed Ducks in Spain (you can read more about that here and here) and introduced Mallards interbreeding with Grey Ducks in New Zealand.] The second surprise was that some hybrid combinations show characters that are not expressed in either of the parental species. Many hybrids, like Mallard x Pintail or Gadwall x Green-wing Teal drakes are obvious blends of their parental species, but others, like Gadwall x Shoveler drakes (see the hybrid gallery) show color patterns not found in either parental, making plumage inferences about parentage uncertain.
Thus, odd hybrids and the high frequency of backcrosses, are demanding much more genetic work that we initially anticipated. Sometimes additional genetic work is needed just to be certain of the parentage of unusual hybrids.
Only F1 hybrids tell us initial siring asymmetries, so we must be certain that our tests of hybrid origins are based on F1 hybrids and not backcrosses. Identifying F1 hybrids requires much genetic work on pure parentals. Fortunately, that same work gives us information on the direction of gene flow between species. If backcrosses occur with both parental species, then gene exchange could be mutual. However, under strong (or complete) siring asymmetries, sexual imprinting suggests backcrosses will be with the maternal species, resulting in asymmetrical gene flow from the paternal species into the maternal species.
Exciting discoveries should come from this genetic work, but it seriously ups the ante for the project! I’m not a gambler, and I’ve never shot a hybrid in many years of duck hunting, so I like the silver lining: You no longer have to be a lucky hunter to contribute to this study: we need help with the genetics as well. The University of Washington Foundation is a non-profit, so gifts are tax deductible. I’d love to hear from if you might like to support this work: rohwer@uw.edu.
Check out the other pages and remember we need many more hybrids too! Thanks for your interest!
Check out the other pages and remember we need many more hybrids too! Thanks for your interest!