OutdoorNebraska

4 R ecently, a bird mount was discovered at the Nebraska Game and Parks Commission that turned out to have some historical significance. The mount was of a purported Barnacle Goose, a Eurasian species that occasionally wanders to North America. This specific bird was harvested in 1968 in Otoe County by Milton Muncie. We know this because there was an article about this notable occurrence published in the Nebraska Bird Review in 1969. Mr. Muncie's Barnacle Goose was reported as a Nebraska first. However, records of Barnacle Geese in North America before the early 2000s were generally dismissed as representing escaped domestic birds because the species is also kept in captivity in North America. This conclusion has more recently been shown to be incorrect as wild Barnacle Geese that nest in Greenland do, on occasion, reach North America, primarily eastern Canada and northeastern U.S. So, is it safe to conclude the Nebraska specimen is a wild bird? Not necessarily, but possessing the carcass and, more specifically, its feathers provide the opportunity to find out. Stable isotope analysis is a method used to determine the origin of an animal because certain isotopes, such as the heavy hydrogen isotope, Deuterium, vary with weather conditions, resulting in predictable spatial variation in the signatures across continents. Feathers are composed of keratin, which does not break down after it is synthesized by an organism thus "fixing" the deuterium signature of an individual bird. Conducting stable isotope analysis on feather samples from a bird should tell us if it grew its feathers at a northerly or a temperate locality. A northerly signature would suggest a wild bird and a temperate signature would suggest an escaped captive bird. We used Wildlife Conservation Fund dollars totaling about $100 to have stable isotope analysis conducted on this bird's feathers. Long story short, the results showed that this bird grew its feathers at the northern location in northern Canada or Greenland, thus suggesting a wild bird. Is the end of the story that Milton Muncie's goose is a wild Barnacle Goose that likely came to Nebraska from the North Atlantic? There is one final twist. Upon reviewing the specimen, it was determined that this "Barnacle Goose" was, in fact, a hybrid. Making absolute conclusions about parent species of avian hybrids can be a risky venture, but plumage characters suggest this goose is a Barnacle x Cackling Goose hybrid; the latter species was previously known as the small form of the Canada Goose. Interestingly, the goose was harvested in a flock of Arctic-breeding Cackling Geese, or hutchies, as they are sometime called. As Cackling geese are rarely (if ever) kept as exotic pets in North America, the case for a wild origin of this hybrid specimen only grew stronger. Nebraska has no other accepted records of Barnacle Goose, but the evidence this bird possessed in its feathers shows wild birds are capable of migrating to our state. It is a story that was just waiting fifty years to be told. A more complete summary of this study is presented in a recent edition of the Nebraska Bird Review. Wildlife Conservation Fund Helps Solve Goose Mystery By Joel G. Jorgensen, Nongame Bird Program Manager, Nebraska Game and Parks Commission Scientific analysis of feather samples from this Barnacle Goose harvested in 1968 revealed important clues about its origins. JEFF KURRUS, NEBR ASK ALAND This 50-plus year old mount was originally identified as a Barnacle Goose – we now know it's true origins...

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