The Three-Minute Outdoorsman: Wild Science from Magnetic Deer to Mumbling Carp

34. What Little We Knew about the Labrador Duck Just Got Littler

t h e t h r e e - m i n u t e o u t d o o r s m a n 132 As an alternative, for example, one might suggest that the iris and eyelid coloration functions in the way in which ducks choose mates, sort of a Morse code for dating. Two winks means yes, one wink, maybe. However, in this case, the researchers noted that ducks have their eyes open during courtship. That right there might be a decent take-home lesson for humans. 34 what little we knew about the labrador duck just got littler We are all aware that the days of ducks filling the skies are long past. Still, seemingly good numbers are around, and none have recently gone extinct. This is not the case for the Labrador Duck, which was extinct by the late 1800s. Our knowledge of this bird is pretty fragmentary. For example, Audubon may have seen a nest of the species (in the nonbreeding season), but whether the nest he described is actually from this species is debated. So, no one is actually sure where the species’ breeding grounds were (“Labrador ” was kind of a guess). We know from museum specimens (fifty-five worldwide) that it wintered along the Atlantic Coast, from Nova Scotia south to Chesapeake Bay. A substantial number were collected near Long Island, New York. Some described the duck as common, others said it was rare, while still others described it as common at one time and then rare as market hunting reached its heyday. Some found the duck to provide an “excellent supper,” whereas others said the birds often hung in the New York City markets until they rotted. In any case, delectable or otherwise, they are extinct today. What caused their extinction is unclear. They were hunted for food on the wintering grounds, and indigenous peoples may also have eaten them where they bred. In the 1700s and 1800s, feather and egg hunters may have made an impact. The duck also had a very specialized bill, which I N T H E W A T E R 133 probably meant its food source was highly specialized and possibly made the species vulnerable. So, our knowledge of the Labrador Duck involves old, often conflicting reports and museum specimens. Until recently, these specimens included both museum skins and eggs. However, eggs of many species are not that easy to tell apart from the empty preserved shells in collections. So, the eggs thought to be from Labrador Ducks were perhaps misidentified. But given that the bird is extinct, how would we know? In a scientific study published in the ornithological journal The Auk, Glen Chilton, of St. Mary’s University College in Calgary , Alberta, and Michael Sorenson, of Boston University, tested Labrador Duck eggs to see if they were authentic. Chilton and Sorenson searched museum collections around the world and found nine eggs that were identified as those of the extinct Labrador Duck. Chilton extracted some of the dried egg membrane from the inside of each of the nine eggs (each at least 150 years old), which were in Germany (six), England (two), and Scotland (one). He sent them to Sorenson’s laboratory at Boston University. Sorenson then used some careful laboratory techniques to extract and sequence DNA from the membranes. It is well established that each species has a unique DNA fingerprint or profile, and Sorenson compared the sequences from the eggs shells to DNA sequences obtained from some of the old museum specimens (called study skins) of Labrador Ducks as well as other waterfowl species. The results were not good if you wanted to know what Labrador Duck eggs actually looked like. The DNA tests showed that the six eggs from Germany (Dresden) were produced by one or more Red-breasted Mergansers. The two eggs from England were produced by a Common Eider and Mallard, respectively. The Scottish egg was also from a Mallard. In every case, the range of the species that actually produced the egg overlapped with potential Labrador Duck breeding sites. Unfortunately, none of the eggs were from Labrador Ducks. Some of the confusion about the identification associated t h e t h r e e - m i n u t e o u t d o o r s m a n 134 with the old eggs comes from the common names people have used for birds...