For the past 20 years or so, coastal duck hunters have wondered why the flocks of teal that fluttered down to their decoys like falling leaves have all but vanished. Now, sea-duck hunters — not to mention guides — are wondering why the once-abundant rafts of eider ducks common to Maine’s coast are showing marked declines. Consequently, opinions and theories are flowing like the tides.
So, to trim the fat and get to the meat of the matter, I talked with wildlife biologist Brad Allen, head guide of the Department of Inland Fisheries and Wildlife’s bird group. In early January, flying with U.S. Fish and Wildlife Service biologist-pilot Mark Koneff, Allen completed the department’s annual aerial survey of waterfowl wintering on Maine’s coast. From Cobscook Bay to the New Hampshire border they cruised and counted, ending with a grand total of 53,817 — of which only 9,964 were common eiders. A sobering number, for sure, considering that 46,036 eiders were counted during the 2002 aerial survey.
Though eider numbers have fluctuated during the past decade, Allen’s concern for the current decline — last year’s count was 11,524 — was obvious when he told about flying over offshore ledges in the Addison area and seeing only one eider where usually there were hundreds. In affirming that nesting numbers also are down, Allen listed disease, predation, hunting pressure and the availability of feed (primarily mussels) as possible reasons for the not-so-plentiful eider population. “We’ve reduced the bag limits for sea-duck hunting,” he said, “and the only disease I know of is a virus in the Wellfleet area of Cape Cod.” It appears, however, that the virus isn’t affecting eiders thereabouts: last week Mark Koneff reported an estimated 38,000 rafted off the Massachusetts coast.
Allowing that the big sea ducks aren’t bothered by weather, Allen’s focus is on feed and predation. Accordingly, he hopes to initiate a dialogue with the Department of Marine Resources regarding the status of mussel stocks. For the most part, predation occurs on eider nesting islands, where herring gulls prey on eggs and black-backed gulls devour chicks leaving their nests. Conversely, Allen said predation of eagles on gulls was helpful, but more effective measures were needed to cull the voracious scavengers. In concluding, the veteran biologist said he thought the decline in eider numbers was a temporary shift that would be reversed by management and Mother Nature.
All told, the high point of the 2012 aerial survey was the increase in black ducks, from last year’s 15,302 to this year’s 19,320. As for teal, which depart on their southern sojourns with the first hint of frost, the chances of counting them in mid-winter are about as good as the chances of counting woodcock.
Tom Hennessey’s columns and artwork can be viewed at www.bangordailynews.com. Tom’s email address is firstname.lastname@example.org.