Since December 1988, the Lloyd Center has surveyed wintering waterfowl in estuaries from the Sakonnet River in Rhode Island to Apponagansett Bay in Dartmouth, Massachusetts.
In what started as an effort to determine the importance of Allens Pond Estuary to the American black duck, a migratory dabbling duck relying exclusively on estuaries for its intertidal food source, the waterfowl survey has become both an enjoyable opportunity for long-time volunteers, and a crucial inventory of a premier bird assemblage in southeastern New England. Once bodies of freshwater freeze further north, many duck species breeding in forested freshwater wetlands depart south to our estuaries which rarely ice over. But estuaries do partially freeze, and tide and weather conditions can influence survey outcomes, so both an early December and a late January or early February survey are conducted. On the two Sundays, volunteers venture out to survey, then stop by the Lloyd Center for Mark Mello’s famous linguica stew, and provide us with their count results.
A large diversity of wintering ducks features divers such as bufflehead, and red-breasted and hooded merganser, each of which enjoy more secluded portions of estuaries. Closer to the sea at the mouths of systems one commonly finds sea ducks such as scoters , scaup, eiders, goldeneye, and long-tailed duck. When large salt ponds aren’t frozen, ruddy ducks are yet another of many species one may see in addition to the abundant black duck, gadwall, American widgeon, green-winged teal, increasing numbers of migratory Canada geese, and congregations of the resident mute swan. Loons and grebes also mix amongst the ducks, geese, and swans, adding to the diversity.
Winter Waterfowl Update – February 2009
If there’s any doubt about this year’s groundhog prediction for an extended winter season, perhaps the latest count for the annual Lloyd Center Winter Waterfowl Survey provides data supporting the assertion.
Volunteers and Lloyd center staff kicked off February by visiting local estuaries in continuation of the ongoing assessment of habitat use by wintering waterfowl in our region. February 1, 2009 was a beautiful winter day featuring moderate temperatures but also vast stretches of the ice that has characterized much of this overall cold winter.
Significant ice is almost always an influence for the second count which is held over a month after the winter solstice, but ice was especially widespread this time around, many coastal ponds discovered as 100% frozen.
Although ice often forces waterfowl further toward the unfrozen ocean shoreline, ice is not necessarily a deterrent. Birds are often seen resting in large flocks on ice like ice fishermen at rest between feeding episodes, especially if an accessible area of water exists for feeding. Adaptable species such as Canada Geese also feed in exposed agricultural fields available often times even during icy periods.
The 4,589 total waterfowl counted for this survey is comparable to the 4,044 total counted for the Fall portion and far lower than last February’s 7,073 total. These trends show that this year numbers did not increase as usual, and that ice caused by colder temperatures is a significant factor.
Species-specific trends comparing this count to the survey held exactly one year ago include decreases for bufflehead (-767) Canada geese (-717), American black duck (-424), mallard (-190), red-breasted merganser (-148) and pintail (-77).
Increases occurred for two species commonly seen in open bays, common eider (+206) and brant (+72). Mute swan (+79) and common merganser (+30) also increased slightly. The slight increase in numbers that occurred since the fall segment of this survey consisted primarily of Canada Geese, perhaps partially due to their ability to find non-estuarine food sources on land.
While these periodic updates provide a snapshot of waterfowl populations and offer some insight as to why levels of abundance change for certain species, more long-term analyses paint a clearer picture.
The summation covering two decades of data about winter waterfowl habitat use in estuaries in our region that started a year ago and has now resumed will shed light on this precious natural resource.