December 2019 Lloyd Center Waterfowl Count – Geese Stay in Fields and Diver Diversity Increases

by Jamie Bogart, Lloyd Center for the Environment Research Associate

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A year ago, the 2018 December waterfowl count was postponed a week to December 9th, enough time for temperatures to drop and cause an influx of birds seeking unfrozen waters. This December, Lloyd Center staff and volunteers surveyed the estuaries and coastal ponds from Sakonnet Point in Rhode Island to Padanaram in Dartmouth on the scheduled date, December 1st, as part one of the 33rd Annual Lloyd Center for the Environment Winter Waterfowl Survey.

Morning conditions on December 1st were sunny and seasonable with no major tidal influences impacting the count. Ice coverage was lower than last season but still higher than most December counts within the past decade, so migrants from the northernmost boreal regions where waters always freeze were present. A slightly warmer trend however, surely kept some birds in their freshwater breeding grounds. The lack of snow cover also meant Canada Geese had access to grassy forage in the buffer zone surrounding estuaries. The presence of a small number of Snow Geese mixed with a Canada Goose flock in the fields bordering a system, is indicative of the importance of field habitat to wintering waterfowl, even if the birds aren’t counted. Not unexpected, total waterfowl counted (4,549) was a huge decline from last December’s record count (8,494), with this year’s count more average for December. Recall last year featured one of the highest goose counts on record (3,120), which declined to only 1,284.

American Black Duck and Mallard also declined considerably, along with slight declines in abundance of the relatively common American Wigeon and Northern Pintail. Black Duck and Mallard breed more locally and can remain on any unfrozen fresh water due to warmer temperatures than the far north. Some dabblers, particularly Widgeon, may also feed in fields along with geese. However, the common waterfowl that declined still determined the site with the most birds, which this year was Nanaquacket Pond (516) in Tiverton, the site with the highest Canada Goose total (241) and next highest Mallard total (147) to Nonquit Pond (192). Both ponds have human-made restrictions to estuarine flow which attract high numbers of Mallards. American Black Duck numbers were highest at Allens Pond, an intermittently flooded system without human-made restrictions to estuarine flow, the preferred winter habitat of the secretive Black Duck. Incidentally, Allens Pond was historically studied to assess its importance to Black Ducks and was the site which started the Lloyd Center winter waterfowl effort.

Most of our divers breed further north into Canada and are therefore more reliant on open water further south, which was slightly more available this year. This helps explain the increase in our most common divers, Bufflehead and Red-breasted Merganser. Hooded Mergansers, which breed more locally, declined slightly, again likely due to warmer temperatures locally. However, the tendency of “Hoodies” to utilize small creeks and generally hidden areas can make them even harder to detect than Bufflehead when more open water exists, so numbers could be higher than our count suggests.

The bigger story for divers in this count was a small increase in some less common pond-dwelling species including Ruddy Duck (114), Common Merganser (17), and Canvasback (8), with only Ruddy Ducks (8) present last December. The flock of Canvasbacks, while small, is significant as a species considered nearly extirpated from the region, with this being actually the highest December count since the late 1990’s. The Common Mergansers were seen in Nonquit Pond, with both “Ruddies” and Canvasbacks present in Richmond Pond. Ruddies were also present to a lesser degree at neighboring Cockeast Pond. Although other waterbirds aren’t included in the totals, 415 American Coot counted at Quicksand Pond is noteworthy as no coot were counted last December.

Richmond, Cockeast, and Quicksand Pond were almost entirely frozen last season, but had almost no ice for this survey. For this count only the smallest systems froze, leaving large coastal ponds available for use by migratory diving ducks. Will open water be filled with a higher abundance of ducks expected for the January count including less common divers? Or will ice and snow be the story of the day with no birds as far as the eye can see? Stay tuned for the results of count two in January!