‘Tis the season, the season for ducks. As November gives way to December, we are firmly within the waterfowl window here on the Cape and Islands, as well as the window when you realize you forgot to turn off your outside shower – you better go do that as soon as this piece is over. While some ducks have been here for a couple of months or more, numbers of most don’t ramp up until things get properly cold, right around now.
So it’s no accident that on this coming weekend, numerous enumerators of fowl will be afield to count all the ducks on the freshwater ponds of Cape Cod — it’s the 38th annual Cape Cod Waterfowl Census, overseen by Cape Cod Bird Club. While it’s always held the first weekend in December, in recent years we have discussed making the survey at least a week later, as the warmer winters keep ducks further north for longer. Both scientific data and the recollections of old timers agree — ponds don’t freeze up as early as they used to up north, meaning we may not see some ducks until January or later. This may partly explain the downward trend in duck numbers we see in this data set, as well as the fact that no one can ice skate on Cape Cod ponds anymore.
“Counting ducks? How hard can that be?”, you may ask, “Surely any idiot can count a few mallards and some Canada Geese?”. Aha — not so fast! In reality, it takes a very specific and skilled type of idiot to count waterfowl. Over the years, 41 species of ducks, loons, grebes, and other waterfowl have been tallied on this census, not including several species of gulls and some other oddball seabirds, like when little Arctic seabirds known as Dovekies were found on some ponds last year. That means you need to be ready to identify close to 50 species of waterbirds, some of which are not very cooperative, often hugging the far shoreline of big ponds, disappearing under water for minutes at a time, or hiding under overhanging trees and shrubs. Spotting scopes and experienced observers familiar with the behavior of different species are key for getting accurate data.
What might you see if you go a ducking this weekend? If you pay attention to freshwater ducks at all, even if you just dabble in the topic, you won’t be surprised that the top five species by numbers include Mallards, American Black Ducks, Canada Geese, and Buffleheads. But you may be surprised that the scaup, two species of sparsely distributed diving ducks that prefer just a few specific ponds, outnumber all of them. The two scaup species, Lesser and Greater, are so tough to separate that most observers wimp out and just call them “scaup species”, probably after muttering something about the sun being in their eyes or how far away they were. But you likely won’t have to worry about separating them, as the vast majority of scaup crowd onto just on a handful of mussel-rich ponds in Falmouth and Harwich, often in flocks of over 500.
The aesthetes out there will appreciate a good look at Hooded Mergansers and Wood Ducks, two of the better-looking birds anywhere, in my opinion, and two species showing upward trends in the census data. Check smaller, wooded ponds for these lookers. Wood Ducks are scarce, but ponds replete with minnows and crayfish may hold dozens of Hooded Mergs, as we call them — in fact, they are the sixth most abundant species on the annual census, often topping 1000 individuals, Cape-wide.
Pond-wise, bigger ones with herring runs and vegetated shorelines are typically the best for waterfowl diversity, hosting fish for the three types of mergansers and two loons, mussels for the scaup and Ring-necked Ducks, and aquatic plants for the dabblers, like Mallards, wigeon, teal, and coot. But there are small, potent ponds that host several species, and sometimes offer closer looks, so check them all. And if you happen to see any of us skilled waterfowl enumerators, do say howdy.
