Bufflehead - Photo: Dow Lambert
Bufflehead
by Bob Boekelheide
November 2020
Do you know which species consistently ranks as the most abundant "diving duck" on the Sequim-Dungeness Christmas Bird Count (SDCBC)? Is it Surf Scoter? Common Goldeneye? Red-breasted Merganser? Nope. The most abundant diving duck on our Christmas Count is the humble little Bufflehead. It's time to pay homage to this wonderful little duck, which arrives for the winter right now in October and November.
Our record SDCBC Bufflehead count is 3362, tallied in 2001. Last year, on the 2019 SDCBC we counted 1757 Buffleheads, which turns out to be slightly below our 35-year average of 1895. There are likely many more Bufflehead out there that don't get counted. The SDCBC Bufflehead count almost always scores in the top five counts in Washington State, competing with places like Olympia, Padilla Bay, and the San Juan Islands for highest number. The highest count for North American CBCs often goes to Point Reyes, CA, where they sometimes tally over 10,000 Bufflehead.
How consistent is our Bufflehead CBC count from year to year? Figure 1 shows a graph of the number of Buffleheads counted per party-hour on the SDCBC over the last 35 years. I used the number of Bufflehead counted per party hour rather than the actual counts, to standardize our count effort between years.
From Figure 1, it looks like our Bufflehead counts may have declined slightly over time, but even so Buffleheads ranked as our most abundant diving duck in 33 out of the 35 years. In the two years when Bufflehead was not the most abundant diving duck, the top scoring diving duck species was none other than Surf Scoter.
When do Buffleheads occur around here? Figure 2 shows the annual cycle of Buffleheads in Dungeness Bay, based on data collected by OPAS volunteers as part of the Three Crabs Bird Study from 2014 to 2018.
To gather these data, we counted birds three times each month between 2014 and 2018, viewing a designated area of outer Dungeness Bay from the beach at Three Crabs. Figure 2 shows the highest monthly counts rather than average counts, to illustrate the peak numbers we saw in the count area within each month.
FIrst, notice that we didn't record any Buffleheads between June and September, when they nest by ponds and lakes in the taiga forests of Canada and Alaska. Buffleheads are cavity nesters, using tree holes made by Northern Flickers to lay their eggs. It is thought that Buffleheads are almost entirely dependent on flickers to provide their nest holes.
Buffleheads consistently arrive here for the fall in mid-October. They arrive in mass, so their numbers in Dungeness Bay quickly go from zero birds to a few thousand birds by early November. In the spring they trickle away a little more slowly, likely because different-aged birds return to breeding areas at different times, with younger birds possibly hanging out longer before heading north.
Bufflehead (female) - Photo: Bob Boekelheide
It seems curious that we recorded fewer Buffleheads in January compared to the other winter months. Their annual cycle graph (Fig. 2) looks bimodal, or two-peaked, showing one peak in December and one peak in March, with a noticeable dip in January. Are there really fewer Buffleheads here in January? One explanation is that maybe Buffleheads gather here first in fall, then keep going south to Oregon and California (like Point Reyes?) in early winter, then return to Dungeness Bay on their way north in February and March. Another possibility is that these birds move around Dungeness Bay depending on tides and other factors. During winter, daytime tides are mostly high, so it is possible that these diving ducks move elsewhere inside Dungeness Bay to feed where depths are more shallow at high tide. Of course another possibility is we just missed the birds. Likely the only way to answer the question is to put transmitters on individual birds and see where they go during winter.
Bufflehead (male) - Photo: Dow Lambert
Bufflehead feed on the bottom in fairly shallow water, so nearshore areas of the Pacific Northwest are perfect for these little ducks. They feed on a variety of crustaceans, mollusks, and some fish and fish eggs. Apparently one of their favorite foods is shrimp. Picture in your mind all those little Buffleheads swimming around the bottom in Dungeness Bay picking juicy little shrimps off the sandy substrate.
One interesting finding is that Buffleheads may be faithful to both their nesting sites and their wintering sites. Banded bird studies show that females return annually to the same nest hole or close nearby. Other banding studies show that some birds migrate to the same exact location every winter. Those little Buffleheads you see this winter by John Wayne Marina could very well be the same ones you saw there last winter.
How long do Buffleheads live? On average, not very long. Calculations with birds banded as adults show that the average male Bufflehead lives only 2.5 years and the average female lives 2.3 years. But some individuals live a surprisingly long time. The oldest female on record was at least 11.5 years old and the oldest male was 18.7 years old.
Finally, one of the most impressive items I discovered while researching this report is that the city of Sidney, British Columbia, has male Buffleheads on its coat of arms. They selected Buffleheads because of their "vivacity and boundless energy." Buffleheads are also known as "Spirit Ducks," possibly because they have an amazing ability to quickly dive out of sight when someone shoots at them. Poof - they're gone.
The Sidney, British Columbia, Coat of Arms, showing a male Bufflehead on each side
This winter go closely watch a flock of Buffleheads and appreciate this wonderful little diving duck.