Buffleheads: The World’s Most Punctual Bird

If you’ve been out exploring the coastal bays of Mayne this winter, did you happen to notice a black and white bird the size and shape of a bathtub rubber ducky buoyantly bobbing up after a dive? These little sea ducks, Buffleheads, are beautifully patterned: males have iridescent purple heads, dark upper parts decoratively striped with white bars, and eye-catching bright pink feet. Females are more subtle in appearance, with a soft grey-brown body and distinctive white cheek patch. Their colourful feet propel them through water as they dive, folding their wings back against their bodies, but are not made for walking. Buffleheads are generally only seen on land escorting their ducklings from nest to water. 

The Bufflehead is Canada’s smallest diving duck (which differ from dabbling ducks who tip up and down to feed rather than submerging themselves), and form small flocks of up to ten birds seen here only in non-breeding season. They are often spotted alongside their cousins, the Goldeneyes, where they dive for food such as shrimps, crabs, sea snails, and the seeds of aquatic plants.

Winter Courtship

While wintering here, they also engage in courtship as they aim to pair off before heading to their breeding areas. The males put on quite a display, bobbing their heads up and down and making other jerky movements. To really impress a potential mate, they fly over her, fluttering with wings and tail low, and then land in a water-skier fashion to show off those sexy pink feet. If you’ve ever seen some vigorous splashing involving Buffleheads, it would have been a drake shooing away other suitors by rushing over the water’s surface.

Bufflehead are one of the scarcer ducks in North America with numbers around 1.4 million (2015). They are found in scattered flocks coast to coast in Canada during breeding season, but migrate south during winter to saltwater bays. Buffleheads that breed west of the Rocky Mountains winter on the Pacific coast, and those in central Canada migrate southeast. Here in BC, they fly across the coastal mountains at high altitudes reaching amazing speeds of up to 77 km/hr. These ducks breed near ponds and lakes in mixed conifer and aspen forests, and their range is limited by the distribution of the Northern Flicker. 

Cavity Nesters

We learned in an earlier article on woodpeckers how important tree cavities are to other species, and Buffleheads are a case in point. Females lay their eggs in holes excavated by Northern Flickers, as they are the smallest tree-nesting duck and therefore the only ones that can fit in these smaller cavities. (Other tree-nesting ducks use holes from pileated woodpeckers and larger excavating species.) A female will typically lay a clutch of 5 to 11 buff-coloured eggs, though sometimes more than one bird will use the same nest, so there can be up to 20 eggs in one nest. To make the nest cosy for their young, females pluck out some of their own chest feathers. Incubation is about 30 days, and the ducklings only stay in the nest for a couple of days before they are led to water.  The female tends her young ducklings for a month, keeping them warm and safe from predators. Sadly, the treacherous journey from nest to water, and spells of severe cold weather and attack by predators mean that only half the young survive to the age of 8 weeks. During the summer, adult birds are undergoing their annual moult which leaves them flightless for around three weeks. By renewing their body plumage and building up fat reserves, Buffleheads are better equipped to face their fall migration. Males leave their mates during incubation and moulting, but return to the same partner for several years.

All Buffleheads Day

During the middle of October, Roberts Bay near Sidney sees the arrival of flocks of Bufflehead, and residents there have a celebration, “All Buffleheads Day”, to mark the occasion. Extraordinary as it may sound, these little birds arrive with clocklike regularity on the 297^th or 298^th day of the solar cycle (October 15^th or 16^th). The science behind this is too much for this writer, but Victoria biologist Kerry Finley explains it here for those with bigger brains:

“All Buffleheads Day, the 297th day of the solar year (typically October 15th) is a constant based on 22 years of observation in Shoal Harbour Migratory Sanctuary, in Sidney, BC … The variation around All Buffleheads Day (ABD) is very small (+/- 4.14 days based on 23 years of constant observation). This precision is a world record in timing but, more importantly, the variation is non-random and predictable. All Buffleheads Day is a national event because Bufflehead migrate at the same time from coast to coast. It is an international, circumpolar phenomenon because weather and climate have no boundaries, and it’s universal because planetary waves are universal.Remarkably, Buffleheads have never appeared on the day before ABD, referred to as Null Bufflehead Day or NBD. This is thought to represent a quasi-stationary resonance point of the planetary Rossby waves [large internal waves of the oceans and atmosphere caused by the Earth’s rotation] influenced or ‘strummed’ by the lunar cycle. Thus, Null Bufflehead Day represents a real date in a natural calendar, the constant, resonant, planetary phenomenon, that explains ABD, and the onset of winter. After ABD, Buffleheads arrive in two waves associated with increasing amplitude of the planetary waves, in resonance with the lunar cycle, creating stormy weather.”

[Excerpt taken from https://www.gvnaturehood.com/post/celebrating-the-return-of-the-bufflehead]

A local group in Sidney, The Friends of Shoal Harbour, have been celebrating this special day for over ten years, highlighting the importance of conserving the habitats these birds need to feed and overwinter. Shoal Harbour is now part of the Sidney Channel Important Bird Area (IBA), recognising its importance as crucial bird habitat. 

Bufflehead Status

In contrast to many other duck species that have declined in recent decades, Bufflehead numbers have remained relatively constant. Habitat degradation is the major threat to this bird as they cannot nest on prairie or tundra habitats, and must have tree cavities near water without too much ground vegetation so the ducklings can travel safely from the nest to water. Pike and other larger predator fish find chicks to be a perfectly sized meal, but many human hunters do not favour the adult birds as they are too small for a family dinner and taste rather strongly of the salty seafood they consume over the winter months. Yet, despite this fact, approximately 200,000 Bufflehead are shot by hunters annually. As well as large freshwater predator fish, birds such as Peregrine Falcon, Bald Eagle, Red-tailed Hawk and Cooper’s Hawk also prey on these little ducks.