from KJ Finley
The Bufflehead – Heerman’s Gull phenogram
Phenology is the root of natural history and our base instincts, if we are so attuned. How to predict when and where a biological event will occur, is essential to survival.
Phenology was the rage in Darwin’s time, but it has been all but expunged from our lexicon, as natural history became fragmented by disciplines. Recently it is enjoying a comeback, under the banner of citizen-science, in the new age of the Anthropocene.
Buffleheads (Bucephala albeloa) have been around for half a million years, since the late Pleistocene, and their predecessor B. fossilis, for two million years or so, since the late Pliocene. Along the way they took up an inextricable relationship with a desert, ground-feeding, ant-eating woodpecker. Like the Gilded Flicker or Gila Woodpeckers nesting in Saguarros and in soft Cottonwood Poplars along desert streams. These evolved into a Northern Flicker, strongly associated with the northern softwoods, especially aspen. These became our western red-shafted and eastern yellow shafted forms, split by Wisconsian ice sheets, and re-joined along the opening corridor following the “Yellowhead route” of the jetstreams.
The timing of their migrations is built into their DNA. They are exquisitely aware of weather patterns conducive to migration. From this perspective on their wintering grounds, they can be characterized as “last to leave, last to return”, which is dictated by their high energy requirements and the timing of the ice free season on northern breeding grounds.
Given concerns about the impact of global warming, I’ve been asked whether I have observed changes in their timing over the last two decades. In my published account of the first decade, and based on records from throughout the last century, and Tony Erskine’s pioneering studies of migration in the early 1960s, I concluded that there had been no apparent change in the timing of their first appearance ( All Buffleheads Day), nor in their subsequent influxes – generally two waves – ending in early November. This conclusion was supported by the research of Claude Duguay (2007), who found that though the open-water period was now longer in Western Canada, with earlier springs, the timing of autumn freeze-up seemed more fixed.
This year marks the 20th anniversary of monitoring their first appearance, and the resultant phenogram, follows in the wake of a major El Nino. I’ve not had time to fully analyze the results, so I’ll just throw it out and caution against conclusions. However it is apparent that their arrival schedule is different from last year’s El Nino, with a low first pulse and late, prolonged last pulse. In spite of prospects of an early winter on the northern plains, the Buffleheads stuck it out late, and farmers were able to salvage some of their crops after the early October snow. Latest statistics confirm that it is one of the warmest autumns on record in North America.
This is apparent in the EOSDIS imagery showing Big Quill Lake open as late as December 5th. The length of the open water season (217 days) is well above the long–term average of 193, but within the range of maximums ( record of 218 days in 1968). In general it appears that freeze-up has extended later, but it appears that break-up has not occurred earlier than the long-term. This may be due to the chemical nature of Big Quill’s sodium sulphate brine (See attached image with Quill Lake holdings its ice after most bodies are open. )
Finally, for this Senorita La Nina season, I dress up this festive phenogram with the signature of the Heermann’s Gull from Surfside’s Isla Rasa IBA site. Here the Sonoran-Boreal signature overlaps.