Bird of the Month - October 2003
 

Buller's Shearwater
Puffinus bulleri

by David Fix

 ‘Globalization’ was expressed by the distribution of life long before the WTO fought for the corporate right to Pepsify the world.  Among birds claiming a great share of territory are the tubenosed swimmers, or ‘tubenoses.’  The extent to which members of this group have found niches in every ocean is wondrous.  Tubenoses varying in size from the Least Storm-Petrel to the largest albatrosses occupy oceanic waters in great variety.  The Southern Ocean, nearly contiguous through the mid- and higher latitudes and studded with islands, hosts the largest number of these birds.  Many tubenoses nest at only a few locations, yet disperse northward across the Equator in annual migrations which carry individual birds thousands of miles.  Among these wanderers is Buller’s Shearwater (Puffinus bulleri), an attractive seabird which occurs over the ocean opposite the Redwood Region from late summer through late fall.  Numbers are thought to vary from year to year.

Portraiture in the field guides suggests that Buller’s is boldly-patterned.  Indeed they are quite striking.  Impossible to convey in the pages of any bird book is the grace and economy of their flight.  No matter how impressed one may be with the flowing progression of Sooty Shearwaters, one’s judgement of grace on the wing is recalibrated when a group of Buller’s Shearwaters comes within sight.  Their movements are superb, each bird arcing and tilting in turn, seemingly without effort.  The first Pink-footed Shearwater or Pomarine Jaeger seen on a birding boat trip is noted with a shout and a nod;  the day’s first Buller’s Shearwater is met with concerted gestures toward “Three-o’clock, right THERE!” followed by a charged moment of congratulatory merriment.

Adding charisma to the allure of such streamlined and showy birds is their vastly remote breeding range.  Buller’s Shearwaters nest in burrows on the Poor Knights Islands. off New Zealand.  Dense concentrations of shearwaters there were ravaged by introduced pigs.  After eradication of the pigs the shearwaters rebounded, with the population estimated at two million.  Following nesting, Buller’s move northward on a circuitous route through the North Pacific, reaching northward to the cool waters off British Columbia and the Pacific States.  Though they aren’t classic deep-water seabirds, most nevertheless remain out of sight of our shores.  Most are encountered over the mid- and outer continental shelf.  Skillful and cautious birders scanning the ocean with a scope occasionally spy one or more of these shearwaters from coastal points, typically near the limit of identification but sometimes only a mile or so offshore.

No other shearwater looks quite like the Buller’s.  They are distinctively gleaming white below on body and underwings (shore-based birders beware pale fulmars!), black-capped, and have a strange and arresting upperwing pattern of dark coverts and outer primaries.  The balance of the upperparts is pale gray.  The bill is thin and black.  Buller’s Shearwaters are nearly a ‘sure thing’ on boat trips going offshore in September and October—fortunate are those persons who encounter a nearly pure flock, lifting from the ocean’s surface and flying off in synchronized passage across the swells.  Birds lagging behind the main seasonal dynamic have been observed in some years as late as December.