During the last few days of August, bird life on the Vineyard undergoes a dramatic and often rather sudden shift. Migratory birds, passing from their breeding grounds to their winter ranges, spike abruptly in prevalence. Numbers and diversity increase; the odds of finding something unusual multiply.
To be sure, migration has been under way for a while. Southbound shorebirds have gradually built in numbers since early July, and even a few transient songbirds have been evident. But to put it succinctly, we’ve just entered the peak season of a Vineyard birder’s year.
And the season started with a terrific find — not so much for its rarity as for its spectacular size and appearance. An American white pelican (no relation to the author!), roughly the fourth ever recorded on Martha’s Vineyard, was found in Chilmark on August 26.
Tipped off to the presence of a strange bird at Black Point Pond by Alice Early and Larry Hepler, Soo Whiting and Flip Harrington identified the pelican. The bird moved around a bit, but remained in the area for several days; as I wrote this column last Sunday, I hadn’t heard any recent reports, but this species often lingers for quite a while when it turns up as a vagrant. While getting to the bird posed some challenges, it has been seen by multiple observers, and resoundingly photographed.
Among the many waterbirds that have experienced a brush with extinction due to persecution, habitat loss, and toxins, American white pelicans are now reasonably plentiful across their extensive geographic range (one source puts their total numbers at about 125,000). As breeding birds, they are strongly colonial, with most nesting confined to a couple of dozen breeding sites, mainly on islands in lakes and rivers in the northwestern United States and southwestern Canada. (There are a few small colonies of nonmigratory birds on the Gulf Coast.)
White pelicans, despite their awkward, chunky build, are marvels in the air, furling their long necks, resting their bulky bills on their breasts, and covering huge distances when they want to with powerful wing beats and direct flight. They also soar like vultures, catching bubbles of rising hot air and often drifting upward until almost invisible from the ground. When traveling any considerable distance, flocks of pelicans (like many other large birds) often fly in V, or echelon, formation for aerodynamic efficiency.
Normally their migratory route takes them fairly directly from their breeding colonies to their wintering grounds in the extreme southern United States and Mexico. The Vineyard and the rest of New England sit squarely north and east of normal routes for this species, and hence white pelicans show up here mostly as individual birds that have either lost their way or, perhaps, decided to do some exploring. Such visitors are uncommon, but are spotted fairly regularly across our region.
Although a white pelican is not that unusual in Massachusetts, they’re still striking birds. It’s hard to do justice to the size of these things. A big male white pelican may weigh 20 pounds, stretch out to five feet long, and possess wings that span almost 10 feet. They’re noticeably larger than the familiar mute swan, and absolutely dwarf “big” birds such as gulls and Canada geese. As their name suggests, these birds are mostly white (and often appear totally white when sitting). But overhead, most of the trailing edge of their wings are black, a pattern that is virtually unmistakable.
Their appetites are commensurate with their bulk: A pelican will eat from two to three pounds of fish per day, a habit which has not endeared it to the aquaculture industry, catfish growers in particular, in areas where this huge bird winters.
While the pouch of skin under the bill is not used for transporting fish — pelicans swallow their prey before going anywhere — it does play a key role in foraging. Tipping up in the water or scooping, a pelican takes in a couple of gallons of water plus whatever fish come with it. The water is drained out through a partly opened beak, leaving just the fish to swallow.
While smaller fish make up the bulk of the diet of this species, one source cites a case of a white pelican downing a 27-inch prey item! White pelicans don’t plunge into the water like the related brown pelican, and so their foraging is limited to what they can reach from the surface — the top four feet or so of the water column.
Normally pelicans are strongly social birds, a proclivity that extends to their feeding: Pelicans often team up to herd fish into concentrated groups before scooping them up. They’re certainly capable of feeding on their own, but the Vineyard’s salt ponds may not represent very fertile fishing grounds for a bird this size. Oddly, I haven’t heard any reports of the Black Point Pond pelican feeding, which makes one wonder how the poor bird is faring.