Farrar Pond hosts resident Canada geese (Branta canadensis) from spring’s first persistent open water to final closure a few weeks from now, and much larger populations of transients as the seasons shift. Harold here offers us some fine shots of geese on the wing.
While geese cannot soar great distances at perfect rest, as can gyrating scavengers like the buzzard (utilizing thermal lifts) or extreme sea voyagers like the albatross (near-surface wind shear), they do fly efficiently, with a glide ratio estimated around 20:1. There is a widespread factoid—based on sound but highly approximate calculations and then over-generalized—that by flying just so in V-shaped “skeins” the flock can fly 71% further than individuals could alone with the same energy expenditure. A more cautious view, which includes an above-average explanation of how formation flyers can benefit from wingtip vortex shedding of those ahead to mitigate induced drag may be found here. And similar benefits are posited for coordination instinctive in schooling fish and calculated for wind farms.
-Ed.
Not geese, but quite a gaggle of invasive European starlings!