The Least Bittern
(This column was first published in the July 21, 2003 issue of The Buffalo News.)
Most of us are familiar with the great blue heron, the largest and most commonly seen of our local herons. We often observe it either standing absolutely still at the edge of a marsh or slowly flying overhead, its neck folded back into an S-shape and its long legs trailing behind.
Far fewer know of the heron at the opposite end of the size scale: the least bittern. And fewer still have ever seen this tiny swamp dweller.
Tiny indeed. The least bittern is scarcely larger than a robin. Even that scrawny great blue heron weighs over forty times as much and the heron nearest its size, the green heron, is still three times as heavy.
For that reason, even though I am familiar with the least bittern, seeing one always comes as a surprise to me, even a shock. It is so remarkably downsized it seems like an escape from a circus sideshow; it is the Tom Thumb of the herons, a tiny model of what we have come to expect.
Look for least bitterns in cattail marshes. Like the rails that frequent the same areas, they occasionally venture out to the pond edge. Scan those edges regularly and you will occasionally see one either stepping daintily on the muck, wading in shallow water or straddling between two reeds.
You'll know it by its heron-like appearance and its size. It has a dark back and crown, light buff-colored breast and a matching buffy wing patch. That wing patch will distinguish it from the similar-sized all-dark rails. It appears as a light forewing and is especially apparent when the bird is in flight. And one sometimes pops up out of the cattails to fly a few dozen yards before dropping down out of sight again.
There is also a rare chestnut-breasted color phase that was formerly called the Cory's least bittern.
The least bittern is a bird more often identified by its call. Although it has other notes, its three syllable dove-like coo-coo-coo is distinctive. In spring it responds readily to a taped or even human imitation. This call is an extreme departure from the bog-pumping ung-ka-chunk call of its relative, the American bittern.
I have occasionally seen least bitterns at Tifft Nature Preserve but I have better luck looking and listening for them in the Iroquois and Tonawanda Wildlife Refuges, especially in the marshes along Meadville Road just south of Route 77.
The least bittern is listed by the U.S. Fish & Wildlife Service as a "species of management concern" and in New York it is considered threatened. I am pleased therefore to read in an article about this species by Heidi Bogner and Guy Baldassarre published in a recent Wilson Bulletin that they were able to find and study dozens of these birds in the Iroquois-Oak Orchard-Tonawanda marshlands. I find this another response to those who believe that these state and federal lands serve only the hunting, fishing and trapping communities. As Iroquois manager Bob LaMoy regularly insists: refuges serve wildlife first, people second.
In both 1999 and 2000, Bogner and Baldassare recorded two dozen successful and one dozen unsuccessful nests which suggests that these birds are doing reasonably well in these marshes. But life is threatening to the tiny chicks: they must avoid a litany of enemies including hawks, raccoons, snapping turtles, coots and geese. Of the average five eggs per nest less than half matured to be able finally to fly on their own.
A more serious concern: none of the birds trapped one year were recaptured the next, indicating a very low over-winter survival rate.-- Gerry Rising