The Northeast Region's headquarters in Hadley, Mass., will host the exhibit through February. Then it will return to the John Heinz refuge for display during International Migratory Bird Week (May 8-14) and remain there throughout the spring.

Every spring, Buchanan photographs the beaches of the estuary, where the high tides at full moon signal the spawning of the largest population of horseshoe crabs on the planet. The female horseshoe crab comes ashore on the incoming tide with a male in tow to fertilize the several thousand eggs she will lay before departing on the outgoing tide. Many of the eggs will hatch in a few weeks into tiny, translucent replicas of their parents. But many more, exposed by the ebb and flow of the tides, will serve as a huge source of protein for tens of thousands of shorebirds that have exhausted all their reserves in perfectly timed migrations over thousands of miles from their wintering grounds in South America.

Buchanan worked as a freelance writer and photographer for more than 15 years before he joined the refuge staff in 2000. A big part of his beat was the Delaware Estuary. Of his affinity for photographing what some consider little brown and gray birds, Buchanan says, "For me, they are like angels made of fine tweed: wonderfully muted tones and hues, occasionally highlighted with a splash of vibrant color just to keep you guessing."