Gene Sparling, whose sighting sparked the search, paddles through the Big Woods.

Filmmaker Timothy R. Barksdale explores Bayou DeView near Brinkley, Arkansas.

David Luneau prepares a motion sensing camera used in the search for the ivory-bill.

Camouflage is a key to spotting birds without being seen.

Cypress trees and tupelo gums (pictured above) are ubiqitous in the swamps and bayous of the Big Woods.

Members of the search team survey an area of open water, Cache River NWR.

The White River, near Wattensaw Wildlife Management Area.

Bayou DeView, near Brinkley, Arkansas.

Gene Sparling compares a hole to a chart of historic ivory-bill and pileated woodpecker holes.

The search team packs up their gear after a day on the water.

David Luneau pauses to listen for sounds of woodpeckers.

Dutch scientist Martjan Lammertink.

Bobby Harrison, a professor from Oakwood College in Hunstville, Ala., was one of the first researchers to spot the ivory-billed woodpecker in Arkansas.

Gene Sparling continues his search.

Scott Simon and Timothy Barksdale study birdlife in the Cache River NWR.