- Pets and Animals
The ivory-billed woodpecker was thought to be extinct, but a few seconds of video taken in 2004 and other recent evidence suggests it may still exist. The ivory-billed woodpecker is the largest woodpecker in the United States, and it looks very similar to the pileated woodpecker. This similarity causes a lot of confusion, and many ivory-billed sightings are actually pileated woodpeckers. There are two subspecies. One in the southeastern United States and one in Cuba. Although they look very similar, DNA evidence suggests the two subspecies actually split about one million years ago. Experts disagree on the existence of both.
Differentiating the Ivory-Billed from the Pileated Woodpecker
The Ivory-billed and the pileated woodpeckers look very similar. The ivory-billed is slightly larger. It is about two inches longer (20" versus 18"), has a slightly wider wingspan (30" versus 28") and about thirty percent heavier (500 grams versus 375 grams).
Both birds have black, white and red feathers, but there are subtle differences:
- The back of the pileated is mostly black, while the ivory-billed has a good deal of white (see graphic below)
- The aft edge of the wings is black on the pileated, and white on the ivory-billed.
- On the males, the forehead of the pileated is red, while the ivory-billed has a black forehead.
The calls of the two woodpeckers are also different. The only recordings that were definitely made by ivory-billed woodpeckers were recorded in 1935 by Arthur Allen and others from Cornell University. They made about five minutes of recordings in Louisiana. A few seconds of these recordings are available on the Cornell Lab of Ornithology website.
The ivory-billed woodpecker was never a common bird, but it was once had a considerable range throughout the southeastern United States and Cuba. In the U.S. it was found as far north as the Ohio River. Its preferred habitat is swampy old-growth forests. It feeds primarily on beetle larvae, and it ranges over large territories looking for dead trees where they are plentiful. Among Indians, their bills were highly sought items for personal ornamentation. They were traded throughout much of North America, far outside of their natural range. The ivory-billed woodpecker was first described by the English naturalist Mark Catesby. He reported that Indians in Canada would trade two and occasionally three buckskins for one bill. Catesby published Natural History of Carolina, Florida and the Bahama Islands in 1731 (volume 1) and 1743 (volume 2).
The ivory-billed woodpecker seemed to do okay until the later part of the nineteenth century, when timber cutters started felling trees in the old growth forests of the southeast. They required large tracts (estimated at six square miles in the 1930s) of mature forest to find enough beetle larvae to survive. Collectors also shot numerous ivory-billed woodpeckers. The species was believed to be extinct in the 1920s, until two specimens were shot in Florida.
The Singer Tract
Another ivory-billed woodpecker was shot in 1932 in Louisiana. This occurred in a large section of virgin timber along the Tensas River owned by the Singer Sewing Machine company and known as the Singer Tract. An expedition was launched in 1935 to search the area for remaining ivory-bills. This expedition produced the only verified audio and video recordings of the ivory-bill.
Jim Tanner, a Cornell PhD student, studied ivory-billed woodpeckers from 1937-1939 for his dissertation. He observed them in the Singer Tract & looked for them in other locations where sightings were reported. In 1939 he estimated there were only 22-24 left in the United States. He also believed there were no more than eight in any one location. Tanner never found any ivory-billed woodpeckers outside of the Singer Tract, This convinced him that it had to be protected or there was no hope for preserving the species.
Singer never allowed logging in this tract, and had wardens patrol the area. Unfortunately they sold the logging rights to the Chicago Mill and Lumber Company in 1937. Four governors and the Audubon Society wanted to purchase the tract and make it a preserve. The governor of Louisiana pledged $200,000 for this purpose, but the offer was rejected.
Richard Pough (He later became the first president of The Nature Conservancy) was sent by the Audubon Society in December of 1943 to see if there were any ivory-billed woodpeckers left. He found a single female in a small stand of timber surrounded by an area that had been clear-cut. Don Eckelberry, an Audubon Society artist visited the area in April of 1944. He found the bird Pough had sighted - This is was last time the ivory-billed woodpecker was sighted with certainty in the United States.
The Cuban Subspecies
The Cuban ivory-billed woodpecker suffered a similar fate. After the Spanish-American War in 1898, old growth Cuban forests were cleared to grow sugar cane. An ornithologist named John Dennis observed some ivory-bills in 1948, and published a paper about them. In 1956 a conservation plan was proposed, but the Cuban Revolution occurred before anything was done.
The last confirmed sighting of the Cuban ivory-billed woodpecker was in 1987. The Cuban government quickly protected the area where it was sighted. Unfortunately, 1991 and 1993 expeditions detected no trace of the birds. They are now believed to be extinct, although there is still some faint hope.
There have been reported sightings of ivory-billed woodpeckers in the United States since 1944, but most scientists considered it extinct. An expedition in 2004 in the Big Woods region of Arkansas found evidence of ivory-billed woodpeckers, including four seconds of video. After carefully examining the video, the searchers concluded it had white at the rear of its wings, and therefore had to be an ivory-billed and not a pileated woodpecker. Other scientists disagree. Later searches of the area failed to produce conclusive evidence and the existence of the ivory-billed woodpecker remains a hotly debated topic among ornithologists.