Click here to view the manuscript that was accepted for publication.

The movie files.

Movie S2 The short flight in the 2006 video. The deep and rapid flap is inconsistent with Pileated Woodpecker but consistent with the physiology and historical accounts of the Ivory-billed Woodpecker. The movie plays at half speed and is sampled at 60 frames per second.
Movie S3 The takeoff into level flight in the 2006 video. The deep and rapid flaps are inconsistent with Pileated Woodpecker but consistent with the physiology and historical accounts of the Ivory-billed Woodpecker. The movie plays at half speed and is sampled at 60 frames per second.
Movie S4 The takeoff into level flight in the 2006 video. This version was modified to eliminate the effect of zooming the camera when the flight of the bird was detected. Although the quality is lower, this version shows more of the flight. The movie plays at half speed and is sampled at 60 frames per second.
Movie S5 A short flight by a Pileated Woodpecker, which does not require deep and rapid flaps. The movie plays at half speed and is sampled at 60 frames per second.
Movie S6 Takeoffs into level flights by Pileated Woodpeckers, which do not require deep and rapid flaps and have relatively low flap rates. The movie plays at half speed and is sampled at 60 frames per second.
Movie S7 A swooping takeoff from a high perch in the 2007 video. The bird appears in the upper right at the beginning of the movie and appears in the lower left at the end of the movie. The path of the swoop is far behind the trees in the foreground, and the bird is hidden by vegetation through part of the swoop. The movie plays at half speed and is sampled at 60 frames per second.
Movie S8 Takeoff into level flight in the 2007 video. The deep and rapid flaps are similar to those in the 2006 video. The popping sound at takeoff could be a wing hitting a tree branch. The movie plays at half speed and is sampled at 60 frames per second.
Movie S9 An upward swoop and landing in the 2007 video. A great deal of white appears on the ventral sides of the wings at landing. The movie plays at half speed and is sampled at 60 frames per second.
Movie S10 Dorsal view of the bird in the 2008 video showing large white patches on the wings. The movie plays at half speed and is sampled at 60 frames per second.
Movie S11 A putative double rap in the 2008 video (good speakers and high volume are required). Immediately after the raps, the camera pans toward the direction from which the bird appeared 77 s later. The movie plays at full speed and is sampled at 30 frames per second.
Movie S12 The bird and its reflection off the water as it approach the observation tree in the 2008 video. The wings are folded close to the body in the middle of the upstroke. The movie plays at half speed and is sampled at 60 frames per second.
Movie S13 The reflection of the bird just after it passed the observation tree in the 2008 video. The wings are folded close to the body in the middle of the upstroke. The movie plays at quarter speed and is sampled at 120 frames per second.

The figures.


Figure 1. Frames of a short flight in the 2006 video that are separated by 16.7 ms. The deep and rapid flap is inconsistent with Pileated Woodpecker, which requires little effort to take short flights, but is consistent with the physiology and historical accounts of the Ivory-billed Woodpecker.


Figure 2. Images from the approach of the 2008 video (left column), photos of Ivory-billed Woodpeckers by James Tanner (center column), and images of the reflection of the bird off the water just before it passed beneath the observation tree in the 2008 video (right column). In the image on the upper left, the wings are folded near the body as in the upper Tanner photo. In the image on the lower right, the wings are swept back as in the lower Tanner photo. In the image in the upper right, the long tail is consistent with Ivory-billed Woodpecker. The Tanner photos are in the possession of the U.S. Fish and Wildlife Service.


Figure 3. Wingtip elevation and wingspan (digitized and graphed by Bret Tobalske) as the bird approach from down the channel in the 2008 video. The shaded areas indicate brief intervals during which the wings were held fixed during the middle of the upstroke.


Figure S1. Sonograms of three putative kent calls recorded in Florida [3] (top) and two high-pitched calls from the 2006 video (bottom). The horizontal axes span 9 s. The vertical axes span 5.5 kHz. The high-pitched calls are composed of harmonics at 2.35 and 4.70 kHz. The simultaneous excitation of frequency components evident in these recordings is a characteristic of all known and putative recordings of Ivory-billed Woodpecker vocalizations. Published sonograms of the Blue Jay bell call [14] do not have this property.


Figure S2. Image from the 2006 video of a large woodpecker perched in the fork of a tree deep in the woods. The bird is to the upper right of the center of the image on the left branch of the fork.


Figure S3. The bird is perched on the right side of a branch in the 2006 video. The view is at an oblique angle in which the back of the bird is partially rotated away from the camera as illustrated in the artwork by Michael DiGiorgio. The volume of the crest and the rounded head shape are consistent with the Ivory-billed Woodpecker specimen but are not consistent with Pileated Woodpecker.


Figure S4. Since the 2006 video was obtained early on an overcast morning, field marks are not resolved in raw images of the bird silhouetted against the sky. After adjusting the brightness, a feature consistent with the left dorsal stripe is visible in the top left image. The similar feature to the left of the dorsal stripe feature is a broken branch as illustrated in the artwork by Michael DiGiorgio. It is clear from the image on the lower left (from about one second earlier in the video) that there is no vegetation in the position where the dorsal stripe feature appears when the bird moves into view. The crest appears to be raised in the image in the lower right as illustrated in the artwork. The exaggerated leaned-back posture of the bird is consistent with Ivory-billed Woodpecker.


Figure S5. The 2006 video was obtained while sitting in a kayak that was backed into the bank at a known position. Using a laser rangefinder that is accurate to within 0.5 m, the distance from the camera to the point where the bird was perched was determined to be 128 m. From a known distance, photos were obtained of casts of Ivory-billed Woodpecker and Pileated Woodpecker bills that were made from museum specimens (courtesy of Carl Perry). The comparison was obtained by scaling to account for distance. The Pileated Woodpecker cast appears to be smaller than the bill of the bird in the video. The Ivory-billed Woodpecker cast appears to be a good fit.


Figure S6. In order to estimate wingspan in the 2008 video, a 0.610 m reference object was held in the position of the bird during the approach and photographed from the same vantage point. The photo was scaled using the distance between two trees and other features in the scene. Since the reference object matches the span of the partially extended wings, it is clear that the span is significantly greater than 0.610 m when the wings are fully extended. The length of the reference object was chosen to be the wingspan of the Belted Kingfisher (Ceryle alcyon) in order to eliminate that species and other relatively small species from consideration.


Figure S7. Large white patches consistent with an Ivory-billed Woodpecker appear on the dorsal surfaces of the wings in three consecutive frames of the 2008 video, which are separated by 16.7 ms. The bird is flying toward the upper right, and only the white plumage is resolved against the dark mud in the background.


Figure S8. By comparing the reflection of the bird off the water (left image) with the dorsal view of the bird (right image) in the 2008 video, it is clear that the white plumage accounts for only a fraction of the surface area of the wings, which apparently have dark plumage that is unresolved against the dark mud in the background. As illustrated in the artwork by Michael DiGiorgio, the wings appear to be bent forward at the wrists.