Summary

Diagnostic traits in the Luneau video:

(1) The underwing pattern in flight consistently appears largely white, giving the appearance of having black wingtips but lacking any black along the rear, or trailing edge.

(2) The upperwing pattern in flight consistently shows a broad, white trailing edge, with no frames demonstrating the conspicuous dark rear border to be expected of normal Pileated Woodpeckers.

(3) The wings are longer relative to the body diameter than in Pileated Woodpecker and consistent with the wing shape of Ivory-billed Woodpecker.

(4) Reenactment of the scene using life-sized, realistically painted, dynamically flapping models produced images remarkably similar to those of the Luneau video using the Ivory-billed Woodpecker model, and images clearly identifiable as Pileated Woodpecker using a model of that species.

(5) The wingbeat frequency is 8.6 beats per second, which is almost identical to that recorded for Ivory-billed Woodpecker (as documented by one acoustic record from 1935). The wing-beat frequencies of Pileated Woodpecker are not known to exceed 7.5 beats per second, and more typically range between 3 and 6 beats per second.

(6) White plumage on the back is visible on the retreating bird as it begins to gain altitude. Ivory-billed Woodpecker has white on the back; Pileated Woodpecker has entirely black back.

(7) The dorsal view of the right wing as it begins to unfold shows a triangle of white that matches in size and position the white on the folded wing of an Ivory-billed Woodpecker beginning to launch into flight.

(8) The distance between the wrist area and the tip of the tail (32-36 cm, as measured when the bird begins to take flight) is comparable to known measurements of Ivory-billed Woodpecker and considerably larger than even the largest Pileated Woodpecker we measured.

(9) Only 20 seconds before the woodpecker flees, a bird with the size and color pattern of an Ivory-billed Woodpecker was perched within 3 m of the site from which the woodpecker took flight.

References

    1. Allen, Arthur A., P. P. Kellogg. 1937. “Recent observations on the Ivory-billed Woodpecker.” Auk 54: 164-184.
    2. Bent, A. C. 1939. Ivory-billed Woodpecker. Life Histories of North American Woodpeckers. Smithsonian Inst. National Museum Bulletin 174: 13-24, U.S. Govt. Printing Office.
    3. Charif, Russell A., K. A. Cortopassi, H. K. Figueroa, J. W. Fitzpatrick, K. M. Fristrup, M. Lammerink, M. D. Luneau, Jr., M. E. Powers, K. V. Rosenberg. 2005. “Notes and double knocks from Arkansas” (in Letters). Science 309: 1489.
    4. Christy, Bayard. “The Vanishing Ivory-bill.” Audubon. March-April 1943. Vol. 46, no. 2.
    5. Coues, E. Key to North American Birds. Fifth Edition. Dana Estes and Co., Boston.
    6. Eckelberry, Don R. 1961. “Search for the Rare Ivorybill.” Discovery: Great moments in the lives of outstanding naturalists. John K. Terres, ed. Philadelphia: Lippincott.
    7. Fitzpatrick, J. W., M. Lammertink, M. D. Luneau, Jr., T. W. Gallagher, B. R. Harrison, G. M. Sparling, K. V. Rosenberg, R. W. Rohrbaugh, E. C. H. Swarthout, P. H. Wrege, S. Barker Swarthout, M. S. Dantzker, R. A. Charif, T. R. Barksdale, J. V. Remsen, Jr., S. D. Simon, and D. Zollner. 2005. Ivory-billed Woodpecker (Campephilus principalis) persists in continental North America. Science 308:1460-1462.
    8. Gallagher, Tim. 2005. The Grail Bird. Boston: Houghton Mifflin.
    9. Jackson, J. A. 2002. Ivory-billed Woodpecker. No. 711 in Poole A, and Gill, F. The Birds of North America. The Birds of North Amercia Inc., Philadelphia.
    10. Jackson, Jerome A. 2004. In Search of the Ivory-billed Woodpecker. Washington, DC: Smithsonian Inst. Press.
    11. Peterson, R. T., and James Fisher, 1955. Wild America. Boston: Houghton Mifflin.
    12. Rosenberg, Kenneth V., R. W. Rohrbaugh, M. Lammertink. 2005. “An overview of Ivory-billed Woodpecker (Campephilus principalis) sightings in eastern Arkansas in 2004-2005.” North American Birds Vol. 59, no. 2.
    13. Sibley, D. A. 2000. The Sibley Guide to Birds. Knopf, New York.
    14. Sutton, G. M. 1935. Birds in the Wilderness. New York: MacMillan Company.
    15. Tanner, James T. “Three Years with the Ivory-billed Woodpecker, America’s Rarest Bird.” Audubon. January-February 1941. Vol. 43, no. 1.
    16. Tanner, James T. 1942. The Ivory-billed Woodpecker. Res. Rep. No. 1. New York: Natl. Audubon Society.
    17. Tobalske, B. W. 1996. Scaling of muscle composition, wing morphology, and intermittent flight behavior in woodpeckers. Auk 113:151-177.
    18. Winkler, H, D. A. Christie, and D. Nurney. 1995. Woodpeckers, a Guide to the Woodpeckers, Piculates and Wrynecks of the World. Pica Press, Mountfield, UK.