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Ivory-billed Woodpecker ( Campephilus principalis ) Persists in Continental North America.
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Ivory-billed Woodpecker (Campephilusprincipalis) Persists in Continental North America John W. Fitzpatrick, Martjan Lammertink, M. David Luneau Jr., Tim W. Gallagher, Bobby R. Harrison, Gene M. Sparling, Kenneth V. Rosenberg, Ronald W. Rohrbaugh, Elliott C. H. Swarthout, Peter H. Wrege, Sara Barker Swarthout, Marc S. Dantzker, Russell A. Charif, Timothy R. Barksdale, J. V. Remsen Jr., Scott D. Simon, and Douglas Zollner Science308, 1460 (2005)
Previous Studies Characteristics of the Ivory-billed Woodpecker (Jackson, 2002) Size: • Largest woodpecker in U.S. • 2nd largest in the world Vocalization: • Nasal-sounding “kent” • Unique “double knock” Feeding: • Prefers beetle larvae • Uses chisel-like beak to pry bark from dead trees
Previous Studies Populations of Ivory-billed Woodpeckers Habitat: • Lowland primary forests of southeastern U.S. (Jackson, 2002) • Populations widespread in area but not abundant in number • Documented only one pair per 16 km2 of forest (Tanner, 1942)
Previous Studies Populations of Ivory-billed Woodpeckers Decline: • Precipitous population decline began in late 1800s (Jackson, 2002) • Forests cut for wood products and cleared for agriculture • Estimated only 22-24 birds in U.S. by 1930s (Tanner, 1942)
Previous Studies Populations of Ivory-billed Woodpeckers Endangered: • 1930s last population located in NE Louisiana (Allen and Kellogg, 1937) • Detailed population study from 1937-1939 (Tanner, 1942) • Singer sold tract to lumber company - logging began 1938
Previous Studies “Extinction” of Ivory-billed Woodpeckers • Population in Singer Tract declined to 6 birds by 1939 (Tanner, 1942) • Last individual in Singer Tract seen in forest remnant in 1944 (Eckelberry, 1961) • Sporadic sightings reported, but no valid evidence until now Key Question Does recently acquired video and audio evidence provide conclusive documentation for the sighting of an Ivory-billed Woodpecker?
Materials Ivory-billed Woodpecker Sighted in “Big Woods” of Arkansas Evidence: • February 2004 - Feb 2005: Seven sightings, all within 3 km • April 2004: Luneau recorded video containing 4 seconds of activity – bird perched on a tree trunk, then flew • Although blurry video, crucial field marks allow identification of Ivory-billed woodpecker
Materials Pileated Woodpecker vs. Ivory-billed Woodpecker • Pileated common and abundant in Ivory-billed habitat • Ivory-billed identification must rule out Pileated possibility
Materials Pileated Woodpecker vs. Ivory-billed Woodpecker
Methods Video: • Examined Luneau video stills for markings on the bird in question • Examined numerous video clips of Pileated Woodpeckers in flight • Chose video frames with Pileated dorsal and/or ventral wing surface in view angles similar to Luneau video woodpecker views • Reduced resolution and added blur to Pileated frames until images were similarly out of focus as in Luneau video Sound: • acoustically monitored 20 km2 of forest near sightings
Results and Discussion Video stills analysis: • allows determination of size and wing pattern while perched • allows determination of wing pattern in flight Acoustic analysis: • “double-knock” drumming heard sporadically – gunshot echoes? • “kent” sounds recorded - exceptional Blue Jay calls?
Results and Discussion Perched Bird with inset interpretive drawing of Ivory-billed Woodpecker
Results and Discussion Bird in Flight - Ventral Wing Patterns with inset interpretive drawing of Ivory-billed (top) and Pileated (bottom) Woodpecker
Results and Discussion Bird in Flight - Dorsal Wing Patterns with inset interpretive drawing of Ivory-billed (top) and Pileated (bottom) Woodpecker
Conclusions • Although acoustic evidence is minimal, video analysis provides conclusive evidence for the sighting of an Ivory-billed Woodpecker • Results confirm the existence of at least one male of the species • Difficulty of detecting Ivory-billed woodpeckers in the Big Woods may be due to low population density • Big Woods - approximately 2000 km2 of potential habitat need protection based on evidence of possible Ivory-billed population • Future funding to continue searches depend on additional evidence
Bibliography Allen, A. A. and Kellogg, P. P. (1937) Recent Observations on the Ivory-billed Woodpecker, Auk, vol. 54, pp. 164-184 Eckelberry, D. (1961) in Discovery: Great Moments in the Lives of Outstanding Naturalists, J. K. Terres, ed., Philadelphia, pp. 195–207 Jackson, J. A. (2002) Ivory-billed Woodpecker (Campephilus principalis). The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Laboratory of Ornithology; Retrieved from The Birds of North American Online database: http://bna.birds.cornell.edu/BNA/account/Ivory-billed_Woodpecker/ Tanner, J.T. (1942) The Ivory-billed Woodpecker, Research Report No. 1, National Audubon Society, New York