American Ornithologists’ Union Meeting

August 2005
View video footage of the talks.

The American Ornithologists’ Union meeting was held August 23-27 at the University of California, Santa Barbara. Ornithologists gave more than 400 presentations about ornithological research, including five talks about Ivory-billed Woodpeckers.

The scientific abstracts for the Ivory-billed Woodpecker presentations are below:


Status of recent acoustic search for Ivory-billed Woodpecker in the U.S.

CHARIF, R A; CORTOPASSI, K A; FRISTRUP, K M; FIGUEROA, H K; ROSENBERG, K V; FITZPATRICK, J W. Cornell Lab of Ornithology, 159 Sapsucker Woods. Rd., Ithaca, NY 14850.

As part of the 2004-2005 search for Ivory-billed Woodpecker (Campephilus principalis) in eastern Arkansas, we collected over 16,000 hours of acoustic data from over 140 sites in the Cache River and White River National Wildlife Refuges. Data were recorded by programmable digital audio recorders deployed for two to six weeks at each site. Audio files were initially screened using a spectrogram correlation based algorithm that detected sounds similar to templates of known ivory-bill vocalizations and double-knock display drums recorded from other Campephilus woodpeckers. Sounds selected by this automated process were further screened by human experts through spectrographic and aural examination. This process identified possible recordings of both ivory-bill "kent" notes and double-knock display drums from the study area during 2004-2005. In order to assess the likelihood that these unknown sounds were produced by an ivory-billed woodpecker, we compared them to known recordings of ivory-bills and other species that produce similar sounds. We did this using a combination of sound correlation, multivariate measurement, and multivariate classification methods. Here, we report on the acoustic survey process and on our ongoing acoustic analysis. In addition, we include analysis of a recording made by John V. Dennis in the Big Thicket of Texas in 1968, that may represent another recent valid report of a living Ivory-billed Woodpecker.


When standard techniques fall short—Novel and adapted survey methods for finding the Ivory-billed Woodpecker (Campephilus principalis) and other ultra rare species.

ROHRBAUGH, R.W; LAMMERTINK, M.; SWARTHOUT, E.C.H.; WREGE, P.H.; ROSENBERG, K.V.; BARKER SWARTHOUT, S.; AND FITZPATRICK, J.W. Cornell Lab of Ornithology, 159 Sapsucker Woods Rd., Ithaca, NY 14850.

From March 2004 through April 2005 we conducted intensive searches for the Ivory-billed Woodpecker in eastern Arkansas. The impetus for our search was a single confirmed sighting of the species; however, we had no information about numbers of individuals or the bird’s local ecology and behavior. Our 225,000-ha search zone consisted of dense, and often flooded, bottomland hardwood forest that was difficult to access and impossible to search systematically using typical avian survey methods. Our challenge was to find and document one or optimistically a pair of woodpeckers with only modest knowledge of the bird’s natural history. During more than 20,000 hours of searching we used a variety of techniques, including extended watches, cavity inventories, GPS enabled grid searching, autonomous recording units, audio playbacks, and decoys. Our techniques produced 5 robust sightings and 14 lesser encounters that merit scrutiny. We hope that experience gained during our search will inform and improve the efficacy of future searches for the ivory-bill and other ultra rare species such as Bachman’s Warbler.

Read an article  in BirdScope by Ron Rohrbaugh, “The Search for the Ivory-bill.”


Video evidence and sightings of Ivory-billed Woodpecker in eastern Arkansas in 2004-2005.

KENNETH V. ROSENBERG, JOHN W. FITZPATRICK, MARTJAN LAMMERTINK, and RONALD W. ROHRBAUGH, Cornell Lab of Ornithology, Ithaca NY 14850.

On April 25, 2004, David Luneau obtained a short videotape of a large black and white woodpecker fleeing from a water tupelo trunk in Cache River National Wildlife Refuge, Monroe Co., AR.  The following diagnostic traits constitute the first  evidence for existence of Ivory-billed Woodpecker (IBWO) in the United States in over 60 years: (1) a measurement of wing “wrist” to tip of tail made from the Luneau video (34-38 cm) is comparable with identical measurements taken from 1935 film of IBWO and measurements of IBWO specimens, but is larger than Pileated Woodpecker (PIWO); (2) pattern of extensive white and black on perched bird just prior to take-off and on the wings of the flying bird is consistent with IBWO and not PIWO. At least six well-documented visual encounters between 11 February 2004 and 14 February 2005 further support the existence of at least one male IBWO in that region during that period. One sighting involved two competent observers and two other sightings consisted of brief but careful studies through 10X binoculars. Extensive searching from December 2004 through April 2005 clarified that the sightings area is not a roost area or frequently visited part of a home range. No conclusive evidence for presence of IBWO was obtained in areas of seemingly suitable habitat in the adjacent White River National Wildlife Refuge. We believe the bird or birds range widely through this region and are unusually quiet resulting in very low detection rates. Searching will continue through 2005-2006.

Read the story behind the video.

Read the video analysis published in Science (subscription or article fee required).


What do we know about the effects of current management practices in the Mississippi Alluvial Valley on Ivory-billed Woodpeckers?

ROBERT J. COOPER, Warnell School. For. Res., Univ. Georgia, Athens, GA.

With the stunning rediscovery of the Ivory-billed Woodpecker in the White-Cache River system of east central Arkansas, questions immediately arise about conservation and management of a species about which we have no recent data. The dominant management paradigm of the National Wildlife Refuge (NWR) System is ecosystem management, in which natural ecological processes that maintain biodiversity are promoted, or mimicked. Two important processes in bottomland hardwood forests of the Mississippi Alluvial Valley (MAV) are gap-phase dynamics and flooding. In the White River NWF, forests are actively managed via timber harvest for a number of objectives pertaining to biodiversity, including the mimicking of natural disturbances such as wind or ice storms. IN one of the few long-term studies relevant to this scenario, flooding patterns rather than timber harvest influenced nest success of songbirds, likely by indirect effects on nest predator behavior. The major large-scale management activity in the MAV, reforestation to create large forest patches, should continue. It would seem prudent to at least temporarily halt timber harvesting on the Cache River and White River NWRs. Major water management projects currently proposed for the White River pose a threat to hydrologic patterns and must be halted. In the future, as we learn more about habitat affinities of the Ivory-billed Woodpecker, the possibility of using silvicultural options to achieve desired forest conditions should be seriously considered.



Rediscovery of the Ivory-billed Woodpecker and its conservation implications.

JOHN W. FITZPATRICK, Cornell Lab of Ornithology, Ithaca NY 14850