Putative audio recordings of the Ivory-billed Woodpecker (Campephilus principalis) are presented along with discussions of the videos from which they were extracted and the observations that were made when these data were obtained. On two occasions, high-pitched calls were heard coming from the direction of a bird that was identified in the field as an Ivory-billed Woodpecker. These calls seem to match the description of an alarm call that was reported in the 1930s. One of the videos captured a series of the high-pitched calls, which sound similar to the Blue Jay (Cyanocitta cristata) bell call but do not match published sonograms of that call. A putative double knock, which is characteristic of the Ivory-billed Woodpecker, was captured in another video a little over a minute before a large bird with characteristics consistent with an Ivory-billed Woodpecker flew into view. Since it is extremely difficult to observe this critically endangered species, information on audio clues could have an impact on its conservation.

1.
J. A.
Jackson
,
In Search of the Ivory-billed Woodpecker
(
Smithsonian
,
Washington, D.C.
,
2004
),
322
p.
2.
J. T.
Tanner
,
The Ivory-Billed Woodpecker
(
National Audubon Society
,
New York
,
1942
),
111
p.
3.
J. W.
Fitzpatrick
,
M.
Lammertink
,
M. D.
Luneau
,
T. W.
Gallagher
,
B. R.
Harrison
,
G. M.
Sparling
,
K. V.
Rosenberg
,
R. W.
Rohrbaugh
,
E. C. H.
Swarthout
,
P. H.
Wredge
,
S. B.
Swarthout
,
M. S.
Dantzker
,
R. A.
Charif
,
T. R.
Barksdale
,
J. V.
Remsen
,
S. D.
Simon
, and
D.
Zollner
, “
Ivory-billed Woodpecker (Campephilus principalis) persists in continental North America
,”
Science
308
,
1460
1462
(
2005
).
4.
D. A.
Sibley
,
L. R.
Bevier
,
M. A.
Patten
, and
C. S.
Elphick
, “
Comment on Ivory-billed Woodpecker (Campephilus principalis) persists in Continental North America
,”
Science
311
,
1555
(
2006
).
5.
J. A.
Jackson
, “
Ivory-billed Woodpecker (Campephilus principalis): Hope and the interfaces of science, conservation, and politics
,”
Auk
123
,
1
15
(
2006
).
6.
G. E.
Hill
,
D. J.
Mennill
,
B. W.
Rolek
,
T. L.
Hicks
, and
K. A.
Swiston
, “
Evidence suggesting that Ivory-billed Woodpeckers (Campephilus principalis) exist in Florida
,”
Avian Conserv. Ecol.
1
, online (
2006
).
7.
M. K.
Steinberg
,
Stalking the Ghost Bird
(
Louisiana State University Press
,
Baton Rouge, LA
,
2008
),
173
p.
8.
See supplemental material Document No. https://www.scitation.org/doi/suppl/10.1121/1.3544370 for audio files, movie files, and images from the videos and other images that were used for comparisons and for estimating wingspan and flight speed. For more information see http://www.aip.org/pubservs/epaps.html. [supplementary material]
9.
B.
Christy
, “
The vanishing ivorybill
,”
Audubon
46
,
99
102
(
1943
).
10.
H. G.
Kramer
and
N. S.
Thompson
, “
Geographic variation in the bell calls of the Blue Jay (Cyanocitta cristata)
,”
Auk
96
,
423
425
(
1979
).
11.
D. R.
Eckleberry
, in
Discovery: Great Moments in the Lives of Outstanding Naturalists
, edited by
J. K.
Terres
, Search for the Rare IvoryBill. (
Lippincott
,
New York
,
1961
), pp.
195
207
.
12.
B. W.
Tobalske
, “
Scaling of muscle composition, wing morphology, and intermittent flight behavior in woodpeckers
,”
Auk
113
,
151
177
(
1996
).

Supplementary Material

You do not currently have access to this content.