Navigation Links
Dr. Michael Collins publishes paper on ivory-billed woodpecker
Date:4/28/2011

Dr. Michael Collins, Naval Research Laboratory scientist and bird watcher, has published an article titled "Putative audio recordings of the Ivory-billed Woodpecker (Campephilus principalis)" which appears in the March issue of the Journal of the Acoustical Society of America. The audio recordings were captured in two videos of birds with characteristics consistent with the Ivory-billed Woodpecker. This footage was obtained near the Pearl River in Louisiana, where there is a history of unconfirmed reports of this species. During five years of fieldwork, Collins had ten sightings and also heard the characteristic "kent" calls of this species on two occasions. Scientists working independently in three states have now published articles that report multiple sightings of and various forms of evidence for this elusive species, which is extremely difficult to observe and photograph due to its rarity, wariness, and tendency to roam over wide areas in remote swamp habitat. The two previous articles present findings from Arkansas [Fitzpatrick et al., Science (2005)] and Florida [Hill et al., Avian Conservation and Ecology (2006)].

During two encounters with an Ivory-billed Woodpecker, Collins heard high-pitched calls that seem to match the description of an alarm call that was reported by James Tanner in the 1930s but was never recorded. On both occasions, the calls came from the direction of the bird and began at a moment when the bird was alarmed. Several of these calls were captured in the first video, which received a positive assessment from an independent expert, Julie Zickefoose, whose paintings of Ivory-billed Woodpeckers have appeared on the covers of a leading ornithology journal and the leading contemporary text on this species. According to Zickefoose, the large woodpecker in the video has a large crest, large bill, long neck, and rared-back posture consistent with an Ivory-billed Woodepecker, and it has ponderous and heavy flaps and takes an unusual flapping leap that is unlike anything she has seen from a Pileated Woodpecker (the only other large woodpecker in Louisiana).

The second video shows a bird in flight with flaps that are radically different from the duck-like flaps that were expected, but a long overlooked clue in a photo from 1939 suggests that there had been a misconception about the flap style. The combination of the flap style and the size rule out all species native to Louisiana other than the two large woodpeckers, but several characteristics rule out Pileated Woodpecker. This footage was obtained when an Ivory-billed Woodpecker flew along the bayou below a tall tree that was used as an observation platform, providing a view from an advantageous perspective of the white stripes on the back and the white patches on the wings. A little over a minute before the bird flew into view, the video captured a putative double knock that matches a putative double knock that was recorded by Hill et al. in Florida.

Collins began searching for Ivory-billed Woodpeckers in November 2005, shortly after Hurricane Katrina passed through the Pearl River. His first sighting was on February 2, 2006, and then two weeks later he discovered a "hot zone" a short distance up the same bayou, where he had five sightings (two of exceptional quality) and also heard the characteristic "kent" calls of this species on two occasions (once coming simultaneously from two directions) during a five-day period. The first video was obtained in the "hot zone" on February 20, 2006.

During the summer of 2007, Collins started climbing tall cypress trees to watch for Ivory-billed Woodpeckers flying over the treetops in the distance. The idea was to increase the encounter rate by opening up a larger field of view. Professor Steve Sillett, of Humboldt State University, and his colleagues, Jim Spickler and Michael Taylor, donated their expertise and time as well as a full set of gear for climbing trees. The approach provided results less than a year later, but not as expected. On March 29, 2008, an Ivory-billed Woodpecker flew directly beneath one of the observation trees, and Collins saw the definitive white stripes on the back and white trailing edges of the dorsal surfaces of the wings. Just over a minute before the bird flew into view, the camera recorded a putative double knock that is consistent with a putative double knock that was recorded in Florida.

Based on historical accounts of a duck-like flight, the Ivory-billed Woodpecker was thought to have duck-like flaps in which the wings remain extended throughout the flap cycle. Although definitive fieldmarks were observed in the field, there seemed to be a contradiction when the video was inspected and found to reveal a flap style that is radically different from what was expected -- the wings are folded completely closed in the middle of each upstroke. This mystery was resolved by a long overlooked clue, a photo from 1939 of an Ivory-billed Woodpecker in flight with the wings folded closed. The observed flap style makes sense in hindsight since it is similar to that of other large woodpeckers.

The flyunder video provides the first putative footage of an Ivory-billed Woodpecker in cruising flight. Since the bird and its reflection from the still surface of a bayou are visible, it is possible to pin down the bird's position (which can't always be deduced from video footage) by triangulation. Since the bird was initially flying nearly directly toward the camera, it was possible to simultaneously extract from the video curves that define both components (horizontal and vertical) of the wingtip motion. Since the bird flew past reference objects, it was possible to estimate wingspan and obtain the first putative data on the flight speed of this species. The video also provides the first putative data on the flap rate. The combination of the wingspan and the flap style rule out all species native to Louisiana except the two large woodpeckers, and in fact an expert on the flight mechanics of woodpeckers, Professor Bret Tobalske, of the University of Montana, is "confident it is a large woodpecker." The Pileated Woodpecker is ruled out by the narrow wing shape, high flight speed, high flap rate, and large white patches on the wings, all of which are consistent with Ivory-billed Woodpecker. The video also shows a trace of white on the back/neck that is consistent with the dorsal stripes that were observed in the field.


'/>"/>

Contact: Donna McKinney
donna.mckinney@nrl.navy.mil
202-404-3322
Naval Research Laboratory
Source:Eurekalert  

Related biology news :

1. Michael S. Watson, Ph.D., receives Am College of Medical Genetics-ACMG Foundation Presidents Award
2. 2011 HFSP Nakasone Award for Michael Elowitz of Caltech
3. Michael Graetzel wins the Millennium Technology Prize
4. Adult Star Katie Michaels Attending NHL Game 7 Red Wings vs. Coyotes
5. Michael Betenbaugh wins 2010 Cell Culture Engineering award
6. American Society for Microbiology honors J. Michael Miller
7. Pacific Biometrics, Inc. Announces the Appointment of Michael Murphy, PhD as Chief Operating Officer
8. Annual Michael & Susan Dell lectureship in child health
9. AACR applauds nomination of Francis S. Collins, M.D., Ph.D., to be the new NIH director
10. ESHRE publishes English textbook for paramedics
11. Census of Marine Life publishes historic roll call of species in 25 key world areas
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Dr. Michael Collins publishes paper on ivory-billed woodpecker
(Date:2/2/2016)... , Feb. 2, 2016 Technology Enhancements Accelerate ... an analysis of the digital and computed radiography markets ... , and Indonesia (TIM). ... and market size, as well as regional market drivers ... and discusses market penetration and market attractiveness, both for ...
(Date:2/2/2016)... Feb. 2, 2016  Based on its recent ... Sullivan recognizes US-based Intelligent Retinal Imaging Systems (IRIS) ... Award for New Product Innovation. IRIS, a prominent ... North America , is poised to set ... diabetic retinopathy market. The IRIS technology presents superior ...
(Date:2/1/2016)... , Feb. 1, 2016  Today, the first day ... announced plans to develop a first of its kind ... of IBM Watson. In the first application of ... (NYSE: IBM ), and Welltok will create a ... assessments with cognitive analytics, delivered on Welltok,s health optimization ...
Breaking Biology News(10 mins):
(Date:2/11/2016)... ... February 11, 2016 , ... Reichert Technologies, ... continues today to pursue the highest level of accuracy and quality with the ... Refractometer and the AR5 Refractometer. Accurate, reliable and tough enough for the ...
(Date:2/10/2016)... /PRNewswire/ - BioAmber Inc. (NYSE: BIOA ), a ... Mitsui & Co. Ltd., its partner in the ... investing an additional CDN$25 million in the joint venture ... 30% to 40%.  Mitsui will also play a stronger ... Sarnia , providing dedicated resources alongside ...
(Date:2/10/2016)... Ky. , Feb. 10, 2016 NX ... utilizing its proprietary NeXosome® technology for early warning ... of its most recent study by Dr. ... at the Society for Maternal Fetal Medicine,s (SMFM) annual ... GA, February 1-6 th , 2016.  The presentation reported ...
(Date:2/10/2016)... 10, 2016  IsoRay, Inc. (NYSE MKT: ISR), a ... medical radioisotope applications for the treatment of prostate, brain, ... its financial results for the second quarter and six ... --> --> ... fiscal 2016, which ended December 31, 2015, a 12% ...
Breaking Biology Technology: