High Detection Rate of Ivory-billed Woodpeckers in Congaree National Park, SC 2006 to 2009 Indicated Presence
copyright-Fred Virrazzi
There have been numerous reports of Ivory-billed Woodpeckers in South Carolina subsequent to the last accepted Singer Tract sighting (1944). The Palmetto State sightings were made by many excellent birders, rangers, hunters, naturalists, scientists and citizens.
In 2007, 2008, 2009 and 2011 National Biodiversity Parks, Inc. (NBP) researched, under various federal permits, attraction of Ivory-billed Woodpeckers during Point Surveys in South Carolina. Our field personnel had multiple Ivory-billed Woodpecker (IBWO, IB) detections in multiple years of the 4 field years in SC. These detections included a sighting, a kent, single knocks and double knocks reported by experienced personnel.
From 2006 to 2008 various additional formal surveys were performed by other entities and individuals under the umbrella of the South Carolina Ivory-billed Woodpecker Working Group (SCIBWWG).
Over the 4 subject years, 60 or more Ivory-billed reports came from the same ~ 26,000 acre park where NBP had multiple encounters during our research. There is latency for Ivory-billed reports going public due to various formal agreements; it can take many years for researchers to recognize that sightings were tempospatially related. The latency is partially by design.
For the first time, all the Ivory-billed, human detections that the author is aware of is summated in this draft table:
There were also several different IBWO detections by ARUs; these recorded kents and DKs. The ARO detections are not included in the above table but the SCIBWWG summary paper seemed to highly rate these as IBWOs or likely IBWOs.
There was an unprecedented number of Ivory-billed Woodpecker detections in this one, 26,000 acre park in SC from 2006 to 2009 rivaled only by the Singer Tract, LA after 1900.
This is an incredible number of human detections; no other area post 1944 has 67 detections claimed in any 4 year period. There is likely no single location in the last 75 years with 67 detections let alone 4 years.
For the first time, all the Ivory-billed, human detections that the author is aware of is summated in this draft table:
There were also several different IBWO detections by ARUs; these recorded kents and DKs. The ARO detections are not included in the above table but the SCIBWWG summary paper seemed to highly rate these as IBWOs or likely IBWOs.
There was an unprecedented number of Ivory-billed Woodpecker detections in this one, 26,000 acre park in SC from 2006 to 2009 rivaled only by the Singer Tract, LA after 1900.
This is an incredible number of human detections; no other area post 1944 has 67 detections claimed in any 4 year period. There is likely no single location in the last 75 years with 67 detections let alone 4 years.
At the Singer Tract, from 1941 to 1944 there were likely more than 67 detections claimed as the previously large forest area was attrited, one or more birds lingered and the last birds were somewhat acclimated to tract caretakers. The one, two or more birds there those 4 years were repeatedly seen over and over sweilling the detection number. Congaree (CNP) birds are comparatively harder to see in my experience yet there are many modern sightings. Without a full tempospatial analysis of these 67 detections it is impossible to say if more than one or two IBs could have been involved. The SCIBWWG was evidently disinterested in any mapping or statistical analysis of this unprecedented number of sightings.
Notes: All 3 detections were in an ~ 2 square mile area. A 2 square mile area is 1.41 mile by 1.41 mile; this is 1/20 of the 26,000 acre park.
Since all three detections were made in ~ the same 2 square mile area, the chance of correctly or randomly picking the area to agree with the prior sightings to better stage contrived detections would be 20 squared, = 400 to 1.
The three separate 2009 Ivory-billed Woodpecker detections that had no knowledge of each other's search location data are as follows:
Detection 1 2/7/2009 Fran Rametta, a NPS ranger along with Corinne Fenner, we’re leading a guided canoe tour.
Saturday February 7, 2009
1:30pm, sunny, 70 degrees
Corinne Fenner and Fran Rametta were leading a guided canoe tour and spotted a very large, chunky bird. It was dark colored and flitting from tree to tree after flying up from near ground level. As it was flying among tupelo trees, we saw a distinct line of white feathers along the back of both wings. There was a black line along the front of both wings. The bird was silent. This sighting lasted approximately 6 seconds. Please see attached map.
(exact author unknown to author but is not either sighters'). and
The details of the 67 Congaree detections are poorly described and exceedingly vague in the SCIBWWG's final report.
This summary work is done by committee, seems rushed and forced and lacks basic scientific information after mostly volunteers donated several thousand hours of assistance to the group and indirectly the government. Every sighting is only described as "brief" and some of those a "brief fly by". Brief is then never defined in the report. Two sighting may or may not be flybys; the paper is unclear. These 9 sightings demanded more granularity.
As Ivory-billed researchers and literature readers know skeptics have called the 10 minute long, very close Kulivan sighting of a pair of Ivory-bills "brief" (1999, Pearl River, LA). The sighting of a pair was for 10 minutes; this is not brief. Subsequently there were many sightings in that area with supporting video of an IBWO. Kulivan and his sighting were considered reputable; he was on the IBWO Recovery Team Committee.
Rarely has such an inadequate, casual treating of 9 sightings of an uncommon species let alone a species that is considered critically endangered been presented.
Here are the four sentences on the 9 sightings:
"In addition to acoustic encounters, a few visual encounters were reported from Congaree National Park, although all were brief views by single observers. These visual encounters did not provide enough diagnostic field marks to completely rule out other species. In Year 1, four observers reported 7 visual encounters, all of which were brief fly-bys. In Year 2 and 3, single brief visual encounters were reported."
Regardless there are other numerous data sets in the summary paper that strongly support the presence of IBWOs in Congaree if properly interpreted with plausible explanations.
For example, the final report's explanation of the acoustical detections of double knocks as possible duck wings striking, gunshots or Pileateds are implausible and unacceptable to this researcher. The IBWWG also considered some these skeptical explanations unlikely. More information from the past notes and present field (2022) is needed.
Also, it is unexplained how the report's authors determined there is "likely no breeding population" in Congaree with the 67 detections in Congaree but substantially less in other large open spaces of SC. "However, we believe it is unlikely that a population of Ivory-billed Woodpeckers persists in Congaree National Park due to the absence of firm results despite persistent search efforts for 3 years."
The results from SC indicate Ivory-billed presence. Repetition of IB detections in one location has often been denied by individuals and departments to have occurred, but serial Ivory-billed encounters has happened. Sightings, kents, double knocks and single knocks, collectively encounters, have been repeated in various SE USA locations besides the one described here.
In 2022 it again became obvious to a very few that two totally unconnected Ivory-billed search efforts had detected the species at least 3 times in the same localized section of the large park in 2009. A third party, a SC resident (G. DeBusk), hearing of the initial two person sighting report, including an avowed skeptic, hiked towards the sighting location. He viewed an Ivory-bill accompanied closely by a similar bird (probable IB pair) in the same exact area a week after the seminal event. He also found dead wood, insect working, immediate to the location of where the IBWO was first acquired. He considered the excavation highly indicative of Ivory-billed based on his past Congaree research.
In 2009 our team, during 7 days of wilderness camping and workman-like point surveying, heard a kent, a double knock and had an IB sighting. The sighting was punctuated with a subsequent double knock using the specially designed Point Survey method.
These three disparate parties had four IBWO detections with two not following or privy to each other's reports or locations; they were unaware of the others exact location within the park during the respective prior efforts. As mentioned another party, G. DeBusk, followed the fresh IB lead.
In science the more times independent experiments or studies are repeated with the same results, the more likely the conclusion is accurate. In statistics, replication is repetition of an experiment or observation in the same or similar conditions. Replication is important because it adds information about the reliability of the conclusions or identifications drawn from the field observations. The statistical methods that assess that reliability rely on replication.
The probability of the NBP detections being a purposefully attempt to mislead, assuming they occurred within the 2 mile square area that includes the seminal sighting can be examined by inferential statistics as follows:
As Ivory-billed researchers and literature readers know skeptics have called the 10 minute long, very close Kulivan sighting of a pair of Ivory-bills "brief" (1999, Pearl River, LA). The sighting of a pair was for 10 minutes; this is not brief. Subsequently there were many sightings in that area with supporting video of an IBWO. Kulivan and his sighting were considered reputable; he was on the IBWO Recovery Team Committee.
Rarely has such an inadequate, casual treating of 9 sightings of an uncommon species let alone a species that is considered critically endangered been presented.
Here are the four sentences on the 9 sightings:
"In addition to acoustic encounters, a few visual encounters were reported from Congaree National Park, although all were brief views by single observers. These visual encounters did not provide enough diagnostic field marks to completely rule out other species. In Year 1, four observers reported 7 visual encounters, all of which were brief fly-bys. In Year 2 and 3, single brief visual encounters were reported."
Regardless there are other numerous data sets in the summary paper that strongly support the presence of IBWOs in Congaree if properly interpreted with plausible explanations.
For example, the final report's explanation of the acoustical detections of double knocks as possible duck wings striking, gunshots or Pileateds are implausible and unacceptable to this researcher. The IBWWG also considered some these skeptical explanations unlikely. More information from the past notes and present field (2022) is needed.
Also, it is unexplained how the report's authors determined there is "likely no breeding population" in Congaree with the 67 detections in Congaree but substantially less in other large open spaces of SC. "However, we believe it is unlikely that a population of Ivory-billed Woodpeckers persists in Congaree National Park due to the absence of firm results despite persistent search efforts for 3 years."
Congaree has superior IBWO habitat to all those other areas.
Many ecologists use source-sink population models or equivalent to make conservation decisions. There is not a mention of which, if any, assumptions, methods, formulas, theories, models, etc. were utilized to clarify there is "likely no breeding population" in Congaree National Park.
Many ecologists use source-sink population models or equivalent to make conservation decisions. There is not a mention of which, if any, assumptions, methods, formulas, theories, models, etc. were utilized to clarify there is "likely no breeding population" in Congaree National Park.
Source–sink dynamics uses variation in habitat quality to hypothesis on population dynamics. NBP has ground assessed key IBWO habitat in three states. Congaree is superior to any remaining similar sized area in the SE USA. The COWASEE Basin (see following map) which includes Congaree NP also has some comparative carrying capacity to any similar ~ 200,000 acre area in the SE USA.
Ivory-bills are noted repeatedly in the literature as being very wary and quiet around their nests. There is no indication that the SCIBWWG designed its effort tempospatially to find nests or seriously research carrying capacity. There is no basis for the SCIBWWG to have concluded Ivory-bills are likely not breeding in the park; the evidence and source-sink dynamics actually strongly supports the possibility of breeding. Obviously more study is needed.
Ivory-bills are noted repeatedly in the literature as being very wary and quiet around their nests. There is no indication that the SCIBWWG designed its effort tempospatially to find nests or seriously research carrying capacity. There is no basis for the SCIBWWG to have concluded Ivory-bills are likely not breeding in the park; the evidence and source-sink dynamics actually strongly supports the possibility of breeding. Obviously more study is needed.
In 2009 our team, during 7 days of wilderness camping and workman-like point surveying, heard a kent, a double knock and had an IB sighting. The sighting was punctuated with a subsequent double knock using the specially designed Point Survey method.
In science the more times independent experiments or studies are repeated with the same results, the more likely the conclusion is accurate. In statistics, replication is repetition of an experiment or observation in the same or similar conditions. Replication is important because it adds information about the reliability of the conclusions or identifications drawn from the field observations. The statistical methods that assess that reliability rely on replication.
The probability of the NBP detections being a purposefully attempt to mislead, assuming they occurred within the 2 mile square area that includes the seminal sighting can be examined by inferential statistics as follows:
Notes: All 3 detections were in an ~ 2 square mile area. A 2 square mile area is 1.41 mile by 1.41 mile; this is 1/20 of the 26,000 acre park.
Since all three detections were made in ~ the same 2 square mile area, the chance of correctly or randomly picking the area to agree with the prior sightings to better stage contrived detections would be 20 squared, = 400 to 1.
The three separate 2009 Ivory-billed Woodpecker detections that had no knowledge of each other's search location data are as follows:
Detection 1 2/7/2009 Fran Rametta, a NPS ranger along with Corinne Fenner, we’re leading a guided canoe tour.
1:30pm, sunny, 70 degrees
Corinne Fenner and Fran Rametta were leading a guided canoe tour and spotted a very large, chunky bird. It was dark colored and flitting from tree to tree after flying up from near ground level. As it was flying among tupelo trees, we saw a distinct line of white feathers along the back of both wings. There was a black line along the front of both wings. The bird was silent. This sighting lasted approximately 6 seconds. Please see attached map.
(exact author unknown to author but is not either sighters'). and
"Fran was a jovial skeptic, so the change into an equally jovial believer was fun to witness." (Hunter, C. FB public comment 6/2022). Fran may be retired now (7/22, Virrazzi). Location - Cedar Creek
Detection 2 10/2009 NBP's permitted team had a three person detection within ~ 1 mile of Detection 1. A loud, agitated kent was heard by the entire team. (See official USFWS IBWO comment letter from E. DeVito below). Formal online reports were given to the required and correct jurisdiction; they are password protected with lead researcher access (Virrazzi). Immediate field notes were made and are as of 7/22 unpublished.
Detection 3 10/2009 A few days after Detection 2, NBP's team was hiking east to a survey point when the author saw a largely white-winged, dark bodied bird the size and shape of an Ivory-billed fly from the assumed base of tree surrounded by water. The bird was only ~ 150 feet away, eye level and no take-off disturbance rings were observed, meaning it was not sitting in the water before flushing. The park's ground is very rough and noisy; our team members are directed to space themselves 20 feet apart when we are hiking from survey point to survey point so researchers can better hear any ambient single knocks (SKs), DKs or IB kents. I was not able to get any team members on the bird or raise my binoculars because of the shortness of time in view and the high basal area in this late seral forest.
The team then did an unplanned, permitted ADK survey point at the spot starting several minutes later and had a response DK from a few hundred yards away within the post ADK designed survey waiting period (20 minutes), (see official USFWS IBWO comment letter from E. DeVito below). Formal, required computer reports were given to the correct jurisdiction; they are password protected with lead investigator access (Virrazzi). Immediate field notes were made and are unpublished as of 7/22.
Related Congaree NP Detections that have some details (there are many detections whose details are unknown to the public):
2007 - NBP an incredibly loud, Single Knock of an IBWO was heard ~ 2.5-3 miles S of Detection 1 in 2009 above.
2007 - Cornell University Mobile Ivory-billed Woodpecker Search Team effort. An Ivory-billed Woodpecker responded with a single double knock (DK) to a mobile team's anthropogenic double knock (ADK).
2008 - NBP Multiple single knocks were heard in an area within 1-1.5 miles of Detections 1-3
2/16/2009 George DeBusk, sighted a pair of Ivory-bills within 150 yards of the Detection 1 sighting location several days earlier; he was searching the park because of it. DeBusk is a highly regarded SC citizen with a formal zoology background. By the time of the sighting, he had been searching for the Ivory-billed in the park several times before.
Based on public information in the SCIBWWG's summary report and knowledge of NBP's and others' efforts, it is estimated that 10,000 total field hours were spent; this is one detection per every 149 field hours. In NBP's extensive experience in the field and reviewing modern literature and postings this is a high detection rate per time effort. NBP had an ~ 100% higher detection rate per field hour in Congaree than CLO efforts with different methods.
In NBP's studies this detection rate per hour for NBP is only exceeded at two other SE USA locations. At both those locations substantial evidence of IBWO presence was eventually made public by various researchers.
In general, the photographic possibilities for capturing an Ivory-bill in the Congaree are significantly reduced compared to most other areas because of the topographic conditions, lack of many canoe navigable waters in the forest, mostly wilderness conditions (few trails, noisy to move), superior canopy of 30 to 40 m, causing darkness, high DBH trees and basal area resulting in a dense mid and upperstory, and more.
Related Congaree NP Detections that have some details (there are many detections whose details are unknown to the public):
2007 - NBP an incredibly loud, Single Knock of an IBWO was heard ~ 2.5-3 miles S of Detection 1 in 2009 above.
2007 - Cornell University Mobile Ivory-billed Woodpecker Search Team effort. An Ivory-billed Woodpecker responded with a single double knock (DK) to a mobile team's anthropogenic double knock (ADK).
2008 - NBP Multiple single knocks were heard in an area within 1-1.5 miles of Detections 1-3
2/16/2009 George DeBusk, sighted a pair of Ivory-bills within 150 yards of the Detection 1 sighting location several days earlier; he was searching the park because of it. DeBusk is a highly regarded SC citizen with a formal zoology background. By the time of the sighting, he had been searching for the Ivory-billed in the park several times before.
Based on public information in the SCIBWWG's summary report and knowledge of NBP's and others' efforts, it is estimated that 10,000 total field hours were spent; this is one detection per every 149 field hours. In NBP's extensive experience in the field and reviewing modern literature and postings this is a high detection rate per time effort. NBP had an ~ 100% higher detection rate per field hour in Congaree than CLO efforts with different methods.
In NBP's studies this detection rate per hour for NBP is only exceeded at two other SE USA locations. At both those locations substantial evidence of IBWO presence was eventually made public by various researchers.
In general, the photographic possibilities for capturing an Ivory-bill in the Congaree are significantly reduced compared to most other areas because of the topographic conditions, lack of many canoe navigable waters in the forest, mostly wilderness conditions (few trails, noisy to move), superior canopy of 30 to 40 m, causing darkness, high DBH trees and basal area resulting in a dense mid and upperstory, and more.
Any careful Bayesian statistical analysis of Congaree's 67 IBWO detections will come up with a high probability of one or more IBWOs being present in Congaree from 2006 to 2009.
We recommend that the USFWS review the extensive evidence presented here and the original detection, sketches and recording in all the other federal and state govt. files before determing IBWO presence.
Regardless the evidence summated in this article, and NBP's USFWS presentation today does not support the extinction of the IBWO in SC.
Acknowledgements to E. DeVito, T. Haydu, L. Shaw, T. Thom, P. and J. Dubois and others for field survey assistance and support in SC.
Regardless the evidence summated in this article, and NBP's USFWS presentation today does not support the extinction of the IBWO in SC.
Acknowledgements to E. DeVito, T. Haydu, L. Shaw, T. Thom, P. and J. Dubois and others for field survey assistance and support in SC.
