Day-to-day log during visits after 2013

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2-1-14. I have returned to the Pearl for a visit. It was nice to see the Tree 6 area again. After the original rigging of that tree was lost in a storm last year, I decided to transfer the line from the pulley to a carabiner that is attached to the strap that is down and to the right of the pulley. Last spring, I tried to do some maintenance on the trail to Tree 9, but it was blocked by a fallen tree and nearly a year of overgrowth. I managed to find parts of the trail and reroute it around the fallen tree. The rigging on Tree 9 still appears to be in good shape.

2-3-14. I did some exploring on the Mississippi side near Tree 7. There is good habitat in this secluded area, which is directly across the Pearl from where there have been sightings on the Louisiana side.

2-4-14. I spent a few hours in Tree 9 on a foggy morning. This tree is near the locations where there have been sightings, it is fairly easy to access, and it offers a good view in all directions. Some footage from Tree 9 is posted here.

2-6-14. Last year, I made two unsuccessful attempts to replace the rigging in Tree 8, which was lost in a storm. It takes a perfect shot with a bow and arrow to thread the needle and get a line up that tree. Each time I have gotten a line in place, there has been a problem with the end of the rope getting stuck in the fork. I wrapped the end of the rope with duct tape this time, and it passed through the fork. It was a wet and chilly day, and the rain and show started coming down while I was on the way up. Tree 8 is in a good location, and it provides a good view about 87 feet above the bayou.

3-28-14. I’m on the way back to the Pearl for another visit. Since the trail and tree maintenance was finished during the previous visit, there should be more time for stake-outs and searching during this visit. While viewing the discussion of the 2007 video on YouTube, someone noticed something interesting during the double knock event. There is a red glow about the head a few seconds before the double knock, when the bird is making the side-to-side motions. It also shows up several seconds earlier when the bird is climbing. This is apparently the first footage that has been obtained in recent decades in which the sex is resolved.

3-29-14. I left my house yesterday afternoon to begin another exciting journey to the Pearl River. After 1440 miles of driving, I arrived — right back at my house. I checked the water level in the Pearl before leaving, but a huge storm raised it up to flood level. I got all the way to Alabama before finding out about the flood, and then I did a U-turn. It has now been six years since my last sighting.

11-5-14. I have returned to the Pearl for a visit. I had a nice observation session in Tree 8, where I heard four double knocks around this time of year in 2009. It was windy, and the bird activity was low. Some footage from Tree 8 is posted here.

11-6-14. I spent some time in Tree 9, which provides a nice view over areas where Ivory-billed Woodpeckers have been observed. It was windy again, but there was more bird activity than the day before. There are some dead trees nearby where woodpeckers were foraging. Some footage from Tree 9 is posted here.

11-7-14. I began my work in the Pearl River exactly nine years ago. I have various aches and pains from the past few days. So I’m resting today. In the video footage that I posted from Tree 9, I mentioned a tree in the distance that could be Tree 8. Based on the bearing, apparent distance, and other clues, I’m now convinced that it must indeed be that tree.

11-8-14. I enjoyed a long observation session in Tree 5, which is located to the south of the area where I’ve had sightings. This tree provides an excellent view in all directions. The surrounding area is remote and has lots of tall cypresses that would seem to be good candidates for roosting and nesting. I had a few close calls with cottonmouths on the way back. Some footage from Tree 5 is posted here.

11-9-14. It’s a bit of an ordeal to carry climbing gear out to Tree 5. I will take a day to rest up. Just before getting to the top of Tree 5, I noticed that lichen was growing on the strap that holds the pulley in place. That made me feel a little uneasy, but then I noticed that the strap has significant damage after more than seven years of exposure to the elements. Since the rope was looped over a strong branch, I wouldn’t have fallen to my death, but it would have been an unsettling partial fall if the strap had snapped. The pulley makes it easy to pull the rope into place, but it increases the chances of the line getting caught up after big storms. I lost the riggings of Trees 0, 6, and 8 when moss and branches got snagged by the line and wouldn’t pass through the pulley. I now just run the line through a carabiner. It’s harder to pull the rope into place, but I haven’t lost any more riggings.

11-10-14. I kayaked up the bayou to the Tree 6 area. The weather continues to be nice, and woodpecker activity picked up.

11-11-14. I spent a few hours in Tree 6. During the flyunder in 2008, the bird flew just to the side of the tupelos in this photo. Some footage from Tree 6 is posted here.

11-12-14. I’m resting today, but I hope to get out to the swamp again before returning to Virginia. This photo shows Tree 5 from below. I’m visible in the crown in this photo, which gives an impression of the sturdiness of Tree 5. In the lingo of tree climbers, it contains several “bomber” branches near the top.

11-14-14. I spent a few hours in Tree 6 this morning before starting the drive back to Virginia. It was in the low 30s and windy and my feet were wet. I kept watch from a different branch, which provides a different view down the bayou. Bird activity was low. A woodcock flushed from the edge of the trail as I was walking back.

2-8-15. It was nice to be back in the Pearl River on a spring-like day with lots of woodpecker activity. I hiked along the bayou between the areas where the videos were obtained in 2006 and 2008. There have been signs of ivorybills in that area a few times over the years. I noticed that someone stole the rigging line from Tree 6. It took a lot of work to replace the line in that tree after it was lost in a storm. I won’t have time to do it again during this visit. I also went by Tree 8 and found that the rigging line appears to be intact.

2-9-15. I spent the morning to the northeast of the area that I visited yesterday. Once again, there was a good deal of woodpecker activity. It’s interesting to see the fluctuations in the numbers of certain species. During my first few years in the Pearl, I only saw a few Red-headed Woodpeckers. Then there was a huge influx and they were abundant for several years. Now they seem to be gone again. It seems that there are more Orange-crowned Warblers this year than in previous years.

2-10-15. All nine of my sightings in Louisiana were along about three miles of a winding bayou. I spent this morning looking for signs of ivorybills in areas between bends in the bayou. I visited Tree 9 and saw a rotten tree that looks like it could topple at any moment. I also took some photos of the nearly black mud near Tree 6. The white trailing edges on the dorsal surfaces of the wings are prominent in the 2008 video. Some of the black on the wings is also visible, but the dark mud in the background makes it harder to see than the white. I flushed an American Woodcock.

2-11-15. After enjoying a nice sunrise, I hiked out to Tree 9 and had a pleasant observation session up there. A sapsucker was looking down at me as I was pulling the rope into place. After climbing to the top, I noticed that it has been very active up there. I obtained footage of a Pileated Woodpecker in flight over the treetops in the distance (the movie plays at half speed). This was the type of event that I had in mind for ivorybills when I started using tall trees for observations, but the one in the 2008 video flew nearly directly below. The time has come to head back north.

7-21-15. I have returned to the Pearl for a brief visit. This morning, I visited the area near Tree 6. It was hot and humid, and there was little bird activity.

7-22-15. I climbed Tree 8 and enjoyed the view from 87 feet above the bayou. A Mississippi Kite was perched and calling nearby, but it flew away before I got the camera out. I encountered several cottonmouths while walking along the bayou. It would be nice to spend more time in the trees, but I need to head back north today.

2-2-16. On this date ten years ago, I had my first of ten Ivory-billed Woodpecker sightings. I was hoping to spend some time in the Pearl this winter, but those plans have been postponed due to flooding.

7-21-16. I have spent the past several days investigating the possibility of using a drone with a 4K camera for searching for Ivory-billed Woodpeckers. The approach seems very promising. Video footage from several test flights is available here.

8-31-16. I got my first high-definition video camera ten years ago. It was the Sony HDR-HC3. I wore out two of them during my work in the Pearl River. I just had a chance to try out a Sony FDR-AX53, which records in 4K. There have been some amazing developments during the past ten years. This camera has a better zoom and better stability. It also has a nice viewfinder — the quality is almost as if you’re looking through binoculars. If only I had that camera when I obtained the 2006 video. It was a standard camera, and I wasn’t able to spot the bird in the viewfinder. I tried unsuccessfully to spot it in binoculars. With this camera, I’m certain that I would have found the bird in the viewfinder immediately. Then I would have zoomed in and obtained footage comparable in quality to the film from the Singer Tract. Another advantage of this camera is that it records to an SD card that holds 256 gigs. The old cameras use DV tapes, which cause loss of time and battery power during rewinds, make lots of mechanical noise (especially after lots of use), and require playback to get the data onto a computer.

1-18-17. I have returned to the Pearl in order to get some drone footage of the swamp in the winter.

1-20-17. I launched the drone from a boat for the first time. The combination of a motorboat and a drone makes it possible to cover a large portion of a river basin that would have seemed unimaginable ten years ago.

1-24-17. A paper on video evidence for the persistence of the Ivory-billed Woodpecker was published today in Heliyon. This paper contains an analysis of several events that appear in the 2007 video and extensions of the analysis of the 2006 and 2008 videos that was published in a previous paper. It also contains an analysis that suggests that the expected waiting time for obtaining a clear image of an Ivory-billed Woodpecker is millions of times greater than it would be for a more typical species of comparable rarity. I did a drone flight up English Bayou while following along in a motorboat.

2-7-17. I have returned to the Pearl for a brief visit. I spent the morning exploring areas further to the north near Henleyfield, Mississippi, but the weather wasn’t suitable for flying the drone.

2-8-17. I flew the drone at the Old River WMA. I tried to find a trail that I used about ten years ago to access the swamp. I found what appeared to be the old trailhead, but the trail must have grown over.

2-12-17. I flew the drone again at Old River WMA.

5-7-17. I started having persistent back pain after doing some heavy lifting during a sea trip in the fall. Two months ago, it developed into sciatica after I crawled under a sink in an awkward position to replace a bathroom faucet. I could barely get out of bed for a few weeks. Severe pain in my left leg made it nearly impossible to sleep. After the first month of rehab, it seemed a great triumph just to be able to walk a few blocks from home. It will be a while before I’m able to hike in the swamp and carry a backpack loaded with gear.

10-2-17. A paper that discusses the double knocks of the Ivory-billed Woodpecker was published today in Scientific Reports. The concept of a harmonic oscillator is used to explain how the double and multiple knocks of Campephilus woodpeckers are related to the periodic drumming that is typical of other woodpeckers. This work was motivated by the fact that the woodpecker in the 2007 video appears to produce a double knock with only one thrust of the body. The idea materialized while studying footage of a drumming Pileated Woodpecker. After the body stopped thrusting, there were a few additional impacts by the bill. This led to the hypothesis that both types of signaling can be modeled in terms of a harmonic oscillator but with different types of forcing, which is periodic for drumming but impulsive for double and multiple knocks. When the forcing for drumming ends, the last few impacts are related to a double or multiple knock. The hypothesis was confirmed from a video of a Pale-billed Woodpecker that produces a double knock with only one thrust of the body (this footage may be viewed in the supplementary material). Video footage of a Magellanic Woodpecker producing a double knock with only one thrust of the body appears in Part 6 of The Life of Birds by David Attenborough.

3-3-18. I now have the capability of sending a drone out on search missions. During some recent tests, I found that large woodpeckers are identifiable in 4K video obtained from a cruising altitude of 40 meters, which is high enough to avoid collisions. Video footage from some of the tests is available here. I have acquired a drone that has a better camera and will be testing it soon.

3-11-18. A paper that discusses the possibility of using a drone to search for the Ivory-billed Woodpecker and inspect habitats was published today in MDPI Drones.

11-1-18. Having sciatica last year led to the discovery of two potentially deadly health problems. An MRI of the back revealed calcification in the prostate, which isn’t necessarily serious. This motivated me to get a PSA test, which came back borderline. A year later, the PSA suddenly increased by a large amount, and a biopsy confirmed an early stage of cancer. A scan to make sure it hadn’t spread revealed pulmonary embolisms. On this date, I had robotic surgery at Johns Hopkins. A follow-up scan revealed that blood thinners had dissolved the embolisms.

2-10-19. After starting to regain my strength after the surgery, I decided to spend some time in the Pearl River this month. I did a drone flight more than two miles up English Bayou, beginning at the mouth on the East Pearl River, passing over the locations where I observed Ivory-billed Woodpeckers in 2006, and ending at the site where the flyunder video was obtained during my final sighting in 2008.

7-2-19. A paper that covers several aspects of my work on the Ivory-billed Woodpecker was published today in Statistics and Public Policy. That journal was the perfect place for discussions of the analysis of video evidence in terms of statistics and probability and why the requirement for a particular type of evidence has been a failed conservation policy for several decades. The paper has an extended presentation of an analysis (that was originally presented in a 2017 paper) of the expected waiting time for obtaining a clear photo (the amount of time it would be expected to take on average to obtain such evidence) relative to the time it would take for a species of comparable rarity that has more typical behaviors and habitat. The paper also has a section on a long history of folly and politics that has undermined the conservation of the Ivory-billed Woodpecker, including incidents decades ago (that were apparently not discovered until recently) and comments by anonymous reviewers that help to reveal the depth of the folly and politics.

3-9-20. Video footage obtained during three encounters with Ivory-billed Woodpeckers was published today in raw digital form at a data archive along with metadata (extracted by a curator at the archive) that confirms that the digital video is genuine and when it was obtained. This archive might be useful to anyone who wishes to reproduce or extend my analysis of the videos. One of the advantages of putting the raw data out there is to debunk nonsense, such as a claim by a reviewer of a submission to the Proceedings of the National Academy of Sciences. As discussed in the Appendix of this paper, the reviewer suggested that the speed of the 2008 video was fraudulently modified in order to increase the apparent flap rate and flight speed by a factor of two. A prominent ornithologist (who specializes in woodpecker flight mechanics) analyzed that video and concluded from the wing motion that it shows a large woodpecker in flight. Only two large woodpeckers occur north of the Rio Grande in North America. The flap rate of the bird in the video is about ten standard deviations greater than the mean flap rate of the Pileated Woodpecker (the flap rate statistics of that fairly common species are known), which rules out that species and leaves only one possibility (the flight speed and other characteristics are also inconsistent with Pileated Woodpecker). By resorting to a suggestion of fraud, the reviewer essentially conceded that the Ivory-billed Woodpecker is the only plausible explanation for the bird in the video. One of the many unusual incidents that have occurred since the announcement of the rediscovery of the Ivory-billed Woodpecker in 2005 is that the editor allowed the comment to stand. It seems that the right thing to do (in the interest of getting at the truth) would have been to inspect the raw digital video, from which it is easy to confirm that the video has not been modified.

6-30-20. In the middle of the COVID-19 pandemic, I drove to Louisiana to do some kayaking and drone flights in the Pearl. In order to minimize the risk of exposure, I stayed in a hotel room in Slidell that has direct access to the outside, which made it possible to bring the kayak indoors at night. There probably isn’t much chance of a sighting at this time of year, but the beauty of the Pearl peaks in late June. I obtained this video while kayaking up English Bayou.

7-1-20. I wrapped up the visit by doing a few drone flights over hardwood habitats several miles to the north of the areas where I had sightings in the Pearl.

9-3-20. A paper about my work on the Ivory-billed Woodpecker was published today in Scientific Reports. This paper discusses the possibility of using image processing techniques to extract information from the videos. Not being an expert in image processing, I was limited in my exploration of this approach to using applications to vary quantities such as color, brightness, and contrast. The videos are available in raw digital form at a data archive to experts in image processing, who could potentially extract additional information with advanced techniques.

3-7-21. I arrived at the Pearl for a visit on my 63rd birthday.

3-8-21. I launched a drone from the site where the 2006 video was obtained in order to confirm the location. There had been claims that the video shows a Campephilus woodpecker that was filmed in the tropics. Although it’s easy to debunk the claim merely by noting that the leaves were down (this happens during the winter in Louisiana but not in the tropics), it was worthwhile to confirm the location. The drone was launched from near the location where I was sitting in a kayak while obtaining the video in 2006. Trees that are still identifiable appear in the first part of the drone footage, which shows landmarks such as the bends in English Bayou and the East Pearl River as well as the rocket towers and canal at Stennis Space Center. I used a DJI Osmo+ to obtain a stable video footage of the boat ride up English Bayou, starting at its mouth on the East Pearl to the location where I had five sightings during a five day period in February 2006. The Osmo+ is made by the same company that makes Phantom drones, and it has similar stabilization capability that is based on a gimbal. Note that trees in the distance don’t appear to move up and down in the video.

3-9-21. During the years when I was having sightings in the Pearl, I usually remained in the kayak (especially near the most sensitive areas) in order to avoid driving the birds away. Another motive for that approach was that it was difficult to hike through the aftermath of Katrina. On this day, I finally did my first hike between the locations where the 2006 and 2008 videos were obtained. I was surprised at how easy it was to walk through the forest now that the trees that fell during Katrina are mostly gone. I started the hike at the site of the 2008 video. Not long after beginning the return from the site of the 2006 video, I heard the best double knock I have ever heard in the field. I don’t put much stock in isolated double knock sounds, but I will have to try to spend some time in that area.

3-11-21. I did the hike between the 2006 and 2008 video sites again.

3-13-21. I launched a drone from the site where the 2008 video was obtained. This footage shows the observation position near the top of Tree 6, a view down the bayou of trees that are still identifiable, and surrounding landmarks from higher altitude. I did a few additional drone flights to inspect habitat and confirm that Tree 5 was still standing. I would like to do some observations from that tree, which provides an exceptional view out over the treetops of the hardwood zone where there were sightings and a large grove of cypresses that might be suitable for roosting or nesting. Now that the aftermath of Katrina is gone, it would be much easier to hike out to that tree for observation sessions than it was years ago. This footage illustrates what it was like to hike through parts of that area during the first few years after Katrina.

3-14-21. I wrapped up the visit with a few additional drone flights over hardwood habitats.

6-9-21. After months of flooding in the Pearl River, I finally had an opportunity to follow up on the double knock that I heard in March. I did some drone flights over the area. A dying tree appears in this image from one of the flights.

6-11-21. I hiked out to the dying tree, which is the most promising potential foraging site I have ever seen. It’s a massive tree with a huge trunk and appears to have only recently begun to die. If there is an Ivory-billed Woodpecker in the area, it will surely find this tree, which stands out among the healthy surrounding trees.

8-23-21. I did some drone flights over the Pearl River swamp. One of the flights was a repeat of a flight on 6-9-21 over a dying tree that appears in these photos. In June, there were brown leaves on top but green leaves on the rest of the tree. The entire tree was dead by August.

8-24-21. Gretchen Dawson and I took a boat ride to Tree 5, which we were hoping to climb. Due to obstruction along the bayou, we weren’t able to get closer than about 400 meters. We explored the possibility of dragging the climbing gear the rest of the way on a gear sled, but the area was partially flooded with lots of cypress knees that would have obstructed the gear sled. In the brutally hot weather, it would have been too late in the morning for climbing after struggling to get there. Before leaving the area, I launched the drone and obtained this image of Tree 5, which towers over the surrounding forest. We spent the rest of the morning visiting the dying tree. Due to surrounding vegetation, it is difficult to get good looks from the ground, but there were areas with large amounts of bark stripping. Since the area has been flooded much of the year, there were no strips of bark on the ground.

8-25-21. I dragged the gear sled down the trail along English Bayou to do some drone flights. In the high grass along the trail, I had two close calls with cottonmouths. During this visit to the Pearl, I have been trying different types of drone flights. One is to launch the drone up just high enough to get a good view out over the treetops. This is an alternative to climbing trees, but the drone only has a wide-angle zoom setting. After hovering for about 20 minutes, there is still plenty of battery power left to safely land the drone. The other approach is to fly up to about 100 meters and hover in place with the camera looking straight down. I obtained an audio recording while the drone was hovering at different altitudes and ranges.

8-26-21. I did some drone flights on the final morning of the visit. I obtained an image of a rainbow over the swamp during this flight. The video from this flight shows 16 years of post-Katrina regrowth in the areas between mature trees that survived Hurricane Katrina.

9-21-21. I did a few drone flights over the Pearl River swamp from the boat launch to the south of Stennis.

9-24-21. I did a few drone flights over areas that I had never previously covered from near Old Hwy 11.

2-20-22. On the 16th anniversary of the 2006 video, I hiked into that area. I saw and heard more Pileated Woodpeckers than I have ever seen and heard on any previous day in the Pearl River or anywhere else. This could be a sign of the continuing recovery of habitat since Katrina. I spent some time listening in an area where I heard a double knock last year. On the way back, I stepped on some unstable ground and sank nearly up to my hips. I had to crawl on my belly to get out of it. The last time I got stuck that bad, I tore the meniscus of one of my knees and ruined my cell phone. It appears that I may have slightly aggravated a problem with my lower back this time.

3-5-23. I have returned to the Pearl for a brief visit. I was in the area a few weeks ago, but the water was too high to do anything. I kayaked out to an area where I heard a double knock two years ago and deployed a Sony PCM-D100 audio recorder, which produces high-quality audio recordings. I rigged up an external battery so it will record for several days. As illustrated here, I installed it in a Pelican case with the microphones aimed downward in order to keep it dry. I took this photo of Tree 6, which Dalcio Dacol named Supernova Cypress. I had an interesting sighting in the general area where I had sightings of Ivory-billed Woodpeckers years ago. I saw and heard rapid wingbeats, dark plumage, and a flash of red on the head. I didn’t see any white. If it was an Ivory-billed Woodpecker, I could have missed the white due to the edge-on view of the wings. The video camera captured the wing sounds but no images.

3-6-23. I tried a few drone flights but with limited success due to a thick layer of fog. Although yesterday’s sighting wasn’t anything to get excited about, I decided to do the flights in the same area. I got the idea to fly the drone low over the treetops with the camera aimed backwards. The idea is to get footage of birds that flush just after the drone passes. I hope to get a chance to try this idea before heading back to Virginia.

3-7-23. I celebrated my 65th birthday by doing some drone flights. One of the ideas that I’m trying during this visit is to fly at high altitude (e.g., 120 meters) with the camera aimed directly downward. With this approach, the camera covers a relatively large area. It is difficult to identify birds from that high up, but it should be possible to recognize the white patches on the wings and rapid wingbeats of an Ivory-billed Woodpecker in flight from that angle.

3-8-23. Gretchen took me out in her boat to recover the audio recorder and do some drone flights (launched from the boat). I was relieved to see that the recorder was still running. I was pleased with the high quality of the audio recordings, some of which are posted along with drone flights that illustrate strategies for using a drone to search for Ivory-billed Woodpeckers (it’s best to view them with the 4K option and with the audio at full volume). The most basic approach is to skim over the treetops with the camera aimed ahead. There might be an advantage to aiming the camera behind in order to capture images of birds that begin to flush as the drone passes over. Flying high high above the treetops has the advantage that a larger area is covered and the disadvantage that birds are harder to identify. By flying at an altitude of 120 meters, it should be possible to blanket an area with repeated flights without disturbing the birds. With the camera aimed downward, it should be possible to identify an Ivory-billed Woodpecker in flight even from that high up.

3-9-23. On a sunny morning, I did some additional drone flights. During this visit, I had an interesting sighting and recorded an apparent double knock. If these were convincing, I would remain in the area. I will return to Virginia for now. Later on, I will return to the Pearl to deploy the audio recorder with an additional battery that will allow a week of continuous recording.

3-26-23. I deployed the audio recorder a short distance from the site where it was previously deployed. This time, it has two external batteries that should be sufficient for a week. With the microphones (which are inside the furry wind guard) sticking out the bottom of the Pelican case, everything stays dry, even during heavy storms like this one, which lasted for over four hours. I always love to see the azaleas in bloom along the bayou.

3-27-23. I did four drone flights between rain showers. During this visit, I’m focusing on the approach of flying the drone along a path of several kilometers, at an altitude of 120 meters, and with the camera aimed downward.

3-28-23. I was again limited by weather, but I managed to get in four drone flights.

3-29-23. I did five drone flights on the fifteenth anniversary of my tenth and final sighting. One of the videos contains an interesting event involving three birds in flight. There appears to be a lot of white on the wings, and the body appears to be black, but there is no sign of black on the leading edges of the wings. I think these birds are ducks.

3-30-23. I did five drone flights and captured an event involving two birds in fight along the same path as the bird in the flyunder video. They’re not Ivory-billed Woodpeckers, but the strategy I’ve been using during this visit has proved to be more effective at capturing birds in flight than the strategy of skimming over the treetops.

3-31-23. On the final day of the visit, I did five drone flights and captured a nice sunrise over the swamp. My final task of the day was to recover the audio recorder. I was pleased to see that it was still recording.