Advertisements

Trail Cam Photos Revisited

Frank recently found a series of images from our trail cam deployment discussed here. These photographs, taken with a second camera, are of very poor quality, but they show what is clearly a Pileated Woodpecker on the target snag. Frank’s discovery led us to re-examine some of the images discussed in Frank’s post and elsewhere on the site because they gave us a reference object to assess the size of the birds in two other low quality trail cam photos.

IMG_2735-1 IMG_2736 IMG_2737 IMG_2738 IMG_2739

Based on this reference object and informed by outside evaluations, we’re confident that the “mystery bird” discussed in this post is in fact a Red-headed Woodpecker. (We still concur with the author’s analysis of the other image discussed in the post.) The bird is clearly behind the tree but not very far from it, and it is simply too small to be anything else. Despite my initial interest in this photo, I had been leaning toward Red-headed based on feedback from a number of people and on the length of the tail.

IMG_7926

I have always thought that this was the most intriguing image in the series, although some reviewers have disagreed.

IMG_4195

I’ve also always believed that the bird was behind the snag and in front of the somewhat more distant small branches, which would mean it’s large. Frank, who has by now reviewed perhaps 1 million trail cam images, has always agreed with this interpretation.

Frank’s discovery of the Pileated sequence led me to re-examine this photograph and dig a little deeper. One reviewer suggested that motion blur made it impossible to make any judgments about size or distance from the camera. In response, I did a bit of research and found Focus Magic, a forensic program designed to reduce or eliminate motion blur.

The results of running the image (bird only) through Focus Magic are interesting. (No other processing was done.)

Image processed with Focus Magic. Setting for a 35 degree angle and a blur distance setting of 13 out of 20

Image processed with Focus Magic. Setting for a 35 degree angle and a blur distance setting of 13 out of 20. The object was selected using the lasso tool in Photoshop, making it possible to de-blur the moving bird without affecting the rest of the image.

I shared this processed image with Louis Shackleton, a professional photographer friend who has a background in ornithology. I also sent Louis one of the Pileated images and these two other trail cam photos that were taken within an hour and ten minutes of the first, on December 7, 2014.

IMG_4399

IMG_4313

The first of these shows what we believe to be either a Red-headed or an Ivory-billed Woodpecker in flight and behind the snag. The other shows an intriguingly shaped but badly blurred bird in flight, passing between the camera and the snag. (The motion blur in this image is so severe that I was unable to make any meaningful improvements using Focus Magic.) Louis had this to say about the photographs he reviewed:

“ . . .I concur that the first image is the most interesting. Comparing that and the image of the PIWO on the tree, it seems to be larger, [and] as you say, I think it’s beyond the snag. The second image, it’s also beyond the snag, but there’s no way to gauge how far. The third image, it’s definitely in front of the snag, but also no way to tell how far in front.”

Frank and I interpret the photograph as follows. It shows a long-necked, long-tailed, slender-bodied bird that is somewhat larger than a Pileated Woodpecker flying upwards at about a 35 degree angle. There is white on the trailing edge of the wing, although it’s unclear whether this white is on the underside of the left wing, the upper side of the right wing, or both. We do not believe this white to be an artifact, since it appears faintly in the unaltered image; it becomes more fully resolved when the blur is eliminated; it is still present even at a blur distance of 20, the highest Focus Magic setting, when image clarity breaks down significantly.

Focus Magic processed image with blur distance set at 5

Focus Magic processed image with blur distance set at 5

Focus Magic processed image with blur distance set to 20

Focus Magic processed image with blur distance set to 20

A couple of considerably more ambiguous features are also intriguing. The bird appears to have a fairly distinct and sizeable bill, and in the Focus Magic iteration in which the white is most clearly defined (blur distance 13), there’s a hint of red on the head, although this could easily be an artifact. While the William Rhein film of an Imperial Woodpecker in flight was shot at a different angle, we think the profile and structure of the IMWO in that footage strongly resemble our mystery bird.

Screen capture of Imperial Woodpecker in flight

Screen capture of Imperial Woodpecker in flight from the film by William Rhein

Screen cap of Imperial Woodpecker in flight, shortly after take-off, at a different angle, but with similar wing position.

Screen capture of Imperial Woodpecker in flight, shortly after take-off, at a different angle, but with similar wing position.

Edited to add: To facilitate comparing our mystery bird with the Imperial Woodpecker in the frame shown above, I’ve created a composite image using the 13-35 de-blurred image, which I’ve also brightened. In addition to flying downward, the Imperial is angled slightly away from the camera, foreshortening the neck and obscuring the bill.Composite

It has been observed that there’s nothing to prove our mystery bird is a woodpecker, and that’s a fair point; however, the size, shape, and apparent white on the back of the wing are all consistent with Ivory-billed Woodpecker. We realize that this is far from conclusive but can think of few alternative interpretations, all of which are problematic.

Advertisements

One Comment on “Trail Cam Photos Revisited”

  1. motiheal says:

    I think one obvious idea here is that woodpeckers like this tree!


Leave a Reply

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s