January 9, 2023

How to take photos of tracks for iNaturalist

In the video link included below, I demonstrate how to take photos of tracks that have a chance of confirmed ID by experts.

https://www.youtube.com/watch?v=L9wlgyiStO0

I have expanded on this in the following post.

1) Scale, scale, scale! Always include some reference of scale. Most track and scat images are useless without a scale reference. Sometimes there is something in the image, a cone scale or a leaf, that the expert can use to help them understand the size of the tracks, but usually, a track or scat image without a reference of scale can't be conclusively identified to species. Some people use their hand for scale. This is useful for larger species, where the difference of few cm won't matter too much, but without knowing the length of your hand or the width of your thumb nail to the nearest mm, your hand as scale for smaller tracks is not ideal. Furthermore, people often include their hand as a scale reference without placing it on the surface at the same level as the track. The scale needs to be the same distance from the camera as the track. If you are serious about tracking, and submitting identifiable track observations to iNaturalist, you should cary a ruler to place by your track observations for taking photos. If you forget your ruler, then the next best thing is any flat object with a recognisable and consistent size. A coin works very well for smaller tracks. No coin? then include a personal item in the photo for scale, like your sunglasses or chapstick, then when you submit your observations to iNaturalist, include the dimensions of the object used for scale (not all chapsticks or sunglasses are the same size).

2) Take a full Frame picture. Hold the camera directly above the track, not at an angle, and fill as much of the frame as you can with the track, to capture as much detail as possible. Try to eliminate shadow, which might look nice in the picture, but obscures details that might be important. I try to put the sun at my back, to shade the track, and eliminate any shadow. Sometimes I get a friend to stand in a position that strategically blocks the sun to help with this. The same applies to scats.

3) Document multiple examples. Take more than one picture of different tracks from the same animal following the technique in 2). This is important to document consistency in the features of the track. It's also important to help reduce observer bias -- this happens when the observer takes only a picture of the one footprint that looks most like it is from the species they hope the track belongs to, and ignore all the footprints with contrary evidence.

4) Multiple Tracks in one photo. Take a picture from further away that captures the track pattern, this picture should include at least 4 footprints. Scale is important here too. Ideally you would lay a tape-measure down along the footprints in this photo. You might also improvise with a ski pole or trekking pole, or report the space between footprints in the comments. This photo is important because animals have more than one foot, and front feet usually have different features than hind feet. Sometimes a front foot is more helpful for identification than a hind, and vice versa.

5) Track or trail pattern. If possible, take a photo that captures more of the track pattern that includes many (more than 4) footprints. This photo will have to be at an angle, and you don't necessarily have to include scale in it, though you can, and it might be useful. Emphasis of this photo is on the general pattern of multiple tracks, not on any individual track. This photo is important because different species have different ways of moving, and different ways of moving result in different patterns of footprints.

6) Context and habitat. Take a photo where the emphasis is on the context and habitat and not the track or scat. Try to include the subject tracks or scat in the photo if you can, but the important thing is to convey some essence of the habitat and circumstance in which the tracks or scat occurred. Habitat and context are similar, but not the same. Habitat is mostly about vegetation, what kind, and what density. Context is more about the features on the landscape that the tracks or scat might be associated with; a road, an intersection of two trails, the edge of a clearing, proximity to water, following a rabbit trail, etc.

7) More is better. Don't just submit one photo of a track or scat if you hope for an expert to be able to help you confirm identity. iNaturalist allows you to submit 4 photos at a time, so as a minimum, submit at least 4 photos. One of the footprint, one of another footprint, one of the track pattern, and one of the context.

8) Don't stop at 4 photos. iNaturalist only allows 4 photos to be uploaded at a time, but it allows you to make multiple uploads to a single observation, so there is no need to stop at 4. If the subject of your photos is something you think may be significant or interesting, or new to your life list, then stack the deck towards getting a solid id from an expert by providing as much information as possible, including LOTS of photos.

Looking forward to comments.

Posted on January 9, 2023 10:36 PM by josephlitke josephlitke | 1 observation | 2 comments | Leave a comment

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