When registering observations, I often rely on the GPS location from my camera, and my memory of where i was when the image was taken.
For observations of plants and insects, the GPS location and the location of the observed object are close to identical. But for birds and larger animals, the location of the observer and the observed object can differ, sometimes a lot.
What to do here? Use the gps location of the observer? This is the easy way, as we often get this automatically, and it is included in the uploaded information from the image or the mobile device when adding observations. Or should we use the location of the object, deducted by the observer position, and the angle and estimated distance to the object?
ideally, you would note what your coordinates + accuracy represent in your observation description (and elaborate on those, as needed, with angle and elevation, etc.), but short of that, i think you should just do whatever you prefer to do, consistently, and in the most accurate way possible.
You are marking the point of the organism, so you should mark the point of the observed. Of course, as you point out, most of the time they are close enough that it doesnât warrant the time and effort of âamendingâ the camera GPS point to an estimate of that of its subject, but ideally you want to be marking the location as close to the organism as possible. Itâs of no real scientific interest where you were standing when you saw it. Indeed, imagine you were in a helicopter and flew in a huge circle around a polar bear, taking photos with a powerful telephoto lens â your observation would have multiple observer GPS points perhaps separated by kilometres. But itâs the polar bear that is your data point and thus its position that (in an ideal world) your observation should record.
If we take this to an extreme (for the purposes of a thought experiment) and imagine you used some ultra-telephoto equipment to photograph a tree from very high up on a high-altitude balloon or the International Space Station or something⌠If you marked the location of that tree as the observer GPS point, people later searching for that species could get the impression that that species grows hundreds of kilometres outside its real distribution range. Of course, such an extreme case would rarely happen, but but even so such inaccuracies on a scale of hundreds of metres would be common and represent a lack of precision in the data.
Hence why I say âin an ideal worldâ. In any case, polar bears themselves range over such vast distances that the odd 1km of inaccuracy is neither here nor there for most purposes. But my point would have been the same if the subject was some very rare super-localised tree in the middle of the Okavango Delta, where it shouldnât be too hard to get enough landmarks to pinpoint the position precisely. Anyhow, iNat data is by its nature messy, and of course we have to accept that there are all kinds of inaccuracies (most people will generally leave the position as the camera geolocation point, which itself may be subject to errors due to poor signal etc) but still, wherever reasonable, we should strive to make our contributions to the data as accurate as we can.
This kind of stuff is always going to be on a case by case basis. I have photos from years ago taken on analogue cameras with no GPS, where I can only be certain of the location down to the precision of an entire national park, for example. Itâs still better to make this data available on iNat than not, even if I can only mark the place with a 10km or even 50km accuracy. As long as we use the accuracy circles properly to indicate that, then thatâs ok.
One of the few times this might make a difference is when the subject, such as a bird, is in one nation, state, or county and you the photographer are in another. Such as being on one bank of a river and shooting a bird on the other at some border. Biologically it makes no difference but for record keeping purposes it might be important to you.
Iâve encountered this when observing near county lines so Iâve learned to pay a bit more attention to where I place my markers. I donât have accurate GPS coordinates so I usually pick a spot on the map with an accuracy circle and sometimes have been surprised that this resulted in observations being recorded for the neighboring county and thus not showing up as expected in county searches. Also happens quite a bit with state boundaries between NC and TN along the Appalachian Trail. You can literally stand in TN and photograph a plant growing in NC and vice versa.
I have a project for doing this. I usually have the accuracy cover both territories but sometimes itâll show up as either side. Iâve never observed anything really substantially unique or exciting either, so I donât really worry about it making a difference. Itâs a neat phenomenon, though.
On eBird, I have a record of a bird in CĂ´te dâIvoire, a country where I have never been, not because my coordinates in Liberia were inaccurate, but because the country border that eBird uses is inaccurate.
My personal standards are as follows. I use all of them.
Best: The location is where the organism is, with a moderately small accuracy circle.
2nd best: The location is where I am but with a large enough accuracy to include both me and the organism Iâve photographed.
3rd best: The location is where I am and the accuracy circle probably doesnât include the organism but the organism could be seen from there, so (compared to the size of the whole world) thatâs good enough.
Agreed. Generally, if you can get a diagnosable photo of some organism and even if youâre using a telephoto lens to get it, your location and the subjectâs location are for practical purposes the same. I will still adjust the location circle a little to capture the actual location of the subject.
You should report the GIS boundary error to the eBird team. I had a similar issue with a different pair of countries, and they did eventually fix it. Took at least a couple of years â doesnât seem to be their top priority â but they do want to know about it. And if they donât know about it, they canât fix it.
Iâve done a few observations of specimens under the microscope, and for those, the discrepancy is even greater between observer/observation. I always make sure to note down and then mark the location where I collected them.
Marking the capture location is definitely the correct thing to do, but I think this is a slightly different situation. In this case, you did indeed make the initial observation when you captured the organism there, though you took photos later. Presumably you and the organism were in the same spot if you captured it (though I suppose someone could capture something with a drone or fishing net/line or something at different location from where they were).
I would prefer to record the observation with locality of the polar bear, even with low accuracy (marking a large circle on the map, and possibly making some mistake with judging the position of the bear), than to put the locality to the place where I was positioned, with very high accuracy but substantially far away from the bear itself :)
Iâm not convinced that the difference is that significant. Nobody will be able to use the âobserverâ or âobservedâ location to refind the same bird/animal except under exceptional circumstances like nesting. Does it matter that your observation circle crosses an international border? I say no. Does it matter that the polar bear was 500m away from you? No again.
I would argue that accuracy is more important in small-scale situations. If you are doing a Bioblitz in a small park with the intent of documenting invasive plants you want the best accuracy you can get. If you are documenting birds in the same park knowing the bird was merely in the park is probably good enough.
Since I geotag my photos based on a GPS track, I just use the position where I was when I took the photo. For most mobile organisms (eg birds) this doesnât make too big of a difference, and for plants Iâm almost always right next to the plant. Edge cases are when Iâm using a telephoto lens with a decently long minimum focus distance (3m) and am photographing a plant, or this observation where I moved the location to the other side of the river where the birds were actually nesting because I wanted to give a more accurate location for the nest.
Thatâs a good question. The problem occurs when I take a liverwort sample for microscopic examination. Pictures are taken at home, but the original plant lives somewhere in the forest. Sometimes it is hundreds of kilometers away.
In such a case, I mark original position of the plant, not of my microscope.
Thatâs the right way to do it. I like to take at least one picture of the organism in situ before collecting it for microscopy to have a picture to go with the actual location, and then add microscopy images etc. to the observation once I get it under a microscope. There are some observation fields and projects to make observations with microscope images more searchable that might help increase chances of someone knowledgeable looking at it and suggesting an ID.
