This obs for example: https://www.inaturalist.org/observations/284956080
I agree with your remark about Observation Fields.
A photo of a sick leaf is an evidence for a parasite, and with sufficient knowledge it may be possible to ID the parasite (virus, bacteria, insect, ā¦). A dead animal is an evidence for a predator, but there is no clear evidence that this predator is a cat.
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In general - yes, dead prey could be considered evidence of the predator, but I think it can be complicated in practice to ID. Some predators are quite distinctive in how they kill/interact with prey, like shrikes. If there is only one species of shrike in an area, then a photo clearly of a shrike larder could be evidence of the shrike IDed to species level. I think Iāve seen other cached prey items IDed for the predator/cacher (large carnivores, woodpeckers maybe (though I havenāt seen these observations myself).
More tenuously - scat can be evidence of a predator. Scat is just prey before it has been digested. So thereās not anything preventing prey from being evidence of a predator, other than our ability to evaluate the information in the photo of the prey and how diagnostic it is.
On a side note, it strikes me that, assuming the predator moved the prey, an observation of the prey IDed for the predator is, in some ways, more accurate than one IDed for the prey. Itās pretty fair to assume that a predator left the prey somewhere it intended to (though of course a bird could drop a fish accidentally, etc.). But it seems much less likely that the prey intended to be in the location where the predator left itā¦
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i think an observed kill (or one that can be attributed to a predator) seems to qualify as an observation of the predator (in this case a cat). On the other hand observations of the prey (a dead bird), when attributed to the predator have the potential to mess with CV, so some more detailed guidelines from staff might be necessary for observations like this (in case they do not exist yet).
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I have once made an observation of the prey as evidence for the predator - and it is my only observation of a peregrine falcon: https://www.inaturalist.org/observations/19618094
-Oh, and of a tree chewed by a beaver https://www.inaturalist.org/observations/161141347. I think those observations are valid, I find it a bit strange for a cat, though.
The observer may have seen the cat, but an identifier cannot support the ID - from a picture of a bird, dead.
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The example that comes to mind is prey impaled on thorns and barbed wire by a shrike. My first awareness of shrikes, long before iNat existed, before I had ever held a digital camera, was walking along a path in Florida and there were multiple large crickets, and various other bits of animals, stuck on the barbed wire fence. It looked a bit like this observation: https://www.inaturalist.org/observations/253793668 but with several prey items over a 20m stretch. Someone explained to me that there must be a shrike that hunted there, and I was quite impressed, with no idea what a shrike was.
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I would say a dead animal can be evidence for the predator that killed it, in theory ā but usually we canāt tell. If the kill was witnessed and the observer explains that in a note, Iād certainly believe it! However, Iād have trouble confirming it. Hard to predict what Iād do.
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Compare this to a situation where someone posts a hopelessly distant and fuzzy photo of a bird and identifies it as a specific species, with a note that they saw it better in person. You can either ignore the observation, or ID it as āBirdsā, with a note that it canāt identified further based on the evidence shown.
In this case, the options seem to be the same: either ignore it and have it stuck in Needs ID forever, or ID it as Life, since the only thing we can tell from this photo is that something killed a bird. Maybe Iām being pedantic, but in the linked example itās not clear that the person that posted it actually saw a cat kill it.. All we know is that something killed it, maybe a virus, maybe another mammal, maybe something else.
Another question is if a pet cat killed the bird, should the observation be marked as ānot wildā?
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I partly disagree. If the bird is dead and the person IDās it for a cat because he saw the cat kill it, I think itās legitimate to leave the post at ācatā though I wouldnāt feel like it I could confirm it.
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It is legitimate to use observer notes as part of the evidence provided in addition to photo/audio media. IDers do this all the time ā i.e., information about habitat, or host plant, or smell, or a call heard but not recorded.
I imagine that people have different thresholds for how much written supplementary evidence they are comfortable accepting. A distant and fuzzy photo of a bird where the observer simply notes āsaw more clearly in the fieldā probably would not qualify. But what about if alongside that blurry photo the observer wrote a detailed description of what they saw (white head, forked tail, striped underside, teewit call, or whatever) and the photo shows enough detail to estimate size/behavior etc. for a species that is plausible for the location and distinctive enough that it is unlikely to be confused with anything else given the described features? I think some people (not everyone) probably would be willing to confirm such an ID.
If the observer described the act of predation and their identification of the predator is plausible, I donāt see how this is substantially different than a blurry bird photo, except that the media provided is indirect evidence of the organism rather than direct evidence of it. (Most people are capable of recognizing a house cat and distinguishing it from, say, a coyote, and the damage done by a cat quite likely looks different than damage by a virus or being hit by a car; if it is in an urban area, a house cat is a likely culprit, whereas if they identified the predator as a lynx or a weasel or something else unexpected, a higher burden of proof would apply.)
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This raises the question then, of what could be considered evidence?
If I see a bear carrying a stick, which it then drops, can I photograph the stick and tag it as a bear? I would instinctively say no, but why not? Whether the animal drops a bird or stick, all we have is the object that was dropped.
If I see a deer rub against a tree trunk as it passes, can I photograph the patch of trunk with no snow on it as evidence of the existence of a deer? If I see a bird take a mulberry from a tree, can I photograph the remaining stalk of the mulberry as evidence that the bird existed? Can I photograph grazed grass as evidence of a rhinoceros?
If I see duck take off from water, can I photograph the ripples as evidence of the duck?
If it is allowable to confirm ID on the basis of an image of an object that an animal allegedly interacted with, it would seem that effectively every animal that is observed can be raised to research grade by an image of something it interacted with.
To me there is a major difference between an image of a dead bird and an image of a track or a scat. Tracks and scats can be inherently diagnostic of the species, much like songs. Many people are provably able to identify animals to species level by looking at images of tracks and scats. I donāt believe that anyone could identify the predator that killed that bird just by looking at the image. It is no more evidence of the presence of the species than a mulberry stalk is evidence of the existence of a parrot.
Iām very suspect of the idea of allowing an observation to go to RG on the basis on someoneās assertion that they observed features that are not visible. We know that large numbers of people will confidently assert that they know the ID of a species, even arguing the point, when they demonstrably do not. It seems almost self-defeating to allow someone to confirm an ID on the basis that they have no verifiable evidence. Allowing an observation to be labelled as a thylacine precisely because of the lack of a clear photograph, when the same observation would be challenged if it was accompanied by a clear photograph seems nonsensical, as well as discouraging clear photographic evidence.
Once we are at the stage of simply accepting peopleās assertions as evidence of RG observations, the value of iNaturalist seems dubious.
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Itās certainly evidence but often not verifiable evidence, cat predation being a good example. I think everyoneās covered it wellā¦ I think there are limited cases where it could be useful to upload it as an observation, like characteristic predation such as shrikes or a stashed leopard kill, or combined with other signs like paw prints.
Besides the already mentioned examples, I would say that if we have any wildlife forensic scientists using iNat that would certainly be fascinating to see their work! Most of us donāt have the background to verify such observations, but tissue analysis, DNA and barcoding, bite mark analysis, etc. as well as studying the scene would be additional information that could be added to an observation. Itās used for wildlife crimes like poaching and to determine die offs from disease, but also for studying predated livestock to determine whether a rancher is entitled to compensation, conservation law, determining a predatorās abundance, and a great many other areas. Iād love to see that kind of observation here on iNat even if I couldnāt personally verify it, I think I could learn a lot.
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Dead bird in my garden.
We have cats.
But they pluck the feathers off first.
And they donāt āstash the residue in the ivyā.
But still my obs is - bird, dead.
Watching the Evidence of Organism votes on the original link.
1 yes (on what basis?) 2 no (including mine) = Casual
My issue is that sometimes even very skilled observers are mistaken, and describe an organism that doesnāt match the photos they provide. That happens often enough on observations with images that itās makes observer notes difficult to use, unless they are very detailed.
In this case, people often people assume that a dead bird they find was killed by a cat in the absence of any evidence to the contrary. Someone could have found a dead bird in their yard and just assumed a cat killed it.. In the linked example the observer eventually mentioned that they saw a cat kill it, which is much more helpful.
My understanding is that āEvidence of Organismā means ādoes this photo contain AN organismā, not ādoes it contain THE organism that itās identified asā. If thatās the case, than the answer to that question should be yes, but the ID could still be just āVertebratesā, if you donāt feel like the photo is evidence of a cat.
Sure. Iām not saying that people shouldnāt critically evaluate notes and assess whether the observerās account seems both plausible and reliable. I am not suggesting that just because an observer asserts something that this should be taken at face value, particularly if it is inconsistent with other evidence (photo/audio) provided by the observer.
But this doesnāt mean we should simply dismiss all notes out of hand. The significance of notes in supporting an ID will vary ā in some cases they may merely supplement evidence that already strongly points to a particular ID, in other cases they may provide key information that allows some other possibility to be excluded. It is a spectrum, and at the far end where the notes are doing most of the work, it is reasonable that users may decide that the notes are not sufficient (too much possibility that the observer mistook the organism or that there are other explanations for what they saw, or they personally are not comfortable assessing the reliability of the observerās account, etc.). iNat does not allow observations without any audiovisual evidence (media) to become research grade. However, drawings are accepted as evidence, and people regularly use contextual information not explicitly included in the media when making IDs, so it doesnāt seem reasonable to me to dismiss all supplementary notes on principle.
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I understand āEvidence of Organismā to refer, specifically, to the the ID we add. Cat? Track, scat, fur, bones? Predatory behaviour which is clearly cat?
Is there any life in this photo - applies to every obs on iNat. That would be a pointless DQA. Unless it is - no evidence of Life - please delete. That is the motivation for that DQA. From the iNat link -
- the observation doesnāt present evidence of an organism, e.g. images of water features, rocks, landscapes that donāt include the organism, etc.
I haz a confuz. I have been using this wrong?
I disagree. āEvidence of organismā is short for āEvidence of the organism for which the observation is posted.ā That evidence may be the organism itself or something else (track, fur, nest, etc.) but it is evidence of this particular species.
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Are distinct claw and tooth marks of an animal (on another animal or on the environment) not able to be used as identifiers?