I think the piece that’s missing in this example is whether or not the situation is explained in the comments (especially with links to previous observations). If the new survey photos were added without any comments, it seems completely reasonable to question the identification.
It’s my take that every observation should stand on its own, and it shouldn’t be on the identifier to dig through other observations to find important context.
To be honest I barely ever explicitly disagree unless I think the id is probably wrong - looks wrong or way out of range and habitat. If someone says they saw white ash and has a photo where I can’t tell if it’s white ash or green ash, and both grow nearby/are in range, I leave it alone. Bumping it back bumps it to genus with a ton of other ash species and ruins the observation. Also sometimes new people come along who are especially good at those species. I understand doing it in the case of the aphids or maybe a really rare and difficult plant like a sedge you need a scope to identify that a middle school kid records in the playground and the photo is just a blurry blob. But I think mostly… better to leave them be. I do wish “no further Id possible” still worked on observations with only one ID though. (For instance some of my own where I was confident of ID but when I upload I see that the photo is insufficient for anyone to verify). But with plants if nothing else someone can usually go back and look for it later.
I would tend to only disagree if I can see evidence that it is not. If I thought it was 95% likely to be that species, can see no evidence that it is not, and that I know that there are two species similar, I might ID at species with a comment that I am not certain, stating in the comment the other taxa that it might be. If the observer responded that they couldn’t be sure either, then I would change my ID to genus non-explicit. I agree with Charlie, if it represented an out of range scenario then that would significantly change that 95% confidence, and I would probably hold that as enough reason to determine it not to be that species, and ID explicit disagreement.
There has been a lot of discussion around the explicit disagreements, and as best I can tell, we should only be doing so if we can see evidence that it is not that species/taxa, or if it is an absentee/unresponsive identifier and they are not responding to dialogue over the ID and the community [would] agree that an explicit disagreement to bump the ID back is appropriate. So on that basis, you should be initiating dialogue before making such an ID, or at least have been involved in such dialogues on past observations of that taxa/place such that you can confidently predict what the outcome of such a conversation would be in the current instance.
@fogartyf You recognized a detail that I purposefully left out–the need for subsequent comments to link observations together. We’re struggling with just such a case here in Austin, TX. A plant that was photographed, dissected, and documented (with diagnostic images) was subsequently photographed in a general way (by multiple parties) without linking comments. Now a very knowledgeable identifier is downgrading all subsequent observations to genus/tribe/family solely because he can’t ID the subsequent images, even after the previous documentation has been pointed out. In this case, the identifier is taking the concept that “observations must stand alone” to what is, IMHO, an unreasonable extreme. I want to be clear: The identifier is absolutely correct that the subsequent imagery/observations, by themselves, are not identifiable to species level. But this identifier is going back through and downgrading everything he can’t ID as stand-along observations. Just a bit frustrating.
This can happen now. It just requires an extra step. If someone answers “Based on the evidence, can the Community Taxon still be confirmed or improved?” with “No, it’s as good as it can be” then a genus level identification will become research grade. It still needs to meet the other criteria of research grade of course. It is documented but I’m not sure it’s well know.
Actually this isn’t correct. It just needs two IDs, they don’t need to both be at genus level. A family level ID + a genus level ID would do it for instance.
Back to the original post and question: the examples of western Neotamias chipmunks and Myotis bats are good ones in that they often cannot be IDed to species based on photos, unless the photos are close-ups of certain key characteristics, and that’s usually unlikely. A number of small mammals are like this and can be challenging to ID even with a preserved skin + skull/skeleton specimen.
I usually just add a comment to the record pointing out it could be Species A (the ID provided by the submitter) but based on location and what’s visible in the photo it could also be Species B or C, etc. Sometimes if there is information on habitat and elevation you can lean towards one species or another, but I tend to not provide an ID, just a comment. And I don’t downgrade the record to genus; I figure that’s up to the submitter to address.