I photographed a Pelochrista kimballi, 1st NJ iNat record, on my moth sheet. A total of 4 photos taken 30 minutes apart. I thought they were 2 different individuals when I uploaded the photos and added the observations to iNaturalist. I was only able to identify to genus at the time. When another user identified observations to species, they asked if it was the same individual. Now I can’t be sure if it is 1 individual or 2. Photos are inconclusive to me but considering the rarity, it’s likely the same individual.
I am inclined to combine all 4 photos to one observation and make a note that there are possibly 2 separate individuals. Currently there are 2 observations noting that it may be the same individual with a link to both observations in the notes.
What is the preferred method in this situation? Observations linked below:
Welcome to the forum! It’s an interesting question. Since there’s reasonable doubt, I think both approaches are ok and you can just use your best judgment/personal preference. Adding a note/comment to the observation/s is probably the best thing to do whichever route you choose. Cool find!
For what an amateur’s two cents is worth, these two do look like different individuals. To my eyes it looks like there is more visible wear on the back of the moth encountered on an earlier timestamp. However I’ve never heard of this species before, and the varying angle and focus make it difficult to say for sure, so I’d defer to an expert’s advice if one appears.
This doesn’t actually answer your question but for this specific situation: I do think these might be two different individuals. The second link’s antennae are truncated, and the colors are also slightly different (eg. patches are darker, less prominent bar towards the back of the wings, bars on the feet are distanced slightly differently). While it might have been swiped by a predator in between your two encounters, and lighting might cause slight color variation, I’d non-expertly say they’re different.
Edit: Are your timestamps accurate? If so, you saw the cut-antennae one first, making it definitely not the same as the second full-antennae individual.
They look like 2 different individuals to me. And IMO it’s not as unlikely as it might seem to get two rare individuals on the same night - for one moth to be there, there must be a population of them nearby. I don’t think micromoths travel very far, so it’s unlikely to have strayed from far away. Congrats!
One of those moths has the antennae broken off, so definitely different individuals. When in doubt, make two observations. Accidentally posting the same moth twice isn’t really a problem, but accidentally lumping two individuals to one observation may present a problem if it turns out one of them was misidentified or something.
If I am not confident they are the same species I would make two observations of them. I do it like this when observing moths and more than once I was surprised.
While it’s true that many species stay close to their host plant, there are some species that travel far away. Probably the most extreme example is the Diamondback moth (Plutella xylostella), which is known to ‘ride the winds’ and migrate for thousands of miles within a few days. Not surprisingly, they occur all over the world.
I think your situation has already been addressed satisfactorily but I wanted to add that, after looking at tens of thousands of moth photos on iNat, there are numerous examples of people posting multiple observations of the same individual. There are numerous times a single moth is observed by multiple observers. As long as you are not abusive by posting multiple observations of the same individual when photos could better be combined, I think you can follow your own judgement and be well within the norm.
Looking at the time stamps of the two observations (about a 20 minute difference) and the low number of observations on iNats (about 30), my method would be to post them as two separate observations.
If the species was well represented on iNats, eg 1,000 of observations, I would consider a different approach.
I think the recommended solution would be to keep them as separate observations. As far as I know, iNat has no recommendation against posting multiple observations of the same individual at different times (in fact I think it’s encouraged if they were observed in two separate incidences), but it does have a guideline that an observation ideally only represents one individual.
Always be reminded that data accuracy is more important than a possible data guideline violation. You observed the individuals at different times over the evening, hence, it is possible these are two individuals (independent of the actual status that is discussed here). AND: Your observations carry not only geographic species’ records, but also metadata like time of activity for this species. So, a scientist looking for this may lose a point in time during which this species is active when you don’t upload the second obs.
Spatial/community ecologists like me always filter data over time and space (e.g. for niche modelling or diversity metrics) anyway and cater them to our needs. So from this point of view, no harm is done in general when you upload potential multiple observations of one species, but somebody else may lose data when you don’t.
I would also like to add that if you put that you are unsure then it is also fine. It can be hard to keep the moths separate. I know that I had a mothing night where I got 10 or 11 observations of a lesser observed moth. I can tell that nine of them are unique individuals but the last two observations may be the same moth almost an hour appart.
I count iNats- “one organism at one time” as adequate justification.
Also worth noting that there are probably a lot more individuals than one might expect on any given night. I’ve had experience with using a sheet blacklighting as well as trapping with “bucket traps” that collect all the moths that come in all night to be preserved as specimens. Species where I might think I see 1-5 per night on the sheet will often show up as 20+ specimens in the bucket trap. I suspect a lot of the moths leave the sheet and then others show up, and we generally assume it’s the same moth over and over again when it’s really a different individual every time. So if anything, we’re probably all being way too conservative in our estimate of whether we already photographed “that moth” earlier in the night.
Edited to add: I’m still waiting for the moth sheet “mark recapture” study to quantify how many moths are staying at the sheet, leaving, returning, etc. I know of one person that tried it, but marking things with scaly wings in a permanent way proved difficult.
It may or may not be the same individual but the observation thereof is by default different, even if it is already one minute later: different time, different angle, different lighting. Even if I was 100% sure it is the same individual, I would still not merge photos into one observation if there was a reasonable time of twenty minutes in between.
If you were to see that moth on, say, June 30th at 23:59h, submit it, and it is still present only two minutes later on the sheet at 00:01h of July 1st and you submit it again, you will have that species documented on two different days in two different months of the year, just because of how we categorize time in our system of months and days. You could even do this on purpose. Would that be cheating or providing misleading information? No, because it may be the same individual but then again the observation was different by default, and by adding an extra observation, you are adding extra information on the species to the database, in this case even adding a day and month of presence. If you were to merge the photos into one single 23:59h sighting, the database would lose information on the species’s presence in July. Furthermore, it can also be useful information to simply know that a moth stayed on the sheet for a certain period by having two observations of the same individual with some time in between.
I have heard of a rule that supposedly existed in the Netherlands in the past which encouraged mothers to submit all observations from 00.00h onwards to the day before if they started the mothing session on that day, in order to avoid ‘double counts’. Imagine how much information on the precise time acitivity of moths gets lost and distorted by such practice, especially for species that usually won’t even show up until 2-3 am.
