I am involved in a project surveying syrphids (hover flies) in Maine. One of the objectives of this work is to get an idea of the flight period (when they are active). This is our first year. Today, after uploading images from yesterday (likely the last day of the season) it looks like I have added three observations of the same specimen, on October 24, then November 2 then November 15. Where the first and last observation dates are likely most useful, I hesitate to take those down. I’m looking for some guidance on how this might be handled, because I don’t want them being flagged as “duplicates”. For now, I have added notes on all three cross-referencing the other two observations. Here are some ideas:
Move all images to one observation, highlighting the different dates in a comment in the notes. The problem I anticipate for this is that when the admins sort the observations for flight periods, the first and last date for this specimen will be lost. On this one, the last date is likely key, so if I were to move them all to one observation, this would be my preference.
Leave them as they are now, but add a note that the “duplicate” observations are keyed to our need to define flight period for the species. In this case, I’d move (or remove) the November 2 images, as those are superfluous for the purpose of the survey.
I have read the other closed topics on duplicate images and this wrinkle doesn’t come up (or I can’t find it).
Observing the same specimen periodically can provide valuable information regarding changes or lack thereof over time, so yes, keep all the observations intact and link them.
I was going to err towards one, just speaking for myself because I have observations of the same monarch life stages over a period of days, if not minutes in the case of one emerging from a chrysalis……but you make a good point about data loss. I just feel weird with it possibly looking like spam when I have 15 or so shots of the emergence and wing hardening process for a monarch…… or, multiple shots of the same chrysalis over several days transitioning from green to clea.
Separating different life stages of the same individual is helpful from an annotation standpoint. When each life stage is its own observation, each can be annotated with the respective life stage. That makes it easier for other people to find and use, especially if they are only interested in one particular life stage.
I have seen observers upload several observations of the same individual, each just a few minutes apart, and no one objected. In my experience the objections to duplicates are usually when it is the exact same photo again.
A good general rule of thumb is one observation/individual/day unless something significant changes/there is a specific reason to make more (metamorphosis, change in behavior, death, etc.).
Same species, same time, same date, then one observation.
If any of these factors change, it becomes a new observation.
Adding additional information is always valuable, and as you are tracking the flight periods, add that this observation proves that it is still present in the location.
The same could be said for 2 observers taking photos of the same organism at the same place and time. It is what You see in nature.
And I do think that the period, October 24, then November 2, then November 15, is a long time in the life of a hoverfly.