How to handle repeat species

I also have my personal favourites and take photos of them every day I see them. Sometimes it may be the same individual, sometimes there’s no way to tell. I do stop short of posting multiple photos of different individuals of one species observed on the same day unless there are noticeable differences (usually life stage or sex)


I often photograph repeat species… even Canada Geese. I walk the same trail on an almost weekly basis and it helps me track dates/appearances from year to year as other factors, e.g., vegetation, change.


Someone after my own heart. Nature changes almost daily. There is always some change to note. One need not venture far from home.


As many folks have pointed out, do what you feel most comfortable with. This comment is to add perspective from a a scientist who uses iNaturalist data. Recent research on “eco-niche modelling” shows that models were more accurate when using data for areas where organisms had been observed in multiple years. So if an organism has been reported from a location in previous years, but not the current year, it would be helpful to take the observation.
Similarly, for species that migrate or only show up in areas sporadically as well as species with different life stages like flowering plants and insects, having monthly data is helpful. The monthly data is known as phenological data and can help researchers map out bloom periods, migration dates, seed collection, etc.
Using the Canada Goose as an example, taking observations every month they are present would allow researchers to know if the area is part of the wintering grounds, or just summer grounds. Similarly, if folks were able to capture eggs and goslings, researchers can use that data for local breeding periods.
So to summarize, yes do what you feel comfortable with but do know the data are useful for many things if they are repeats.
-Shaun McCoshum, PhD


I found this discussion very helpful. Thanks to all.

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I am not sure if this was mentioned but one thing to point out is that, though repeat species observations provide important phenological data, those data don’t have to come from one person.

The users of iNaturalist collectively are giving more phenological data than even the most dedicated individual user. Of course that shouldn’t discourage any individual from repeat species observations; it’s cool to track the phenology yourself, and it might be how you prefer to iNat, and of course it can only be a good thing, especially for less observed taxa or less explored locations.

Just saying you shouldn’t feel compelled, because the user base of iNat has it handled, as I think was the intention (crowdsourcing data).

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I’m more and more falling into the camp of ‘if you see it, snap it’ (assuming that it’ll hold still long enough).

I have a particlar love for dragon- and damselflies; I’ve been photographing them since I was a kid. Up until recently, I was likely to pass over an example of an ode that I had shot previously. (Sooooo many pictures of blue dashers…) But then, the IUCN Redlist was updated, showing that some 16% of odonata species are at risk of extinction. On top of that, there are over 1,700 species of dragons and damsels for which for there isn’t enough data to assign a conservation status.

With that, I’ve come to the conclusion that documenting repeat species is also useful. The practice allows for an assessment of population robustness and changes in distribution – neither of which is going to become less important any time soon. Of course, I’m not going to try and say that this is the only scientifically valid way; if there’s one thing that I’ve learned from being attached to a biostatitician, more data is generally useful, but some data is almost always better than none. (Or, as The Doctor just said, even bad data tells you something.)

Now, I just have to make sure that snapping yet another cooperative blue dasher doesn’t cause me to miss something that I haven’t actually seen before – like almost happened this week with an eastern amberwing! :grinning:


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