You probably want to check out the Plants Out of Season project, it looks for exactly this sort of info – what a known plant looks like on its “off season” or basal stages.
Ooh I will thanks
I come down strongly on the “You can’t use iNaturalist data to estimate abundance” side of the argument. Not that it’s never possible, but you need many qualifications and assumptions about the number of observers, what the observers photo, the likelihood of species X being photo’d if present, etc. I think iNaturalist is great for presence/absence information and for some things duration (earliest, latest, etc.). Not abundance.
Imo the only downside is how map will look, no matter if many people see things at once, or one person throughout time, especially considering how observations are rarely aligned with each other, I don’t bother specifically about abundance which won’t ever be true because of humans, but it just creates a false impression about this particular spot and e.g. number of mature or juvenile specimens that appear there, especially if observations are not from one day, you can imagine there being a forest when there’s a single tree, or it can affect observer too, as looking at map of their observations, they will see like ten oaks in this spot, which could make them feel they observed already enough oaks in the area (sure, if you do that with one plant only, chances are less, but still even when you know it’s that particular plant, your brain still falls for many observations you made), so this could lead to less observations of more individuals while more individuals at one time is a more interesting (useful for iNat) data.
All true, @Marina_Gorbunova , but I think of minor importance. Probably a smaller apparent distortion than the facts that the Oregon city of Corvallis and the Russian City of Moscow both looks like the centers of abundance for most organisms that people post of iNaturalist or donate to natural history collections. Or the apparent concentration of most species along roads, where people definitely concentrate. These are just more things people using iNaturalist (or herbarium) data have to think about, preferably before analysis.
Right, those are different scales of same problem, especially if there’re not many plants to observe at all, but I hope % of same plants observed overall is not that high, it’s usually big old trees that get attention. With that I hope that usually when you look at map, even though it reflects one user’s action, it also depicts mostly different individuals (so chances are higher to find another one), but it’s another thing to always keep in mind when using iNat. There’s a Velvet Scoter with damaged wing and it moves on the river back and forth throughout year, so you could guess that city is filled with those rare ducks, especially with obscuring of species going on.
Yes, I can believe the range of rare things can be exaggerated a lot! (Although, in a sense, that duck crossing back and forth is outlining its range there.) There are lots and lots of dots for cultivated plants (not marked as such) at or near schools, too. The same individuals uploaded dozens and dozens of times.
We need to move to that topic about iNat bias , common species are very affected too, easiest example is Mallard with 250+k of observations and big chunk of its range have no observations (and people live there), or who knows how many species have no observations in this range, when about similar area in Sahara has around 2k observations, which is still very low, but 100 times more.
This kind of bias is not restricted to iNat either, it occurs with herbaria as well (unless they’re doing specific studies). For example, in my area the herbarium has 26 specimens lodged for Eucalyptus campanulata and 25 for E. codonocarpa for my region. This tells me nothing about abundance even in a rough sense. E. campanulata is common and very easy to find; E. codonocarpa is uncommon and considered near threatened. So looking at just the number of specimens lodged with the herbarium (call them observations) is misleading. I think it’s the same bias as can be seen on iNat and it’s not a bad thing, as you know, it’s just something to be aware of. I think we’re on the same page here and I’m certainly not disagreeing with you, I thought I’d just add another example :)
Sure! It’s very interesting to see how iNat data is “behaving” the same way strict scientific collections do!
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