How many individual plants should I tag of the same population?

Hello - relatively new amateur user here, so take it easy on me :grinning:. I have recently been seeing a ton of Zizotes Milkweed popping up around my neighborhood, and I’ve been doing separate posts for each plant. Yesterday I found a couple of clusters with 10-12 plants all within a few feet of each other. Is it helpful for me to post each plant separately? Or should I just pick one and post it? I love documenting them and contributing data, but I wasn’t sure if posting every plant I come across is helpful or if it will skew the data and make it look like there is a huge population in my neighborhood, whereas someone in another part of town might only post about it once. Thanks!

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Under formal iNat rules, every observation must be for one and only one individual. If you see 2 plants a meter apart and want to document it, you need to do separate observations for each.Likewise if you see the same individual today and tomorrow, that is supposed to be separate observations.

Openly, this is an approach that does not have broad or unanimous agreement on the site, but what you are doing (even without realizing it) is following the site rule. Many users dont have the patience or time to document every single individual they encounter as separate records, but technically that is what the site wants.

If anyone pushes back or tells you to stop doing what you are doing, you can point them to the site rules on observations ( https://www.inaturalist.org/pages/help#observations1 ), or even this.

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If there’s a cluster, I’ll pick a representative individual and take photos of just that one. If there are a number of individuals spread out over an area, I’ll usually just pick a few and take photos of them.

I’ve also taken photos of “clumps” of things that are growing where I can’t get photos, but they’re identifiable in the photo, like Purple Loosestrife or stands of Aspen.

I treat insects the same way. If there are a bunch of aphids on a plant, I’ll just take a photo of them all next to each other, since it wouldn’t be very practical to get a photo of every aphid by itself. This also applies to ant colonies and other similar groups.

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Thanks! I wouldn’t tag a group of plants as one post either way. I was more wondering if I should just pick 1 plant out a group of say, 10 individuals, and post it as a representative (maybe with a note saying there are more nearby), so the species is marked on the map as being located in the general area, or if it’s more useful for people to see 10 separate posts. I guess it just depends on the plant and situation?

There is not any ‘right’ answer to your question. The ‘rules’ on the site are:

  • the photo in a record must be of the individual you are documenting and be from the place and time you document it.
  • every photo in a single record must be of only one individual (note regarding the comment about the aphids above, basically what you are doing in cases like that is actually documenting one of the aphids in the photo, if you wanted to technically it would be valid to repost the same photo under multiple records saying, this is for the leftmost one, this is for the 2nd to the left one…)
  • there is no real consensus about what represents an appropriate distance between individuals that warrants documenting them, as I said above, technically if they are a centimeter apart, and separate individuals, it is required to document them as separate records if you wish to document both.

So long as you follow those 2 guidelines, you can post as many as you want or have patience to do.

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Thank you!

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my plea to anyone reading: please don’t do this

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Yes, I am often sighted on the ground photographing “belly plants” growing together in masses, and I don’t have the macro capability (or the gardening desire) to isolate just one. So I often post a photo showing multiple individuals of the same species, and leave it to the viewer to decide which “one individual” is the subject of my observation. If I’ve done my job well, it’s never an issue for subsequent identifiers. I don’t re-post the same photo, with the same ID, for each individual in the photo. That would just get them flagged as duplicate observations!

I imagine others who observe smaller organisms often have the same approach to the site rules.

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You don’t have to do it, and I agree don’t, but if you want to, no one can tell you it is wrong or against the rules.

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So long as you state what you are doing they should not get flagged or the flags dismissed as again it meets the rules

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If you want to take data for conservation or monitoring purposes using iNaturalist, I think the best one-size-fits-all approach is to take one observation per ‘patch’ and make thorough annotations (or use custom fields) to describe it. Number of plants, area, % cover, phenology, etc. are all potential things to consider

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As said above, it’s your choice. There is value in documenting each individual, which allows monitoring of very fine-scale changes in the population over time. There is also value in recording a representative individual here and there for larger scale mapping.

For a clump, I personally prefer to photo the whole clump and do close-ups of one or some individuals. Reporting how many plants are in the clump is valuable, though not necessary.

Milkweeds tend to form clones connected by rhizomes (underground stems) so a patch may – or may not – be a single genetic individual. Just to complicate things.

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I tend to take a photo of the clump and then later photoshop a selected individual (the most in focus, for ex) and post both with the cropped enlarged shot first. It helps the computer ID program more I think, and the people looking at it. In the case of plants, I may crop several parts of the image to show diagnostic characteristics. I especially crop when I have multiple species in the shot. All of which I realize wandered off topic :grin:

I think a lot of research centers on 2 main foci in recording - species distribution and population density. The first is accimplished by posting even one observation. The second is harder. Unless you record every individual, the data aren’t useful as a count, especially as there is no consistent approach to this on iNat. If you are doung a census for yourself, then you might choose to post every individual and tie it together in a project, but otherwise there isn’t a good way to indicate to others that that is what you’re doing.

All that said, there are, as others have said, absolutely no rules against it. You might choose to document all for several years an go back and see how their locations or densities have changed over time.

For me, again as others have said, i haven’t the patience to do multiple individuals unless there is something particularly interesting about them. There are usually too many other things clamoring to be photographed!

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That all depends on the variety of shots of a species being posted by others on the site. If there are enough correctly identified shots of multiple individuals of the same organism, then Computer Vision will learn to recognize those too. Likewise with shots where an organism takes up a relatively small part of a wider habitat shot – again if there are enough similar photos all correctly identified. If we all took well-cropped photos of a single organism, then yes, one would have the best chance for a correct Computer Vision ID by submitting those same kinds of images.

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An interesting potential use of iNaturalist with many photos of the same species close together would be a demographic study. Can you find a seedling and record it as a first-year adult and again when it first flowers? Does it flower each year? Photo it each year to record how long it lives? There’s a lot of mathematical modelling about the life history of perennial plants, but there are relatively few multi-year studies of actual plants that can be used to test these models.

Of course, if you were doing such a study, it would be good to state that in the comments and to link to earlier photos of the same plant.

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One response I’m a little surprised to not see here so far is to approach this like scientists do for plants. Of course, this can be modified for any individual or researcher’s use. The concept? Decide on what you want to call “a population.” For example, some researchers use a 1 foot or 1 meter buffer to define an individual. However, this doesn’t work well for Aspen species which can form large clones. It might work well for Echinacea, which is not rhizomatous but does form small clumps. I saw one paper recently that uses a 1 kilometer buffer zone to define populations; that’s a common practice that works for many plant species but might not work well for chickadees. Other measures such as time can be treated differently.

I had one experience I found disappointing. I found a new population of a plant on the Savannah River Site in South Carolina five miles from another location of this federally listed endangered species. I considered this a new population. However, I was told that the US Fish and Wildlife personnel (never confirmed by me) considered these two and perhaps other “off site” groups of plants as “colonies” of the same population. Why? The report was, "If we have too many populations, then we would have to propose delisting this plant as an endangered species.

My thoughts? If you have more populations that would indicate you need to delist, it is more reasonable to delist than to change your definition of a population.

However, for the problem at hand, the answer is simple. I population is whatever a competent scientist defines it as. With a definition, your work becomes repeatable. For this website, the basic unit is an “observation” as defined by the rules outlined above and elsewhere on this site. How someone defines a population is up to the individual. I’ll give you an example of how I use this site.

I’ve been documenting Prairie Dock and Compass Plant at any site I find them in Baxter County, Arkansas, USA. If I go back a different year, I try to GPS at a slightly different part of the population. If you zoom in, you could find the sites I’m discovering. If a site is large, such as five miles long along US Hwy. 62/412 between Yellville and Harrison, I document several observations. If I go back in different years or find more plants I try to spread out the reporting points (Hwy. 5 south of Mountain Home has a couple examples). I first used GIS in 1994 to document rare plant sites at the Savannah River Site. I soon realized that I could spend days searching for the edges of some populations of some species. It all depends on how much time you want to spend documenting the edges. ’

As someone hinted above, the decision becomes an economic one. How much time do I have to study Carex sedges in Arkansas? After 7500 species, 4000+ collected by me, I decided I had done enough on that topic. I could spend my life documenting sites for Carex umbellata in Arkansas, a former S1 species (rarest state ranking) now known in more than 2/3 of our counties and covering more acres than any other Carex in Arkansas! So, my answer is, decide what you want to accomplish and define a population in a way that suits your needs. No one answer will work for all species in all situations.

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A few more thoughts… This reminds me of the concept of “points, lines, and polygons” when using a geographic information system (GIS). All things on a map are mapped with points, lines, and polygons. Observations are, by definition on this website, points. A series of points can represent the extent of a population, allowing you to draw a circle around the points as a polygon, often called a site, colony, population, etc. for plants and animals, but might represent a state, county, pond, building, or other polygons in GIS. Lines might work well for roads, but if you use polygons for roads, you can calculate how much area is consumed by roads. For example, more than 1% of earth is now paved over by roads, structures, etc. So, again, decide on your purpose, and take enough observations to meet your goal. I recorded bird nests on more than 10 separate days (sometimes every other day for my use) at the same site, for example, because my goal was to document hatching, fledging, and loss of the nest or individuals, for example.

I’m using an Observation Field called “Group Size” to note the number of observed individuals of the same species.

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I have a spruce budworm trap in my office right now with >600 moths in it. I’m going to take a picture of the contents and repost it >600 times. I’m going to tag you in all of them.

(Just kidding…I’ll tag cmcheatle instead)

(Just kidding)

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I have a (small) display of pinned moths and insects representative of what we find in our area, and it really pangs when the particularly doe-eyed children look up at me and ask “did you kill them?”. There’s maybe 50 tops… singles or M/F pairs of a diverse range of taxa… No matter how much I say to myself that others spray to kill flies and cockroaches, I’m still left feeling like a mass murderer!

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