This is a map made from iNaturalist Research Grade observations uploaded to GBIF, showing areas where observers have seen species that are more (or less) rare than their average.
Here, “rare” = observed in few places. The “rarity score” is the difference between an observer’s average observed species “rarity” in a cell and the same observer’s global average observed species “rarity”, averaged across all observers with obs in the cell.
Map opacity follows a sort of “confidence score”, based on number of observers and number of observations: opaque cells are full of observations from many different observers; whereas cells with few observations, or observations from a single observer, are nearly transparent.
While it doesn’t directly show “biodiversity” or ecological importance (I think there are important biases from observer behavior), I imagined it mainly as a tool to help answer the question “where can I go for my next nature trip?” - and the answer may not necessarily be “the hottest cell in the map”, but maybe a not-so-explored cell with few observation that are more rare than average…
There are probably other similar (and better) maps; if you know some, I’d like to know!
Also tell me if you have suggestions to improve this map; and whether you think the maximum resolution is too high or not: the smallest cell size is about 2 km in diameter; maybe it can reveal sensitive places? Given that it averages across all species and doesn’t give any information on what species are in a cell (and all the data are already publicly available on GBIF with far greater detail), I think not, but let me know.
Altough this ranks species by number of observations, whereas in my map the “rarity” metric is 1 / sqrt( number of cells with observations of the species).
I feel like this map is showing something interesting but I’m finding it very difficult to interpret. In my area there are no orange tiles and the nearest orange tiles are random rural areas with nothing I can see that’s special about them - they aren’t popular places to go for nature and if I filter for observations I can’t see anything special in the species list. My best guess is that there are some insects or fungi with very few observations on iNat and someone got lucky in finding them there. It’s also confusing because if I zoom in then those stop being orange and other random rural spots go orange instead.
I’m guessing that at least for rare species in my area where there are a lot of naturalists, there are a lot of people looking for them and they have been found in enough tiles that this algorithm doesn’t consider them rare.
(Edit: I just realized that it’s because the species that are rare in my area are common south of the border; this map only cares about species that are rare on iNat globally.)
Looking at one orange tile and filtering RG observations that would fall within it, the best explanation I can find is that there is one observation of an obscure plant hybrid which only has 9 observations on iNat (both of the parent species are common).
I don’t know if you have seen the map in this thread but it might be helpful inspiration for answering that question, I had some thoughts here:
How does your tool reconcile rare species with obscured locations? Are they assigned to the hexagon they randomly fall within even though they may be located in a very different habitat 10km away?
Obscured observations on GBIF have the “fake location” decimalLatitude and decimalLongitude, and coordinateUncertaintyInMeters of about 28 km.
I consider them only for cells with hex side > coordinateUncertaintyInMeters, for higher resolution they are not considered. I think this is one of the reasons for change in color between coarser and finer resolutions.
However, I’m working on a different model that should keep rarity scores more consistent across resolutions.
I hope the next model I’m working on will be less prone to be influenced from a single species.
Btw, I think this is an example of how the definition of “species” (or the splitting of a species in two new species) influences metrics based on number of species…
Thank you for the map, very interesting!!
I agree with you that many places with many tourists coming back every year are marked in purple, but I think it’s in line with the underlying idea: people that come back every year likely know well the place and know where to go, like they were living there…
