Mapping distributions of iNatters via common species

[WildEdges]

I just asked for this thread to be reopened to mark the imminent dethronement of the mallard by the mighty robin (in the UK). I’ve been watching it slowly catch up over the last month or so and the race is very close now.

[jasonhernandez74]

Whoa–the Asian lady beetle is now incognito under the name “harlequin ladybird”???

[cthawley]

This is the regional name set for the species for the UK:
https://www.inaturalist.org/taxa/48484-Harmonia-axyridis

[WildEdges]

A bit of fine weather brings the mallard fanciers out of the shelter of their caves. They’re back to a 20 point lead now I will make it my weekend mission to track down some robins to try and level the game again.

[jheiser]

It’d be fascinating for someone to do an anthropological study of iNat. I’ve been conscious for several years of the significant degree of variation between different specialist communities in my state of Ohio (USA).

I started with iNaturalist as a project to ID as many species as possible on our own property, so I end up checking in observations across a variety of natural history categories. Dragonflies, birds, and spring ephemeral flowers usually attract immediate attention. As currently under discussion in another thread, non-biting midges can languish for years.

Large, ‘attractive’, and easily identifiable species end up with far more observations, and confirmations, than do small, ‘less attractive’ and harder to ID species. Major urban areas have more observations, representing a greater number of species, than do areas with relatively low population density. I would expect those observation biases to be relatively consistent across the globe.

But there are also differences in natural history community behavior that are probably random. In Ohio, which already had a relatively active odonate community, iNaturalist is used to update the state oda survey, and it has been thoroughly acculturated within that community. Consequently, the number of oda species observations is significantly larger than many other natural history categories in this region. To put the behaviors of the different communities into perspective, here are the Ohio observation counts:
-Odonata 203K
-Lepidoptera 278K
-Coleoptera 70K

Especially given the much larger number of species, why do beetles get less love than dragonflies and damselflies? The top observer of beetles has less than 1/10th the number of iNat observations in that family compared to the top observer of odonates (I did notice one person at the top of both lists). I’m sure that there are other considerations, but as a starting hypothesis, I expect that compared to dragonfly watchers, the beetle enthusiasts in Ohio are relatively less interested in putting beetle observations into iNaturalist. It is less of a ‘thing’ in their community.

FWIW, we believe that we have a very good idea of the set of odonate species that call Ohio home, but we still don’t have fully accurate county lists. The total oda observations (including the pre-INaturalist records) per county vary from a high of 15,000 to a low of under 800, which is huge for a small and ‘square’ jurisdiction like Ohio, in which anyone could leave home right after breakfast and arrive at any other part of the state before peak daily oda activity.

There are a LOT of different observation bias sources. A lot of us travelled to see the eclipse, and checked in some observations while we were there. I recently photographed frogs being bitten by mosquitoes 5 times, which I’d never seen before. It turns out that Culex territans is relatively common, but there are only 2 prior Ohio observations. Is that because they are hard to observe, or is it that people just don’t care to photograph mosquitoes?

[WildEdges]

[WildEdges]

I’ve noticed that you can also judge the seasonality of iNatters via observations of common species (in the UK). Discounting species that have a distinct season, such as flowers and some insects, you can see a pronounced spike in observations in April for many species that are fairly common all year round. I imagine that the obvious surge of life we see as spring arrives gets more people motivated to record nature but I wonder if places with less pronounced seasonality see any similar trends?

[lynnharper]

The annual and global City Nature Challenge takes place in late April/early May and adds an extraordinary number of observations to iNat over a short period. I suspect that contributes to the April spike you’re seeing.