DC Metro iNat data: 2017 and observations per new species


I made some predictions in a July 2017 journal post about how many observations, species and new species would be added to iNat from July to December for the DC metro area:

In previous years, the first half's observations accounted for about 49% of the year's final total, and 58% of the species. Extrapolating that to 2017 would mean 22,632 second-half observations, or 44,639 total 2017 observations (range: 39,729 - 50,888), and 4,183 species (range: 3,890 - 4,602), or about a 150% and 120% increase from 2016, respectively. How many of those species would be new records for the DC Metro area? A rough estimate is that, based on 2011-2016 trends, a new species for the DC Metro is recorded about every 30 observations. So, if I estimate 22,632 observations will be added in the second half of 2017, that would suggest 700 new species will be added (range: 550 - 890).

How'd my predictions fare? Some good, some not so good! As of today, iNaturalist shows approximately 54,000 total 2017 observations, which is about 10k higher than my estimate. I did better with the total number of species: iNat shows 4,174 species, an undercount of just 9 species compared to my prediction. I also predicted 700 new species would be added in the second half of 2017, and I did pretty well there too, as iNat shows a difference of 717 species from July 1 to December 31, 2017.

It was another year of growth for the DC-area iNaturalist community. Total 2017 observations (n=53,997) exceeded all observations made prior to 2017 (n=53,024 obs). High watermarks were posted for number of species, observers, and identifiers. Six people broke the previous record for a single species count in the DC metro, including @krosenthal @mellis @peggyo @treegrow @ashley_bradford and the current record-holder @judygva at 1,035 species. Go Judy go!

While the overall effort (observers and identifiers) is increasing, it's becoming more and more challenging for new species to be identified in DC on iNaturalist. For example, out of a total 600 observations in 2011, about 174 species were new to iNaturalist. That means, on average, a new species was added for the DC metro every 3 observations or so. The number of observations needed to "find" a new species has climbed every year. In 2012, a new species was added every 5 observations. 2013, 8 observations. 2014, 9 observations. 2015, 13 observations. 2016, 23 observations. In 2017, we needed 43 observations on average to identify at least one species that had never been recorded in the DC area on iNaturalist. In fact, 2017 was the first year in which we recorded fewer number of new species than the year previous (~1255 new species in 2017 vs ~1326 new species in 2016).

The quantity of effort required to record a new species really varies across taxonomic groups. Here's some examples (based on stats downloaded Feb 2018), in order of decreasing effort required:
-- Amphibians (1 new species in 2017) = 920 observations to record 1 new Sp
-- Birds (16 new species recorded for DC area in 2017) = 327 observations to record 1 new Sp
-- Reptiles (5 new species in 2017) = 256 observations to record 1 new Sp
-- Mammals (6 new species in 2017) = 212 observations to record 1 new Sp
-- Ferns (7 new species in 2017) = 95 observations to record 1 new Sp
-- Arachnids (32 new species in 2017) = 43 observations to record 1 new Sp
-- Flowering plants (547 new species in 2017) = 40 observations to record 1 new Sp
-- Insects (413 new species in 2017) = 34 observations to record 1 new Sp
-- Ray-finned fish (13 new species in 2017) = 28 observations to record 1 new Sp
-- Protozoa (3 new species in 2017) = 27 observations to record 1 new Sp
-- Molluscs (18 new species in 2017) = 24 observations to record 1 new Sp
-- Fungi (146 new species in 2017) = 20 observations to record 1 new Sp
-- Mosses (13 new species in 2017) = 18 observations to record 1 new Sp

So if you want to record some new-to-iNat species for the DC metro area (say, for example, for the upcoming City Nature Challenge cc @carrieseltzer) AND you want to be lazy and/or strategic about your observation effort, my advice: get low and get wet and ignore terrestrial things with backbones. Mosses, fungi, molluscs, protozoans, and ray-finned fish would all be great targets for focused monitoring effort to find species that have never been recorded before on iNat in the DC Metro area. There appear to be hundreds of flowering plant and insect species to still identify, so keep looking at those things too. (And someone should get a microscope and start identifying the unicellular stuff!)

What are my 2018 predictions for DC metro iNat? Assuming observations and species grow at a similar rate compared to recent years, and new species become similarly challenging to find and identify, I predict:
-- 85,000 total observations (range: 75,000-95,000)
-- 5,000 total species
-- including 1,000 species that were previously unrecorded on iNat for this area

Now go outside and prove me wrong!

Anotado por muir muir, abril 26, jueves 09:38

Comentarios

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PERFECT timing, @muir! I will share this post on our CNC coordinating call today. Thank you!

Anotado por carrieseltzer hace casi 3 años (Advertencia)
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ha - very cool - we're going to have to start calling you the Oracle of Ancorage

Anotado por loarie hace casi 3 años (Advertencia)
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Great data! Thanks for the lowdown. Now I'm curious what my single species count record species was.

The problem, for me at least, with submitting fungi is that I get a very low return as far as IDs. And I don't know fungi, so it's hard for me to hunt down the IDs myself. Not many people seem to be good at it, and my submissions often just float around identity-less. The same goes for lichen.

I plan to take lots of pictures this weekend, but you guys may have noticed I can be slow to get them in here from my camera (so I will also be using my phone for plants, which I get in quickly). Is there a cut-off time for the Challenge count?

Anotado por ashley_bradford hace casi 3 años (Advertencia)
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@ashley_bradford you are currently sitting at 528 species for 2017. The previous record was Ken @krosenthal observing 437 species in the DC metro area in 2016.

That's a very good point about how submissions for certain groups have low returns on IDs (and how that affects a person's likelihood of observing more of that group in the future). It would be really interesting to quantify, but I think we would need to steal @loarie 's data wizardry hat a la the Sorcerer's Apprentice. Still, on average, I think it's interesting that with all the ranges of skills, photo qualities, and expertise across iNat observations, we're still finding a lot of new plants, insects and fungi. Interesting to think about peaks of new species added, and which groups we're on the downward slope and which groups, the peak is ahead.

Anotado por muir hace casi 3 años (Advertencia)
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@carrieseltzer when I started the journal post, I had grand plans to look geographically -- which counties have the highest and lowest return on species/observation and observations required to find one new species -- in time for the City Nature Challenge...... but alas. Good luck!

Anotado por muir hace casi 3 años (Advertencia)
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Matt, thanks again for all the great information. Your predictions are quite amazing!

Anotado por peggyo hace casi 3 años (Advertencia)
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Oh! Neat, thanks! And if I were able to invent more time, I could add a bunch more. Oh well. On to 2018...

Anotado por ashley_bradford hace casi 3 años (Advertencia)
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@muir if you wanted to cover an area in MD that hasn't had any/much activity yet in the CNC, where would you go? I'm trying to plan an outing for myself tomorrow morning but I'll only have a couple of hours, so I probably can't go far north. https://www.inaturalist.org/projects/city-nature-challenge-2018-washington-dc-metro-area?tab=observations&subtab=map

Anotado por carrieseltzer hace casi 3 años (Advertencia)
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@carrieseltzer Little Bennett! I can't believe no one has posted a single observation from this nature treasure yet: go go go!

Anotado por muir hace casi 3 años (Advertencia)
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Also Jug Bay (stay on west side of river to be eligible for CNC)

Anotado por muir hace casi 3 años (Advertencia)
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It's killing me to be missing this!

Anotado por muir hace casi 3 años (Advertencia)
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An update on new-to-DC iNat observations recorded during the dates of the City Nature Challenge:

-- Amphibians (1 new species in 2017) = 0 new spp during CNC
-- Birds (16 new species recorded for DC area in 2017) = 0 new spp during CNC
-- Reptiles (5 new species in 2017) = 0 new spp during CNC
-- Mammals (6 new species in 2017) = 0 new spp during CNC
-- Ferns (7 new species in 2017) = 3 new spp during CNC
-- Arachnids (32 new species in 2017) = 2 new spp during CNC
-- Flowering plants (547 new species in 2017) = 150 new spp during CNC
-- Insects (413 new species in 2017) = 25 new spp during CNC
-- Ray-finned fish (13 new species in 2017) = 0 new spp during CNC
-- Protozoa (3 new species in 2017) = 0 new spp during CNC
-- Molluscs (18 new species in 2017) = 5 new spp during CNC
-- Fungi (146 new species in 2017) = 31 new spp during CNC
-- Mosses (13 new species in 2017) = 2 new spp during CNC

These numbers of course are subject to change as identifications and captive statuses are revised, etc. Overall, about 220 species were added during CNC dates that had not been recorded on iNat in this area before. ~70% of those new species were plants, 15% fungi, ~10% insects. Nice work botanists! cc @carrieseltzer

Anotado por muir hace casi 3 años (Advertencia)
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Wow! That's awesome, @muir! Thanks! Check it out @dbarber @treegrow

Anotado por carrieseltzer hace casi 3 años (Advertencia)

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