5000+ species in DC Metro
Around the same time the whole site hit 5M observations, DC-area iNaturalists reached their own milestone last week as the 5000th species was recorded and IDed within the Washington Metropolitan Area. The community crossed the 5k threshold on 26-June-17, and currently sits at 5,024. (Note that here and elsewhere, I am referring to verifiable observations of non-captive species.) This overall count can fluctuate independent of new additions as species identifications are corrected/changed.
A few iNat stats from our area:
Annual iNat observations and taxa have increased every year since 2011, with the biggest jumps (~5-fold increase in observations) from 2011 to 2012, and 2015 to 2016. From 2012 to 2015, the number of observations steadily increased by about a third each year.
Overall, @treichard has recorded the most observations (n=3,697) within the DC metro, and @peggyo the most species (n=889). In terms of most species recorded in 12 months (= Big Year, all species version), @krosenthal IDed 430 species in 2016, but incredibly @judygva, in only the first six months of 2017, has smashed that previous high with 519 species so far. Compare the leaderboards below, and you can see that judygva is not the only newcomer having a big impact: 80% of the top five spots, for both species and observations, have turned-over from 2011-2016 to 2017.
Observation Leaderboard 2011-2016
(1) treichard [3,215 obs]; (2) muir [2,921]; (3) @calopteryx [2,629]; (4) @treegrow [2,608]; (5) rosenthal [2,383]
Species Leaderboard 2011-2016
(1) calopteryx [845 spp]; (2) treegrow [736]; (3) @drkilmer [731]; (4) treichard [704]; (5) krosenthal [698]
Observation Leaderboard 2017 (up to 1-July)
(1) @belyykit [1,289 obs]; (2) @elliotgreiner [1,168]; (3) @mellis [972]; (4) judygva [775]; (5) treegrow [666]
Species Leaderboard 2017
(1) judygva [519 spp]; (2) mellis [427]; (3) peggyo [325]; (4) krosenthal [257]; (5) elliotgreiner [242]
A couple more musings:
(1) In the context of iNat activity, the Pareto Principle, also known as the 80/20 rule, might suggest that 80% of iNat observations should be expected to come from 20% of the observers. Since 2012, the DC-area iNat community has been even more imbalanced, averaging 10% of observers contributing 80% of annual observations. I don't know how that compares to other places, or what it might indicate.
(2) We're at the year's halfway mark, so allow me to try to predict what happens in the second half of 2017 in the DC-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).
