Archivos de Diario para abril 2020

17 de abril de 2020

Alaska iNat passes 100k observations & 5k unique taxa: Part I -- seasons & species

This journal post is Part 1 of 2. Read Part 2 here: Alaska iNat passes 100k observations & 5k unique taxa: Part II -- Boroughs

Alaska iNaturalist observers passed two milestones in the past 6 months: 100,000 observations and 5,000 unique taxa1. Curious about trends, I played around with the data2 available on the iNat place page (I’ll post the data if people are interested, but see footnotes where I try to explain my method of copying and interpreting the data). If you see an error, in either the data or my interpretation, please comment below. Here’s what I learned:

iNat observers added 35 times more observations in 2019 compared to a decade ago, grew 20-50% annually in recent years, but remain modest contributors compared to other US states. In 2019, more than 34,900 observations have been posted, representing a near 35-fold increase from the 2009 total of ~1,015 observations3. Since 2016, iNat activity is increasing on average by about 50% every year. By 2018, Alaska added an average of about one hundred iNat observations and four new observers per day. This is 3-4 times below the 2019 average for US states (i.e., 389 new observations and 11 new observers per day) and the number of Alaska observations added in 2019 is about 0.5% of all US observations added.

iNat activity in Alaska is 9-10 times higher in the summer vs winter. Unsurprisingly, given our latitude and climate, Alaska iNat activity is highly seasonal with a burst of observers and species in the summer months of June, July and August. Summer accounts for about 63% of all observations and about 82% of all taxa that have been observed in Alaska. Conversely, winter observations made from October to March account for just 13% of all observations. Of the total number of iNat observers that have posted in Alaska, only 16% have made an observation during the winter versus 73% in the summer. Comparing the number of observations and observers by monthly average, there is 9-10 times more iNat activity in the summer compared to the winter. New observers making their first observation in Alaska show the same pattern of seasonal dormancy and activity: 67% of new observers in 2018 were added during the three months of summer versus 8% added during a half year of winter.

One new taxon was recorded about every 56 observations in 2019. As the most observable species have been documented by the iNat community over time, the number of observations required to document a unique taxon, previously unrecorded in Alaska on iNaturalist, has steadily increased. From 2009-2015, a new taxon for Alaska (species or above) was recorded every 11-12 iNaturalist observations uploaded. In 2016, however, the average number of observations needed to record a new taxon increased to 21 observations, then 32 observations in 2017, then 43 observations in 2018, and most recently, 56 observations in 2019.

Approximately 13,205 species are known to occur in Alaska from checklists, and a very rough estimate is that iNat observers have observed no more than a quarter of them. Species checklists for Alaska are available for birds, mammals, amphibians, fish, non-marine arthropods, vascular plants, mosses, liverworts, and lichens from the following online sources:

Combining all these groups, iNaturalist observers have documented around 3,324 unique taxa, or approximately 25% of the combined checklist species total of 13,205 species. This should be considered a very rough estimate because (a) the various checklists and iNaturalist are using different taxonomies and/or contain taxonomic errors, (b) in a few cases, iNaturalist counts taxa that the checklists for various reasons do not (e.g., bison; hybrids), and (c) I am comparing species totals and generally not matching individual species. If you are able to look past those data issues, vascular plants, mammals, and birds are covered the most by iNaturalist observers in Alaska, followed by liverworts, mosses, lichen, fish, insects and arachnids.

99% of resident and regularly occurring Alaska birds have been observed, and iNat coverage appears to decrease with increasing rarity. Birds are a relatively well-covered group by iNaturalist observers in Alaska. For example, 331 bird taxa have been observed at the time of this journal post. iNat observers have covered about 99% of the Alaska checklist of resident bird species and regular visitors (checklist maintained by UAF and last updated January 2020). iNat observation coverage appears to decrease with increasing rarity. For example, iNat observers have recorded 78% of bird species considered rare (defined in part as annual or possibly annual in small numbers, most at the perimeter of Alaska), 20% of bird species considered casual (defined in part as not annual, beyond the periphery of annual range, but recur at irregular intervals), and 2% of bird species considered accidental (defined as one or two Alaska records, or none in last 30 years). Because the most observable bird species have already been documented on iNat, the number of new taxa added every year is relatively modest: on average, about 10 per year since 2008. Relatedly, the number of observations required to document a new taxon for Alaska is higher for birds than any other comparable group I looked at. In 2019, on average, a previously unrecorded bird species for Alaska was added every 860 iNat observations. Top AK bird observers: @gwark (4151 obs, 227 taxa), @sitkaconnor (1580 obs, 212 taxa).

A little less than three-quarters of Alaskan vascular plants have been observed on iNaturalist. iNaturalist observers have recorded about 73% of the species total on the Alaska Provisional Vascular Checklist (1304 species on iNat vs 1780 on the checklist). In 2019, a new taxon was recorded on iNaturalist every ~77 vascular plant observations. Dicots are generally monitored more widely by the iNat community (79% of the checklist total) compared to monocots (59%). Species-poor groups like quillworts, horsetails, conifers, and ferns are relatively well-covered (all 90%+), as are groups like roses, buttercups and orchids. Grasses, sedges, and mustards are less well-covered (iNat species totals are 40-55% of the checklist species totals), with asters and legumes somewhere in between (~60-70%). In terms of rarity and observation coverage, I did not attempt to correlate Natural Heritage ranks for Alaska -- S1 through S5 -- with iNat observations, but I’m curious if the same pattern holds as bird observation coverage and checklist categories of rarity. Top AK vascular plant observers: @gwark (5064 obs, 465 taxa), @jasonrgrant (1368 obs, 434 taxa).

About 72% of Alaskan mammals have been observed on iNaturalist. iNat observers have recorded about 72% of the mammal species total from the wildlife data portal of the Alaska Center for Conservation Science, with about 25-30 species of rodents, shrews, bats, and cetaceans still to be observed on iNaturalist. In 2019, a new taxon was recorded about every 400 mammal observations. Top AK mammal observers: @madhipp11 (94 obs, 34 taxa), gwark (482 obs, 28 taxa).

About 41% of known Alaskan liverworts and 28% of mosses have been observed on iNaturalist. iNat observers have recorded 44 unique taxa of liverworts (Phylum Marchantiophyta) and 160 unique taxa of mosses (Phylum Bryophyta). In 2019, a new-to-AK-iNat taxon was recorded every 63 liverwort observations, and a new moss taxon every 27 observations. Top AK liverwort observers: gwark (235 obs, 36 sp), @kilasiak (39 obs, 24 sp). Top AK moss observers: gwark (739 obs, 113 sp), paul_norwood (225 obs, 43 sp).

Very roughly, no more than 27% of Alaskan lichens have been observed on iNaturalist. iNat observers have identified around 225 unique taxa of lichen out of 835 species known to occur in Alaska. (Because lichens do not form a monophyletic group, and some lichen families contain non-lichenized members, the percentage of known species and # of unique taxon recorded is more of a rough approximation compared to other groups. I'm not going to attempt to calculate the # of observations to record a new-to-AK-iNat species in 2019, nor the top observer. Lichens, glorious mess.)

About 26% of Alaskan fish have been observed on iNaturalist. iNaturalist observers have recorded around 26% of the species total from all the taxa reported from Alaska in FishBase, and in 2019, a new taxon for Alaska was documented every 35 iNaturalist fish observations. Approximately 340 species of bony fish have yet to be posted and identified on iNaturalist, plus another 26 species of hagfish, lampreys, and elasmobranchs. Top AK fish observers: @paul_norwood (127 obs, 52 taxa), gwark (203 obs, 51 taxa).

<12% of Alaskan insect and arachnid species have been observed and identified on iNaturalist. There are a lot of Alaskan arthropods that iNat observers have not found and identified yet. Based on what information is currently available, a very rough estimate is that iNat observers have recorded about 12% of the known insect species in Alaska (916 species on iNat vs 7440 species on the Draft Checklist of Non-Marine Arthropods of Alaska) and about 10% of arachnids (102 vs 1002). Given the degree to which the checklist is considered incomplete and provisional, the actual percentage is likely much lower. Top AK insect observers: gwark (3270 obs, 276 taxa), @muir (814 obs, 147 taxa).

Within the insects4, the Odonata are among the groups best covered by iNat observers (~74% of species on the Draft Checklist, 25 out of 34 species, have been observed on iNat), followed by the Orthoptera (~48%, 10 out of 21 species), and Lepidoptera (~43%, 366 out of 849 species). Conversely, iNat observers have recorded only 5-10% of speciose groups like the Hemiptera (56 out of 611 species), Hymenoptera (98 out of 1187), Coleoptera (178 out of 1753), and Diptera (146 out of 2450). In 2019, a new insect record for Alaska iNaturalist was added every ~29 observations and a new arachnid every ~24 observations. Within the insects, a new taxon was added every 38 Hymenoptera observations posted to iNat, a new Lepidoptera every 33 observations, a new Diptera every 19 observations, and a new beetle every 14 observations.

Seven out of eight Alaskan amphibian species have been observed. A handful of major taxonomic groups have few known representatives in Alaska, and unsurprisingly their iNat coverage is highly variable. For example, there is one chimaera species (i.e., the spotted ratfish) and it has been observed (100% coverage), whereas there are seven jawless fish species and only one has been observed (14%). There are nine known millipede species and four have been observed and identified (44% coverage). Among these types of groups, amphibians are well-covered by iNat observers. There are eight known amphibian species and seven species have been observed (88% iNat coverage), with only Ambystoma gracile yet to be found and identified.

Part II will look at iNat observations and observers by borough. (spoiler: Sitka features heavily!)

Flagging for some AK iNat observers who haven’t been tagged yet: @kilasiak @rolandwirth @kljinsitka @mbowser @cedarleaf @awenninger @connietaylor @blainespellman @sitkarowan @troydeclan @old-bean-adams @mckittre @naokitakebayashi @akfrank @jdmason @robertweeden @dssikes @ahaberski … and some other iNat’rs @carrieseltzer @treegrow @jakob @gyrrlfalcon @loarie. Apologies in advance if you consider this tagging to be spam.

1 100,000 verifiable observations was first passed on 08-September-19. Conversely, the 5,000 taxa milestone has been “nearly there” for months afterwards. I started drafting this journal post in November when the number of unique Alaskan taxa surpassed 4,950. The total steadily climbed to around 4,990, and then dropped some, and dropped some more, until it was around 4,960 unique taxa before rebounding upward again. The taxon total seems to take two steps forward, one step back (sometimes three steps back) for weeks at a time. Three months later, on 19-Feb, observation and unique taxa simultaneously passed 110k and 5k, respectively. Again, the taxon total backslid below 5,000. The specific cause of these downward fluctuations isn’t obvious, but presumably it’s some combination of identification revisions, deletions of observations or user accounts, taxonomic updates, updates to data quality, etc. Finally, sometime around 10-March, the 5k unique taxa milestone was surpassed (again) and the achievement has since appeared resilient to fluctuations.
screenshot 19-Feb-20
screenshot 7-Mar-20

2 I manually copied the data from on 15-Nov-19, when it looked like both milestones were imminent. Manually copying data is admittedly a flawed method, vulnerable to data entry error, time-consuming, and produces a dataset that’s very quickly out-of-date. I don’t know how to access the iNat API, but I have a basic understanding that if I did, that would be a better way to source the data I’m interested in. Alas. On 7-Mar-20, I updated that totals for several of the major taxonomic classes of observations.

3 The 2009 total (and all following years) includes observations added after the year in question. In fact, the first iNat observation in Alaska wasn’t posted until 12-January-2011 (a humpback in Resurrection Bay observed in 2005 by @msr), approximately three years after iNat came online. Proportionally, the biggest year of recent growth was 2016-2017, and there is probably an interesting analysis to be done of how yearly totals accumulate over time (e.g., what % of 2015-dated observations were added in 2015 vs 2016 vs 2017 and so on).

4 FWIW these data are a few months out of date at the time of this journal post, and were copied around 15-Nov-2019.

Publicado el 17 de abril de 2020 a las 04:42 AM por muir muir | 65 comentarios | Deja un comentario

19 de abril de 2020

Alaska iNat passes 100k observations & 5k unique taxa: Part II -- Boroughs

Photo by jimmywayne CC BY-NC-ND

This is the second part of a journal post marking AK iNaturalist reaching two recent milestones: 100k observations and 5k unique taxa. If you haven't yet, I would encourage you to read Part I first for background, trends since 2009, seasonality of iNat activity, observations by species groups, and the last remaining Alaskan amphibian to not be IDed on iNat.

An iNaturalist observation has been made in all 29 boroughs and census areas (the Alaskan equivalent to counties, hereafter simplifying to ‘boroughs’). As of 17-Nov-2019 (when I copied the data), the boroughs with the most amount of iNat activity are Sitka, Kenai, and Anchorage. The boroughs with the least amount of iNat activity are Bethel, Kusilvak, and Bristol Bay.
Alaska boroughs and census areas 2008-13

More observers & more observations per borough → more taxa recorded on iNat. In general, there’s a positive relationship between the number of taxa recorded in boroughs on iNaturalist and the number of observers (R2=0.47) and observations (R2=0.87). For every additional observer in an area, roughly about 13 additional observations and 1.5 additional taxa are expected to be recorded on iNaturalist. The boroughs with the most observers? Anchorage (1,023 iNat observers; Alaska's largest population center with almost three times the residents than the next biggest borough), followed by Kenai (910 observers). The boroughs with the most observations? Sitka (38,505 observations), followed by Kenai (12,526 observations). The boroughs with the most taxa recorded? Same pattern as observations: Sitka (2,740 unique taxa), followed by Kenai (1,680 unique taxa).

More people living or visiting a borough for nature → more iNat observers. What explains variation in iNat activity across Alaska boroughs? I spent a bit of time compiling datasets on factors that I suspected might be important: population size, area, visitor volume, visitor volume engaged in nature activities (including wildlife viewing, birdwatching, hiking), broadband service1. Of those, the two factors that seem the most predictive2 in terms of explaining # of iNat observers are (a) borough population, and (b) number of visitors that engaged in a wildlife viewing activity in the borough3. Multiple regression analysis indicated that those two predictors explained a decent 84% of the variance in the number of observers between boroughs. So, there are more iNaturalist observers in boroughs with more residents and more visitors that want to see wildlife -- makes sense, right? This appears true even when controlling for other factors.

More people living or visiting a borough ≠ more iNat observations…. except…. . In contrast to iNat observers, the same pattern does not hold true for iNat observations when looking across all boroughs. In fact, none of the factors I looked at significantly explained differences in observations between boroughs EXCEPT when I dropped a single borough from the analysis. When I looked at all boroughs except for Sitka, the importance of population size and wildlife-viewing visitors re-emerged as significant variables, with a simple model explaining 75% of observation variance4. So, what makes Sitka special?

The Borough of Sitka contains about 1% of Alaska’s population, 0.5% of the state’s area, and >37% of its iNaturalist observations. Sitka has a bit more iNat observers than one might expect based on population or wildlife-viewing visitors, but it has a lot more iNat observations -- so many that it confounds state-wide patterns and analysis mentioned above. You don’t need to run a regression analysis to notice that Sitka iNat is exceptional within Alaska, maybe even the only robust iNat community in the state (if you think differently, however, please feel free to correct me). In the comments of Part I, uber-iNat’r @damontighe said, “@gwark and the rest of the super community there is really showing what can be done by organizing people to contribute and being on top of helping identify things as they roll in. I have yet to take iNaturalist observations in a location that got as much identification help as I had in Sitka.” Over email, I asked @gwark what makes Sitka special, and with his permission, am posting his response here (lightly edited for clarity, like some off-brand @tiwane):

Part of it is my compulsiveness - in addition to the 8000+ observations I've made since I really adopted iNaturalist as my primary way to record natural history observations in at some point in 2016, I've been working through all my photos going back 20 years, 99% of which are from Sitka.

Although a few of us had dabbled with iNaturalist previously, the first person in Sitka who really started using it extensively was Paul Norwood at the beginning of 2015. When I saw how it was working for him, I was convinced that iNaturalist was the way to go.

rolandwirth and kljinsitka both got into iNaturalist during the All Species Community Big Year project that we did in 2017 ( They both really took to it, and have been quite active since that time.

Several other people with >50 observations who are based in Sitka participated in the big year project. A handful have continued to occasionally post observations since then.

I know that I regularly encourage folks to post things to iNaturalist, and I am pretty sure paul_norwood, kilasiak, rolandwirth, and kljinsitka do as well.

I'm not sure if it makes much difference in terms of on-going participation, but I'm pretty compulsive about going through all the observations that come in and trying to identify things. I actually look at all observations from south coastal Alaska (and Haida Gwaii, as well) - but I'm most knowledgeable about things that occur in Sitka, and so am more likely to be able to ID things the closer they are to Sitka.

I think gwark and damontighe hit on a key point re identification help. I wouldn’t really know how to look for the publicly accessible data to confirm it, but my guess is that strong, durable iNat communities are created by enough exceptional individuals that are both creating observations, but also doing a lot of identifications and engagement on other people's observations (as well as connecting with people IRL). People that aren't engaged online, or aren't organized around this platform in person, probably have a much higher likelihood of drifting away. Kudos to Sitka for building community.

I also like the link to the big year project as a starting point for some people to become active users. I think the data are pretty clear that the City Nature Challenge (CNC) brings in a huge influx of iNaturalist users, a fraction of which become longterm active members of the community. I had very briefly talked to the CNC organizers last year about establishing a challenge in Alaska, but the CNC dates -- end of April -- just wouldn't work well for most of the state I think. For those of you Alaskans who didn't join through the Sitka Community Big Year, I'd be curious if you're willing to share: how did you become an active user on iNaturalist?

Tagging folks who commented on Part I: @rolandwirth @loarie @whaichi @carrieseltzer @gyrrlfalcon @awenninger @choess @treegrow @mckittre @connietaylor @paul_norwood

I had planned a Part III to forecast Alaska iNat observations into the future (as is my wont), but I think the spread of the novel coronavirus makes the exercise feel a little less fun and a bit ‘heavier’ now. There’ll be a lot fewer visitors and residents moving around in 2020. Fewer people won’t bother some Alaskans (less crowding on our highways/trails/rivers should be a nice break for us and nature), but it’s going to be a hardship for a lot of neighbors and communities, and an atypical, possibly quite grim year overall.

1 Sources (some more out-of-date than others): Borough Population (copied from Wikipedia 12/1/19: American FactFinder Population. US Census. Retrieved 2019-10-15); Visitor Volume + Wildlife Viewing in Community % + Birdwatching in Community % + Hiking/Nature Walking in Community % (2016 Visitor Volume and Profile; Broadband availability (> 768 Kbps download/ 200 Kbps Upload speeds) (% of households served) (2014)

2 Multiple regression analysis was used to test if borough traits significantly predicted borough observers. The results of the regression indicated that two predictors explained 84% of the variance (R2 =.84, F(2,25)=66.50, p < .000001). Borough population significantly predicted the number of iNaturalist observers (β= 0.003, p < .0000001), as did borough visitors who engaged in a wildlife viewing activity (β= 0.002, p < .000001).

3 The number of visitors that engaged in a hiking or nature walk activity in a borough was also positively related to iNat activity, but was no more significant nor explained more variation than the related variable related to visitors engaged in a wildlife viewing activity. My guess is that the two variables related to visitor nature activities are broadly similar enough that they indicate similar things about the borough, and I chose to focus on the one that appeared to explain more variation. Broadband access and total number of visitors were not significant variables, including when controlling for other factors.

4 Multiple regression analysis was used to test if borough traits significantly predicted borough observations. Dropping Sitka from the analysis was the only way to find a significant model. The results of the Sitka-less regression indicated that two predictors explained 75% of the variance (R2 =.75, F(2,24)=36.27, p < .00000001). Borough population significantly predicted the number of iNaturalist observers (β= 0.03, p < .00001), as did borough visitors who engaged in a wildlife viewing activity (β= 0.02, p < .0001). Models that included total visitor volume, visitor volume engaged in hiking/nature walking, and broadband access did not substantially increase R2.

Publicado el 19 de abril de 2020 a las 06:26 AM por muir muir | 4 comentarios | Deja un comentario