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. (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.

Posted by muir muir, April 17, 2020 04:42



Thanks so much for putting this together.... both informative and inspiring to find more critters!

Posted by rolandwirth 12 months ago (Flag)

This is great, thanks for pulling it all together!

I'm curious how Alaska is doing in observations per capita. A quick check shows that in 2019, Alaska had about 0.02% of the US population, so if 0.5% of observations in the US came from Alaska, we're doing pretty well. Of course it's complicated a bit by the fact that many of the observations are probably from visitors, so it's not necessarily fair to compare the state population directly..

Regarding (new) species - I don't know how easy it would be to figure out (probably not very) - but it seems like at least a handful of times a year, there's an iNaturalist observation from Southeast Alaska (which is where I most pay attention) of a non-marine arthropod that's not previously been reported in the state.

Regarding footnote 3 - in 2017 we did a Community Big Year in Sitka, and I think that probably explains a big part of the big jump. (@damontighe's visit to the state contributed as well). What it might not explain quite as well is why that jump was sustained and extended. Several of the active Sitka observers continued to post observations, though I think at lower rates, but clearly that was more than made up for by the overall growth in observers/observations in the state.

I'll look forward to your next installment, thanks!

Posted by gwark 12 months ago (Flag)

wow - super cool, muir! cheers to you and the many other Alaskan naturalists who contributed

Posted by loarie 12 months ago (Flag)

Great write-up and it was very interesting to read; thanks for sharing it with the community!
Concerning the non-marine arthropod numbers for iNat in Alaska, I am curious how that compares to some of the other US states. I imagine the reasons why a smaller percentage have been recorded are similar to elsewhere in the world -- they're typically seen as less charismatic, they're smaller and thus more easily overlooked, and there are probably more difficulties identifying species than is the case with larger fauna. Even if I don't have any answers, I appreciate having the questions to mull over. :)

Posted by whaichi 12 months ago (Flag)

That's great, @muir! Thank you for sharing. Your February screenshot is super lucky, since those numbers are cached for a period of time and it's rare to catch so many zeros in a row :-)

Based on watching numbers from the City Nature Challenge projects over time, I'd guess that the decline in species was due to cleanup of some erroneous, out of range identifications from computer vision suggestions and marking more observations as captive/cultivated that weren't initially.

Still missing you all here in DC, and still looking forward to hopefully visiting Alaska for the first time in 2021!

Posted by carrieseltzer 12 months ago (Flag)

Wonderful! What a great piece of work, @muir . Inspires me to do the same for my county projects.

Peggy (@tui ) and I have tickets for a late May trip to Juneau...but we don't know if that will happen. We'll likely reschedule, and when there I will lichenize my heart out!

Posted by gyrrlfalcon 12 months ago (Flag)

This is awesome, thanks for putting this together!

Posted by awenninger 12 months ago (Flag)

Impressive! digging in to different regions of AK, it is really amazing that the area around Sitka has >40,000 observations! @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. I'd be curious to know about the extent that specialized equipment gets used by some of the super observers in Alaska (camera traps, moth lights, macro photography etc) as it seems like addition of some of these tools might really help this great growth, especially in new species documented. Well done Alaska!

Posted by damontighe 12 months ago (Flag)

Perhaps of interest: @paul_norwood 's observation of Aspidotis densa turned out to be, as he surmised, a range extension of the species into Alaska, first documented here.

Posted by choess 12 months ago (Flag)

@damontighe - two or three of us in Sitka have been keeping track of moths at lights (@kilasiak and I at least using UV lights on our porches).

@swiseeagle regularly posts moths (including new state records, from time to time) from Wrangell, but I'm not sure if she has a UV light set up.

I've seen @swiseeagle, @paul_norwood, and @kilasiak post observations with photos of microscope views (have done so a couple of times myself, as well).

@kljinsitka is a frequent visitor to the beaches around Sitka throughout the year, using a head lamp during the low tides that happen after dark in the winter - in addition, she spends time commercial fishing, and getting observations of interesting deep-sea organisms that come up on gear (or in the stomachs of fish).

@mckittre is also a frequenter of low tides on the Kenai Peninsula (and incidentally posted an observation Pholis shultzii which may be the first record from Alaska: ).

In recent months @sitkaconnor has branched out beyond his bird focus (his LeConte's Sparrow observation was a new state record: ) and has taken what he learned from @paul_norwood about finding marine creatures on lines hanging down in the harbors to start documenting more marine creatures (including some very small nudibranchs).

I often take macro photos (sometimes with an assist from @sitkarowan who has sharper eyes than I do, and can find impressively small creatures without an assist from magnifying lenses of any sort).

I've not seen many camera trap pictures in the Alaskan areas I keep track of (I do have a trail cam, but usually do video, and haven't posted observations from it).

Posted by gwark 12 months ago (Flag)

I would love to add some interesting flies to the iNat Alaska checklist. I hope we'll be able to travel next year. Fingers crossed.

Posted by treegrow 12 months ago (Flag)

Thanks for pulling this together! I am envious of all of you in Sitka -- I'd love to have that kind of community in Kachemak Bay. There are lots of local people observing stuff -- just not organized onto any particular platform. I'm unlikely to ever get over my low tide fascination (and there's still so much to learn), but maybe this summer I'll start working on adding more different types of organisms here.

Posted by mckittre 12 months ago (Flag)

Nice job gathering the information together. Thanks.

Posted by connietaylor 12 months ago (Flag)

As soon as the COVID thing becomes a background endemic and travel is okay again, anyone traveling to AK is welcome to swing through Sitka! We've been known to help people find stuff, too so give us a heads-up...

Posted by paul_norwood 12 months ago (Flag)

Thanks all for the positive feedback. Part II on variation across AK boroughs also posted:

Posted by muir 12 months ago (Flag)

That's a wonderful summary of the state's natural world and the naturalists who are observing nature. I know a bit about the challenges of dealing with data manually, on the other hand, I often make serendipitous discoveries by working through the data methodically at an observation level. Glad I took your advice and started with part 1!

Posted by brewbooks 12 months ago (Flag)

@gyrrlfalcon best of luck on your trip. Following your comment, I found a state lichen checklist (, so I added a lichen section for you above. (If I had known beforehand how messily lichen fit into their taxonomic families, I might not have attempted it!). Around a quarter of the checklist total has been recorded by AK iNat'rs so there's lots of fun ahead of you and tui. If you end up rescheduling, perhaps you would be interested in adding on a fungus festival?

I found a moss and liverwort checklist in the same spot, so I added those too. Anybody know of other state checklists that I missed, and that aren't included within the checklists listed above?

I think I'm going to mangle the framing of this, but if.... (a) AK iNat has identified around ~3,320 unique taxa on the known checklists (birds, fish, liverworts, etc), and (b) the current total of unique taxa identified by AK iNaturalist is ~5,080.... then that means about ~1,750 unique taxa are remaining that aren't covered by the existing checklists. Does that seem about right to people? That we've collectively posted almost 2,000 unique taxa of marine arthropods and o/ invertebrates, non-lichenized fungi, seaweeds, etc?

Posted by muir 12 months ago (Flag)

@muir - thanks for adding the other taxonomic groups! For what it's worth, I've seen a Southeast Alaska preliminary checklist that has over 200 species of liverworts, so I'm not sure how they came up with the number on the site you referenced, but seems very low to me. Mosses seems like it could be closer.

I suspect the lichen checklist is an under count as well. @toby_spribille may be able to say more - he was part of a couple of inventories in Southeast Alaska national parks which I think probably had well over 700 species between them. (see and )

@hfb might know of (or know someone who has) a checklist of seaweeds for Alaska. There's a book on Seaweeds of Alaska, but it isn't comprehensive.

There are a bunch of fungi and marine invertebrates with many observations on iNaturalist. I wouldn't be surprised if a significant chunk of the nearly 2000 species that didn't show up in one of the checklists are in those groups (for example, there are 260 molluscs).

I'm not aware of any full checklists, but there are probably some regional checklists that might suggest an order of magnitude at least (@kmohatt or @kilasiak might know if there are).

@aaronbaldwin may be aware of some checklists for marine invertebrates, and/or be able to give at least some lower bounds for number of species in those groups.

Posted by gwark 12 months ago (Flag)

@muir Lichen taxonomy is ever-changing, from what I have observed so far. Thanks for the link to the Alaska checklist - that's daunting!

Posted by gyrrlfalcon 12 months ago (Flag)

@gwark thanks so much for the links, tags, and everything that y'all have done in Sitka. Echoing mckittre, I am envious!

Regarding new species that are state records (as well as being new-to-iNat) that you and @choess are talking about, I think the best way to collate those is with a dedicated project. If I'm remembering correctly, the iNat Places webpages used to have more functionality around adding checklists (and would display something like "X" species observed out of "Y" species total), but I don't think it was a popular feature, or it was a drag on loading speed, or some other reason why checklists aren't really emphasized now. @loarie might be able to share the history there. Whenever I notice it, and no matter how many times the specialists tell me that it's not really that impressive, I still like to add a comment when an observation is of a species or genus that hasn't been identified on iNat for a place yet.

@whaichi I wonder how the Alaska %s compare to other US states too, but the data may not be complete enough for comparisons to be very meaningful. On one hand, I'm guessing that the broad overall pattern of taxonomic groups & observer behavior is the same in Alaska as elsewhere: iNat coverage is best for bird checklists, followed by vascular plants and mammals (and herps where relevant) in the upper middle, with fish and inverts in the lower tiers. But I think valid comparisons between states really depend on the completeness of the checklist (or at least checklists of comparable completeness?). And I don't know how the perceived completeness of the AK checklist for non-marine arthropods compares with other states (maybe @awenninger @mbowser @dssikes would be willing to share an opinion?). One stat that sticks out to me from a state moth checklist published in 2012 was that the list probably only represented half of the species that actually occur in Alaska because of various challenges of collecting in the state, etc.

@carrieseltzer good luck in the upcoming nature challenge! I think that might be right on the main cause of the fluctuations -- errors related to out-of-range IDs suggested by computer vision, with other revisions due to captive/cultivated, etc, thrown in. @treegrow the flies will be waiting for you.

@paul_norwood looking forward to one day taking you up on the offer!

Posted by muir 12 months ago (Flag)

@gwark a large new paper on SE Alaskan lichens will be out in a matter of days. The cumulative number is much larger

Posted by toby_spribille 12 months ago (Flag)

@toby_spribille that sounds really interesting - I would be interested finding out how to get it once it's available. Thanks!

Posted by gwark 11 months ago (Flag)

yep. same here.

Posted by paul_norwood 11 months ago (Flag)

It will be online in the journal The Lichenologist on May 11. Watch for updates. There will also be a press release.

Posted by toby_spribille 11 months ago (Flag)

@muir - following up on the other taxa - I rediscovered a checklist of Marine Macroinvertebrates published in 2016: They include 3700 species (table 1 has counts by larger taxonomic groups).

Posted by gwark 10 months ago (Flag)

@muir @gwark and others, the Glacier Bay paper is now out:

We also have a catalog of Alaska lichens 99% finished and set to print this year

Posted by toby_spribille 10 months ago (Flag)

Congrats Toby. I'll look forward to reading, but the comment from the abstract jumps out: "The lichen inventory from Glacier Bay National Park represents the second largest number of lichens and associated fungi documented from an area of comparable size and the largest to date in North America."

Excellent find on the NOAA report, gwark. Rather than keep updating this journal entry, I think I should create another journal post with a simple table to collect links, etc.

Posted by muir 10 months ago (Flag)

Catalog of Alaska lichens! I'm intimidated and impressed!

Posted by gyrrlfalcon 10 months ago (Flag)

New goal this fall: to find Carneothele sphagnicola. In the meantime: for sure I've been overlooking Spilonema maritimum for a while now. Thanks @toby_spribille ! Tell us when the catalog is out. Even the list at the end of this paper will be very useful.

Posted by paul_norwood 10 months ago (Flag)

Today (Oct 15, 2020), the 150,000th iNat observation in Alaska was posted, approximately 13 months (Sept 8, 2019) after breaching 100k. Since 5k unique taxa was recorded on March 10, over 700 new unique taxa have been added. Current totals = 5,723 unique taxa, 4,642 identifiers, 5,296 observers.

I believe the observation that broke the 150k barrier today was this lingonberry posted by @pynklynx

Posted by muir 6 months ago (Flag)


Posted by jasonrgrant 3 months ago (Flag)

Thanks @jasonrgrant. Let me know if you have any feedback on the plant summary, or if the numbers or interpretation feel "off" somehow.

Posted by muir 3 months ago (Flag)

Another mini-milestone breached: 5,000+ people have now identified an observation in Alaska. The current (2/25/21) topline stats: 162,003 observations, 5,873 species, 5,004 identifiers, 5,507 observers.

Looking at some other NW and western states, Alaska's general parity between iNat identifiers and observers seems more unusual than not. The norm appears to be 1.5-3x more observers than identifiers. Having about the same (or fewer) observers compared to identifiers seems to be more common in western small population states like Alaska and the Dakotas.

Posted by muir about 2 months ago (Flag)

That's interesting @muir - I imagine population is likely the main factor, but I might also wonder about the proportion of bird and (charismatic megafauna) mammal observations (which may be correlated with population - though it's not obvious to me that it should be). Based on my impressions going through all the observations from south coastal Alaska, my impression is those groups attract a much broader set of identifiers than other groups, and Alaska has a lot of observations of things like marine mammals, large terrestrial mammals, and birds relative to plants and other organisms.

Another factor could be the proportion of observations made by tourists (which would also tend to be weighted toward charismatic species, I would think). Smaller population states might be expected to have a higher proportion of observations by visitors, I suppose.

Just thinking out loud (so to speak) about plausible explanations - I have no idea if they are true or not!

Posted by gwark about 2 months ago (Flag)

Add a Comment

Sign In or Sign Up to add comments