From left to right, Helminthoglypta nickliniana, Helminthoglypta arrosa, Haplotrema minimum
A little while ago I was talking with my co-worker Rebecca and we were lamenting the fact that so much knowledge about the natural world is locked up in the brains of a few, not because they guard it jealously, but because these tidbits are either too minor and disjointed to be publishable as scientific research, or because they are qualitative, or seem obvious to the experts. What a shame! We felt like every time we had the privilege to go out into the field with these kinds of people, they would reveal amazing facts about the predatory habits of parasitic wasps, or where to find butterflies in the rain, along with wonderful stories about how they came to know these things, but the only way for others to know them would be to find them out for themselves, or walk around with an expert for a few hours.
So we came up with an idea: why not start a biodiversity oral history project to record these facts and stories, along with the voices of the people who told them to us. At a bare minimum, we could start recording these conversations we were having and post them online, but at a resplendently-attired maximum we could publish these recordings alongside written, searchable transcripts, with photos and/or video recorded during these hikes. To give these walks a bit of structure beyond just having conversations, we could organize the projects around making very local field guides, so the ostensible point of the walks would be for the expert to introduce the recorder to the topic of the guide and seek out the organisms in question, and the recorder would record everything the expert said during the walk, take pictures of the organisms they found, do some research based on what they learned, and assemble the guide in collaboration with the expert.
We talked with Heather, the Academy's chief librarian, and she thought it sounded like a good idea and had thoughts about how to host the data and do the transcription, and maybe even fund it, but first we had to try it! I know embarrassingly little about mollusks despite my love of nudibranchs, so I suggested we start with the land snails of San Francisco, and Heather had just the expert in mind: Neil Fahy, retired geologist, avid amateur malacologist, Academy research associate, and longtime San Franciscan.
To start things out, I wanted to follow a model like this:
So, Neil and I set up a meeting at the Academy and talked about snails! He told me he'd deposited his manuscript on Bay Area snails at the Academy, and recommended some other literature for me to check out (which I later did), and we planned a hike to go look for snails. Neil recommended Crystal Springs Reservoir / San Andreas Lake as a decent spot, which is owned by the city of San Francisco, even though it's outside the city limits, so we set a date.
I went through Neil's manuscript and a checklist of SF snails he sent me that was exported from Roth and Sadeghian and used that for the skeleton of the guide using iNaturalist Guides. It became immediately apparent to me that Helminthoglypta was an important and diverse group of native California snails, but they all kind of looked the same, so I was eager to get out in the field and learn about them.
Neil and I met up at San Andreas Lake in Millbrae, I set him up with a recorder, and we started walking. My recording setup was not terribly sophisticated, and the recording shows it! I just took a pair of earbud headphones with an inline mic, paperclipped it to Neil's jacket so the headphones were tucked away and the mic was exposed, and plugged them into a smartphone, which I put in Neil's pocket. I did the same for myself so I could mix together both audio tracks if Neil's didn't capture my side of the conversation (it did a decent enough job). The apps I was using were Voice Recorder Pro on my iPhone and Smart Voice Recorder on an Android phone. I gave Neil the Android phone figuring I would want to use mine for photos and such, but I think that was a mistake b/c the Audio quality ended up being worse, regardless of mic placement. That may have just been the device though, which was a 3+ years old. Also, the paperclip wasn't really the best fastening device. So main technical findings for recording were
Overall I think it went great. We only found 3 snail species, but I learned a ton in the process, particularly about those Helminthoglypta species, which can be separated in the field (H. arrosa is much more common and generally has an open umbilicus, while H. nickliniana usually has a closed umbilicus and has a distinct, regular pattern of oblique ridges on the shell, though you'd need a sharp macro shot or a hand lens to see them).
Of course I also learned a bunch going through my photos and revisiting some of the literature on the species we saw. Pilsbry, for instance, is an amazing resource with a great deal of detail on Californian species, including photos and very detailed locality data.
Reviewing the audio was pretty time-consuming, I have to admit. I was hoping to just upload the file to soundcloud and use it for annotation, but I think that would put me over my free quota, so I turned to Audacity, which isn't quite as nice to look at, but get's the job done for file format conversion, syncing multiple audio tracks, and annotation using label tracks. Pretty amazing open source tool, frankly. The main challenge was that I had 6 hours of audio to review! Audacity makes it easy to skip around to where people are talking, and I made labels for all sections where Neil was talking about snails or something else I found interesting. I've included a few tracks here for you to check out.
01-local-history-of-the-portola-expedition.mp3
02-local-geology.mp3
03-serpentine-land-snails-and-vegetation-preferences-or-lack-thereof.mp3
04-what-drives-snail-distribution.mp3
05-how-to-search-for-snails-shell-decomposition.mp3
06-snakes-kites-humans-and-other-snail-predators.mp3
07-on-studying-newt-development.mp3
08-arboreal-snails.mp3
09-our-first-snail-helminthoglypta-arrosa-how-to-identify-it-how-to-photograph-snails.mp3
10-on-the-caifornia-lancetooth-a-carnivorous-snail-that-eats-other-snails.mp3
11-on-collecting-snails.mp3
12-check-the-bottom-of-slopes-for-shells.mp3
13-how-neil-got-interested-in-snails.mp3
14-on-teaching-kids.mp3
15-bleaching-and-the-effect-of-the-rain.mp3
16-how-to-find-living-snails.mp3
17-finding-a-live-h-arrosa.mp3
18-on-tentacles-nativity-and-preserving-juveniles.mp3
19-on-teaching-students.mp3
20-dietary-preferences-of-h-arrosa-and-haplotrema.mp3
So first of all I need to sit down with Neil again, and look at the remaining species and think about where to find them, and then we need to do so.
I'd also like to peruse the Academy's collections with Neil and photograph some of the species that don't have licensed or public domain photos online. The Academy also has a number of slides of terrestrial mollusks that I'd like to try digitizing.
Also wondering what role journaling should play in this process. I'm taking a few text notes from our discussions, but maybe blogging would be a better, more open way to do that.
In "northern San Mateo county" there are supposedly two species of Helminthoglypta, H. arrosa and H. nickliniana. The former has an open umbilicus (the hole in the middle of the spiral of the shell when viewed from below), while the latter has a flag of the aperture covering the umbilicus. This and many others were found at the bottom of a slope. Coast live oak was the dominant tree.
A living individual found between the bark and wood of a fallen log.
A predatory snail that eats other snails. Its shell is almost flat when viewed from the side, i.e. the spiral doesn't really go up.
Umbilicus fully covered, and I think I can see the reticulated pattern on the shell described by Pilsby: http://babel.hathitrust.org/cgi/pt?id=uc1.31822013176466;view=1up;seq=118
An example of what looks to me like an intermediate Helminthoglypta. From the photos I took it seems like lip of the aperature curves more in H. arrosa, which would suggest arrosa for this one, though the umbilicus seems half covered.
Lots of these around today. Found two logs with a big adult and a small juvenile. Bigger was male under one log, female under another. Coincidence or pattern?
I know I've seen pictures of something like this, just need to hunt them down...
Neil was surprised to find an all-yellow individual this far north. Apparently the position of the air hole with respect to the mantle can be diagnostic, as can the presence of dirt along the tail end.
Living lancetooth, found under a log like all the other living snails we found.
Comentarios
I love this whole idea! Snails were one of my first animal loves as a little kid but I know shamefully little about identifying common species. I applaud you for trying to systematically document some in-depth natural history by downloading it from a naturalist's brain. I look forward to seeing more in the series!
Amazing work!! I admit I don't usually pay attention to snails and slugs even in my own yard (Alligator Lizards help limit their number), but I will start cataloging and try identifying.
Thanks both of you! Yeah, my eyes are really being opened to their diversity, which is actually pretty significant in California, both among natives and introduced species. If you guys do find some snails to photograph, remember to get the three shots I've shown in the pics here: top, bottom, side.
Thanks for the tip! Now that you pointed it out, I see that the side photo really helps distinguish the three species shown here.
In these individuals it definitely did, but I've learned that trait can be a bit variable within Helminthoglypta, at least. Pilsbry's description of H. arrosa is good, and he says "the elevation of the spire varies more than usual." For Haplotrema it totally matters! They're practically flat.
LOVE it.
Totally going to use the question introduced in #14 on my next nature walk when we look for snails.
"Would you rather be a slug or a snail?"
Great entry.
Hey Ken-ichi, I don't know if you've talked to Neil, but be sure to tell him that I did propose that question, "Would you rather be a slug or a snail?" to two groups of kiddos already. One group didn't really think about it too much, even after my prodding, but the other group discussed it quite a bit! It was great!
We flipped over some logs and watched a little Triodopsis sp.. :)
Nice! I'll let him know. I've sort of had this project on hold for a few weeks. Need to make some time for it.
Thanks so much Ken-ichi, your shots are just perfect. This will really help people understand how to image a gastropod shell, making it easier for us to ID them!
Excellent! Inspires me to take a closer look at terrestrial snails.
More power to you Ken-ichi. This is a wonderful project!
Really fun to listen to your recordings. Excited to be learning more about snails and glad to know how to photograph them better. Thanks much!
This seems like a cool series that could be done as a podcast.
It would be, but I basically gave up on it. Processing the audio is a lot of work, and I kind of lost enthusiasm for exploring a city I don't live in. I think it might work as something a bit less ambitious, e.g. just recording a single event with a knowledgeable person and editing that audio into an episode.
Ideas come and go; nice work giving it a try! I bet it comes back in some shape and form!
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