April 28, 2016

It's Mustard Week on iNaturalist! Apr 24 - Apr 30, 2016


If you’ve ever “eaten your greens,” odds are you’ve consumed members of the Brassicaceae, or Mustard family, of plants, which is what we’re looking for during this week of the Critter Calendar!

A huge family comprised of over 3,000 species, mustards contain some of the most economically important plants in the world. Many are eaten as food, such as Brassica oleracea, a species which has been cultivated into forms as diverse as broccoli, collard greens, cabbage and kale; and many are considered weeds in areas where they have been introduced, such as Black mustard.


A clue to help you identify mustard plants comes Cruciferae, an old name for the family. Cruciferae means “cross-bearing,” and refers to the shape of mustard flowers, which have four petals in an x-shaped pattern. Mustard flowers also have six stamens, four of which are long and arranged in a cross-like pattern, and four sepals. They are usually yellow, lavender or white in color.

Mustards also:


  • Are herbaceous (lacking woody stems), except for several genera in the Mediterranean like Zilla spinosa

  • Have leaves which are alternately- arranged (for the most part), meaning the leaves are not across from each other on the stem. Sometimes the leaves form rosettes around the base of the plants, which are circular and the leaves are all at a similar height.

  • Form fruits called siliquae. These are long and resemble legumes. They separate into two or four segments when mature. Fruits less than three times long as they are wide are referred to as silicles.

  • Often grown in disturbed areas

  • Are the host plant for “cabbageworm” butterfly larvae, such as the Cabbage White butterfly.

Some mustard plants you might see are rockcress, dyer’s woad, peppergrass, and wild radish, among the many many species of mustard plants.

We’ll be keeping track of your sightings here. Happy mustard hunting!

Posted on April 28, 2016 08:54 PM by loarie loarie | 0 comments | Leave a comment

April 27, 2016

Observation of the Week 4/27/16

This pair of Lesser Flying Squid seen by aunty and photographed by Robert Atkinson off the Kermadec Islands is the Observation of the Week.

The Kermadec Islands are a remote archipelago about 800 km northeast of New Zealand’s North Island, and last year they became part of the newly-declared Kermadec Ocean Sanctuary, a 620,000 square km area protected by New Zealand. Katy Johns (@aunty on iNat) was lucky enough to go on an expedition there last month by Forest and Bird, an independent conservation organization in New Zealand, “as part of a campaign to bring attention to the area,” says Katy. “The sanctuary will protect a significant portion of the world’s longest underwater volcanic chain and the world’s second deepest ocean trench.”

It was during this expedition that she and others witnessed the surreal sight of squid taking to the air. According to Katy, “They didn't fly very high above the sea - maybe a foot or so for about 10 yards,” but “it was quite a magical sight as twenty or more would all jump out together.” The picture above was taken by photographer Robert Atkinson, from whom she obtained permission to use it for her iNat observation.

Very few details about Lesser flying squid can be found online, and I couldn’t come up with anything regarding their “flying” behavior, aside from the fact they are the only known flying mollusk (thank you, @invertzoo!). The species ranges widely throughout the Atlantic and Indian Oceans, and out to the east of Australia and New Zealand, and averages between 13-22 cm in length.

As for Katy, a background in botany and a lifelong interest in nature has lead to her being the secretary of a local hiking club. She describes herself as a “keen iNaturalist contributor” and “[I] always take my camera with me these days as I travel in my job and often get to take a walk in a new area during the day.” Creating and sharing observations during her travels has “helped me to learn about environments all over the world. I think it's a fantastic resource for all kinds of research and education.”

- by Tony Iwane


- both Katy and I have reached out to Robert Atkinson about his photo and his thoughts on the squid sighting but haven’t heard back. I’ll update this post if and when he replies.

- Two quick encounters with flying squid captured on video (thank you GoPro!).

- Is some calamari actually pig intestine? A classic This American Life episode investigates...

Posted on April 27, 2016 09:38 PM by tiwane tiwane | 2 comments | Leave a comment

April 21, 2016

It's Lizard Week on iNaturalist! Apr 17 - Apr 23, 2016


This week the Critter Calendar we’re focuses on a charismatic group of reptiles who have an almost worldwide distribution and inhabit most terrestrial ecosystems on Earth - the lizards! There are several taxonomic definitions of lizards, and for the purposes of the Critter Calendar we are focusing on a fairly traditional view, which includes what’s in the suborder Sauria on iNaturalist. You can check out our Sauria page to see which families are included on the left-hand side.


So just what is a lizard? For the most part we all know one when we see one, but some can be tricky and as lizards are an evolutionary grade, they are often defined negatively, through differences between close lizard relatives like snakes and the tuatara.



  • Lizards, like all reptiles, have scaly dry skin. Lizard scales can take on many forms - some are granular and pebbly, some are smooth and plate-like, while others are spiny and overlapping. Many lizard species will have several types of scales, such as the Night Lizards, who have large plate-like scales on their head and tiny granular scales over the rest of their bodies.


  • Most lizards have eyelids and external ear openings, which snakes lack.
    Most lizards have four limbs. Some, however, have only vestigial limbs and others such as the Glass Lizard are completely limbless.


  • Many lizards can “drop” their tails when threatened. Snakes are not able to do this.
    Unlike snakes, the internal organs of lizards are not linearly arranged. Lizards also have two functional lungs - snakes have only one functional lung.


  • The Tuataras of New Zealand has a slightly different skull than lizards do, and are the only extant members of the order Rhynchocephalia.

Some familiar and/or interesting types of lizards are:


Monitor Lizards (Family Varanus) - An ancient family found in Asia, Africa and Australia, these lizards have a triangular-shaped head, forked tongues, long necks and powerful legs and tails. The world’s most massive lizard, the Komodo Dragon, belongs to this family.




Geckos (Infraorder Gekkota) - Named for the chirping sounds they make, Geckos are mostly nocturnal and most geckos have incredible adhesive feet which allow them to climb on many surfaces. The majority of geckos also lack eyelids and must clean the transparent membrane over their eyes by licking it.




Chameleons (Family Chameleonidae) - a bizarre group of Old World lizards with zygodactylus feet, long extendable tongues, and eyes which can move independently of each other. Many are able to change their skin’s color but this is done more for communication and not for camouflage.




Skinks (Family Scinidae) - lizards with long bodies, no pronounced neck, and short or nonexistent legs. Most skinks are adapted to moving quickly along the ground, almost like a snake, but some, such as the endangered Solomon Island Skink, live arboreally. This species even lives in social groups called circuli.


If you see a lizard this week, Share your findings with us on iNaturalist, we’ll be keeping track here. Happy lizard hunting!

Posted on April 21, 2016 05:42 AM by loarie loarie | 6 comments | Leave a comment

April 20, 2016

Observation of the Week, 4/20/16

This Anyphaena spider seen by leptonia in Santa Cruz, California is our Observation of the Week!

Sure it’s a pretty enough spider, but it’s the story behind this find that made me choose it for Observation of the Week. And as a bonus it involves two field guide authors! (Thank you to @anudibranchmom for bringing this observation to my attention)

“I found this in my housemate's sister's ear,” writes Christian Schwarz (@leptonia) in the notes for this observation. Great writer that he is, I’ll let Christian finish the story in his own words:

She reported sensations of "extreme tickling" inside her right ear and said "I think I have a spider in my ear". When she turned her head, I was surprised at how immediately her suspicions were confirmed - as evidenced by a set of spider's legs emerging from the bowl-shaped depression at the bottom of her ear.

I inserted the tip of my pinky finger into her ear canal to prevent the spider's escape inwards. I then flushed it out of her ear with my other hand.

I caught it after it fell to the floor and moved it to a wall outside where it remained motionless for 15 minutes.

For the arachnophobes out there, thanks for making it this far! While this situation is not unheard of, it’s rare, so it’s probably not something to add to your list of concerns. Oh, and those stories of spiders laying eggs in people’s skin, or the “fun fact” that humans swallow spiders while we sleep are just that - stories. As anyone who’s encountered a spider knows, they want as little to do with us as possible.

This spider was identified as a member of the Anyphaena genus (in the “ghost spider” family Anyphaenidae) by R.J. Adams (@rjadams55), author of Field Guide to the Spiders of California and the Pacific Coast States and a great contributor to the iNat community. He tells me that the tracheal spiracle (where they breathe) of ghost spiders is located much further towards the middle of the body than other spiders, which “is likely related to their exceptionally vigorous courtship. While in many families, the wooing of a mate is a cautious and deliberate affair, but in the world of ghost spiders, it involves rapid dances and abdominal vibrations at blurring speeds.” They are harmless to humans.

Identifying a spider down to genus and species levels is often “extremely difficult” (it usually involves looking at their reproductive organs under a microscope), but R.J. says that to help narrow the field, get a close, sharp photo, especially of the eye arrangement, and “also extremely helpful would be a photo or description of the web and the habitat where it was found, whether it was crawling across a suburban backyard, in the leaves of an oak tree, running across a sandy beach, or in this particular case, in a friend's ear. :-)”

I mentioned this observation involved two authors, and of course Christian is the other one. His specialty is not spiders, however, but fungus. “My brother's love of JRR Tolkien (and his many references to mushrooms) led to my interest fungal taxonomy,” he says, “which is where the focus of my natural history interest has been anchored for ten years.” Mushrooms of the Redwood Coast, which Christian co-authored with Noah Siegel, is set to be published on August 9th, and Christian is also busy doing a botanical survey in Santa Cruz and continuing his “Sisyphean task of compiling a Santa Cruz Mycoflora [and] preparing for an IUCN meeting in Oregon at the end of the month.”  Here's an example of the kinds of proposals they’re writing.

Christian has incorporated iNaturalist into his Santa Cruz Mycoflora project, his botanical surveys, and his own personal explorations. He says that using iNaturalist has caused him to think more about the spatial distribution of organisms and about the total diversity of life “because I feel confident that for most any critter I encounter, there will be someone in the iNat community will be able to help me learn its name (at least approximately) or something about its ecology...It took me a while to get used to the platform, but now it's a central part of my natural history practice.”

- by Tony Iwane


- Christian also leads nature tours in the Santa Cruz area through his Redwood Coast Tours - if you’re in the area check it out!

- R.J. is trying to observe 250 species in each of California’s 58 counties - quite a quest! You can follow along in his iNat journal.

- A computer animator made this pretty convincing video of a spider crawling out of someone’s ear. 

- I couldn’t find footage of ghost spider courtship, but hey, Peacock Spider courtship dancing is pretty awesome. 

Posted on April 20, 2016 03:51 PM by tiwane tiwane | 1 comments | Leave a comment

April 15, 2016

Observation of the Week, 4/15/16

A traffic-stopping herd of Reindeer seen in Norway by alessandro_gentilini is our Observation of the Week!

While on a road trip in Scandinavia with his girlfriend Susy, Alessandro Gentilini had several memorable encounters with Reindeer. In Finland, he says, “the road we were traveling became deserted and we were the only car around. It was like an airport runway. A reindeer stood there quietly looking at us. I realized that this really was a Finnish highway.” The photo above, however, was taken in Norway, as Alessandro and Susy were returning from the North Cape. While driving along the road they had to stop at the exit to a tunnel, as the way was blocked by a herd Reindeer! Susy, “who always had a camera ready,” took the above photo of them, capturing the very surreal scene. Alessandro hypothesizes that maybe the tunnel walls were a source of minerals for the animals, and “licking the tunnel walls is perhaps an easy way for them to get these nutrients... but I’m not a naturalist and so I may be mistaken!’

Reindeer is the name for Eurasian populations of Rangifer tarandus, known as Caribou in North America. These large cervids have several really cool adaptations which help them survive the punishing winters of the Arctic regions. Their noses and respiratory system, for instance, are shaped in such a way that cold air is warmed and moistened before going to the lungs. And in the depths of winter, Reindeer eat lichen (especially Reindeer lichen) and are the only mammals in the world who eat lichen. The enzyme lichenase helps them convert the lichen to sugars and, aside from some gastropods, no other animals have this enzyme. Also, you’ll notice that all the Reindeer in this photo have antlers - this is the only deer species in which both males and females grow them.

As a child, Alessandro “was not very interested in nature,” even when exploring the mountains with his parents. But an interest in photography and summer vacations in the Dolomites when he was in his twenties helped him develop an interest in the natural world, and he says that now with his photography “what interests me most is documenting nature.”

Alessandro is now part of a growing contingent of iNaturalist users in Italy, and he uses iNaturalist “as a journal or log where I record animals I see,” including the only observation of Chirocephalus marchesonii, a species of fairy shrimp endemic to Lago di Pilato (see above), on iNaturalist. Alessandro says “using iNaturalist certainly influences my interactions with nature,” so much so that even the roadkill he sees while he rides his bike now makes him ponder. “I'd rather see it alive but then I think ‘At least, I could put this picture to put on iNaturalist..’”

- by Tony Iwane


- Here’s a video about Reindeer featuring California Academy of Sciences’ own Dr. Jack Dumbacher.

- Humans have been interacting with reindeer for probably 45,000 years, at least. This page has some info about reindeer hunting, herding, and more.

- There is no documented evidence of reindeer flying or pulling any sleigh belonging to a jolly old elf.

Posted on April 15, 2016 08:07 AM by tiwane tiwane | 0 comments | Leave a comment

April 12, 2016

It's Tree Frog Week on iNaturalist! Apr 10 - Apr 17, 2016


The Critter Calendar makes a return to the world of, well, critters - it’s Tree Frog Week!

The Hylidae family of frogs is often known as “tree frogs and their allies” because of its large diversity, which includes many of what we traditionally think of as tree frogs, like the iconic Red-eyed Tree Frog, as well as frogs which don’t live arboreal lives at all. There are about 900 species in the family and they are found throughout much of the world, excepting sub-Saharan Africa and northern Eurasia. Many species are concentrated in the Americas and in Australia and Oceania.


Characteristic traits of those hylids adapted to an arboreal life are large feet with sticky toe pads and forward-facing eyes which give them enhanced depth perception. Unlike geckos, whose toe pads use a form of “dry” molecular adhesion, hylid toe pads have microscopic hexagonal cells which create friction with a surface, and grooves between the cells which allow for the flow of mucus, also aiding with adhesion. Most hylids are green or brown in coloration, with various markings, and have powerful legs for jumping.



Hylinae - this large subfamily has a wide distribution and includes the European Tree Frog, which is found throughout Europe, northern Africa, and temperate parts of Asia east to Japan. Other notable members include the Spring Peeper, which is found in eastern North America, and the Brazilian Heart-tongued Frogs, which live and breed in bromeliads. The tadpole of the Paradoxical Frog grows huge (up to 10” long!) but morphs into an adult that is perhaps one quarter of that size. This subfamily is also home to the world’s only known venomous frogs, described last year.


Phyllomedusinae - the “leaf frogs,” which are found in Central and South America. Many species of this small subfamily, like the Waxy Monkey Frog, lay their eggs not in water but on leaves which hang over water. When the tadpoles hatch they fall into the water and live as filter feeders. The adults, then, never have to return to the ground to breed. The Gliding Tree Frog uses its webbed feet to glide while jumping between branches.



Pelodryadinae - the Austro-Papuan tree frogs. Found in Oceania, there are over 160 species in this subfamily. The Australian Green Tree Frog (aka White’s Tree Frog) is commonly found around dwellings and is commonly sold in the pet trade. They are members of the genus Litoria, which are distinguished by having horizontal irises. This subfamily also includes the Cyclorana genus of burrowing frogs, which are completely terrestrial. These frogs live in dry areas, remaining dormant underground for up to five years until big rains bring them to the surface. They lack toe pads.


Look and listen for hylids this week, but remember that frogs are fragile creatures and handling them can be harmful to their health. Share your findings with us on iNaturalist, we’ll be keeping track here. Happy tree frog hunting!

Posted on April 12, 2016 06:56 AM by loarie loarie | 6 comments | Leave a comment

April 07, 2016

Observation of the Week, 4/7/2016

This Dendronotus orientalis nudibranch seen by anudibranchmom in Redwood City, California, is our Observation of the Week!

Robin Agarwal (anudibranchmom) is currently travelling and wasn’t able to write us back by publication time, so we have two awesome iNatters chiming in on this find. We’ll post an updated version once we hear back from Robin.

One of iNaturalist’s most prolific users (12,000+ observations!), Robin Agarwal got into nudibranchs due to her daughter’s interest in marine biology, and has quickly branched out into observing many forms of life. But her experience with nudibranchs of the San Francisco Bay Area caused one to catch her eye, as she was unfamiliar with it. She posted photos of it on iNaturalist and Alison Young (@kestrel) the California Academy of Sciences Citizen Science Engagement Coordinator, was able to identify it as Dendronotus orientalis, a species originating in Asia and, as far as we can tell, never before documented in the U.S.! Rebecca Johnson (@rebeccafay), a marine biologist and Citizen Science Lead at the Cal Academy, asked nudibranch expert Terry Gosliner to confirm the ID, and marine invertebrate expert Gary McDonald (@mcduck) also agreed. “This was a truly community effort,” says Rebecca, “and for me, the coolest thing is that the correspondence that would have been normally limited to ‘expert’ emails and hidden is now done in public!”

One of the most active and encouraging members of the iNaturalist community is Susan Hewitt (@invertzoo), a “serious amateur” malacologist, who tells me that nudibranchs are a diverse group of sea slugs, “although the name ‘slug’ hardly does them justice! Many people who are familiar with them feel that nudibranchs are the most beautiful organisms on Earth, their colors and forms rivaling or exceeding even those of butterflies.” Not much is known about this particular species, but Susan points out its most distinguishing feature, which is that the sheaths of its rhinophores (chemoreceptive structures protruding from the body) extend to well past the body length of the animal. And like many other nudibranchs this species eats hydrozoans, tiny predatory (and often colonial) animals related to jellyfish and corals. Some nudibranchs even sequester the stinging cells of hydroids and use them for self-defense!

Dendronotus orientalis

Due to San Francisco Bay’s use as a major shipping port, “more and more species of marine invertebrates were accidentally introduced,” says Susan, “and a large number of them found habitat to their liking, and flourished there.” Rebecca Johnson took a team to collect some of the Dendronotus orientalis that Robin found, for further study, and says “early detection of invasive species is critical for the protection of the San Francisco Bay, [and] thanks to dedicated naturalists like Robin, and the iNat platform, we can learn more about changes in the bay and beyond more rapidly than ever before - and that information can be shared with a bigger community more quickly - so we 'know' when something is really important.”

- by Tony Iwane


- You can check out more of Robin’s awesome photography on Flickr. She also took a video of the nudibranch!

- Susan Hewitt has a great guide to photographing mollusks on her profile page, and she also appears in a video on Wikipedia about “love darts.” Check it out!

- The California Academy of Sciences team took a video crew with them when collecting their specimens, and we’ll post the video on our Facebook and Twitter pages when it’s finished, so follow us there!

Posted on April 07, 2016 11:16 PM by tiwane tiwane | 0 comments | Leave a comment

April 05, 2016

It's Legume Week on iNaturalist! Apr 3 - 9, 2016


One of the most economically important families of plants, the Pea Family (Fabaceae) is used by humans mostly for its fruits, but this huge family of over 18,000 described species boasts beautiful flowers and wonderful compound leaves as well. We’re featuring this family on the Critter Calendar this week, so let’s dive in and learn what makes it special!


We’re all familiar with a pea pod or bean pod, and this type of fruiting body is called a legume, which is typical of the Fabaceae. A legume is a dry (as opposed to fleshy) fruit which dehisces (opens) along a seam, usually on two sides. Legumes come in many forms, and are long and skinny, as in the acacias, while others are shorter and stouter, like those of a lupine. Peanuts, which are not nuts at all, are legumes that develop underground - a rare trait called geocarpy.

Most Fabaceae leaves are alternate (not opposite each other on the stem) and pinnately compound (meaning there are many leaflets on the petiole, or leaf stalk). Fascinatingly, compound leaves of the Sensitive Plant (Mimosa pudica) fold inward when touched. At the base of each petiole is a stipule, or growth, that can come in the form of a thorn or a leaf-like shape as in the Garden Pea.

The three subfamilies of the Fabaceae have quite different flowers. Flowers of the Mimosoideae subfamily have enormous stamens and tiny petals often in a spherical shape - kind of like a pom-pom. Faboideae subfamily flowers are Papilionaceous, meaning butterfly-shaped - a large petal on top folds into two smaller petals, with two other small petals forming the bottom of the flower. Overall they are somewhat concave and are bilaterally symmetrical, like the human face. And finally the flowers of the Caesalpinioideae subfamily are also bilaterally symmetrical but the petals are usually all the same shape and the flower is more “open” than concave.

Plants in the Pea Family are found nearly everywhere on Earth, so there’s probably one near you! If you think you see any of these this week, share your observations with us. We’ll be keeping track here. Happy Fabaceae hunting!

Posted on April 05, 2016 07:02 AM by loarie loarie | 2 comments | Leave a comment

April 01, 2016

Observation of the Week, 4/1/16

This Merismopedia colony seen by sarka in Florida is our Observation of the Week!

Most observations posted to iNaturalist are of macroscopic life - organisms one can see with the naked eye. Much of life on Earth, however, is microscopic, and we’re lucky enough to have some users who specialize in photographing these exquisite tiny organisms, folks like Sarka Martinez.

When she was a professional with a degree in computer science, Sarka always felt that computer science “was a world that was not really me. I needed to be outside delving into the natural world, a world of discovery and research.” After “retiring,” she now has the opportunity to do things that really interest her - like documenting seaweed, diatoms and other types of plankton in both Washington State and Florida! “I must say that looking at all life in the water is my very best hobby,” she says. “Looking at pollen is pretty awesome too.”

Sarka had her first opportunity to work with “fancy” microscopes while volunteering at the Whitney Marine Laboratory in Florida, documenting seaweeds and looking at their cell structures to get her identifications down to species level. She now documents plankton for SoundToxins.org in Washington for six months of the year, and for NOAA in Florida for the rest of the year.

The Merismopedia colony she found in Florida is a type of cyanobacteria, also known as blue-green algae. Ancient organisms, tiny but mighty cyanobacteria are photosynthetic and are believed to have been the cause of the The Great Oxygenation Event 2.3 billion years ago, creating oxygen that accumulated in the atmosphere. Merismopedia is a genus of cyanobacteria, and they divide in only two directions, forming a characteristic grid pattern. Merismopedia can move using filaments called hormogonia.

So how to photograph such a tiny thing? Sarka uses a simple set-up consisting of a used Leitz Laborlux S microscope (bought on eBay) and a cheap Celestron camera that connects to her computer via USB. “Out of 100 images,” she says, “I keep about 20 that turns out to be around 5 organisms.”

“Part of taking photos is to have people tell me if I am identifying them correctly. iNaturalist is a great vehicle to do that and is a great place to store my photos,” says Sarka. She and her husband also use iNaturalist as a motivator to explore new places. “We treat our trips like scavenger hunts, hoping to get an amazing find or to be the first to ‘find’ in the region.”

- by Tony Iwane


- Sarka has two plankton projects on iNaturalist: one for the southeastern US, and one for the Pacific Northwest.

- There is, of course, a Merismopedia video on Youtube. The colony begins to flip around at about 3:17, which is pretty neat to watch.

Posted on April 01, 2016 09:59 PM by tiwane tiwane | 0 comments | Leave a comment

March 28, 2016

It's Carrot Week on iNaturalist! Mar 27 - Apr 2, 2016

Breathe in the pungent aromas of the Carrot family (Apiaceae) for the Critter Calendar this week! With over 3,700 species, this huge family of plants include many commonly used vegetables and seasonings, including carrots, coriander, celery, dill, cumin, anise and more. However, some species such as poison hemlock contain powerful toxins, so please don’t ingest any unless you know exactly which plant it is.

The Apiaceae are also known as the Umbelliferae, and that latter name is taken from their distinctive inflorescence (flower cluster), which is known as an umbel. Umbels are made up of many stalks originating from a stem which resemble the ribs of an umbrella. Some umbels have an almost flat top, as in sweet fennel, while others are arranged in a more spherical shape. Apiaceae flowers have five sepals, five petals, and five stamens, and are often small.

Other general characteristics of Apiaceae:

  • Mostly herbaceous, meaning they lack woody stems.
  • Stems are often hollow.
  • Leaves are usually alternately arranged, dissected (divided into many deep segments), and pinnatifid (the lobes are not discrete).
  • Crushing the leaves of most Apiaceae plants produces a strong odor.

In addition to its culinary uses by humans, many pollinators use the flowers of the Apiaceae as a source of nectar, and ambush predators like crab spiders can often be found on the umbels if you take a close look.

If you think you see any of these this week, share your observations with us. We’ll be keeping track here. Happy Apiaceae hunting!

Posted on March 28, 2016 03:55 PM by loarie loarie | 10 comments | Leave a comment
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