Readers’ wildlife photos

March 13, 2026 • 8:15 am

Abby Thompson, a UC Davis mathematician, is back with more photos (and a video!) from the intertidal of northern California. Abby’s captions and IDs are indented, and you can enlarge her photos by clicking on them.

Jellyfish!

I thought I’d throw some jellyfish into the lull between the great winter tides and the great summer ones.

The reproductive cycles of the tidepool creatures are wildly varied, with behaviors ranging from maternal (see Epiactis prolifera from my last post), chancy (see mussels), through incessant (see nudibranchs).   But for sheer baroque complication, I vote for the jellyfish.    Many who stroll on a beach will see the quivering gelatinous masses of jellyfish stranded by the tide, and the less fortunate will have encountered their stinging tentacles while in the water.  This describes, a little, how they get there.

There are several jellyfish species common on the Northern California beaches; here are some of them:

Aurelia labiata (Greater Moon Jelly):

Chrysaora fuscescens (Pacific sea nettle):

Chrysaora colorata (purple-striped sea nettle) These are big, about a foot across:

Another Chrysaora colorata (handsome creatures):

Genus Aequorea (crystal jelly):

Polyorchis haplus:

Scrippsia pacifica (giant bell jelly):

The Chrysaoras and Aurelia labiata are in the class Scyphozoa; the rest are in the class Hydrozoa.

For all of these, males and females get together in the same vicinity, and release eggs and sperm (see “chancy” above), which form little “planulae”.    Then things get complicated.     Because (usually) the planulae settle down and attach themselves to something, and become polyps.  Like these tiny things:

Genus Sarsia:

Hydrocoryne bodegensis:

But how do they get from here (e.g. something like Sarsia) to there (e.g. something like Polyorchis haplus)?   Well they don’t, always, and sometimes they don’t get from there to here, either, but here’s an illustration of the process when it goes through a “typical” complete cycle:

And in fact if you look closely at that photo of H. bodegensis, you can see a little medusa just budding off, circled in the photo below:

Here’s a video of a set of newly-formed “baby jellyfish” (they look excited) which swam into my microscope view.    I didn’t know what I was seeing, so don’t have a photo of the polyp from which they likely emerged.   This means I have no idea of the genus (or even the class- if these are Scyphozoa then these are really ephyrae which will turn into medusae).

There seem to be many species for which the complete reproductive  process is not documented –  for example, if you search for the polyp stage of Polyorchis haplus, the answer is that we don’t know what it is, nor where it can be found.

 

A final oddity of this elaborate reproductive process is the existence of the so-called “immortal” jellyfish. (not found in the cold waters of Northern California).  If damaged at the medusa phase, this one can revert to its earlier (genetically identical) polyp phase- and so on ad infinitum, apparently.  As though, when things go wrong in your life, you could go back to your childhood and try again.

I’m grateful for help with IDs from experts on inaturalist and elsewhere.    All mistakes are mine.

Readers’ wildlife photos

March 12, 2026 • 8:15 am

And we have more photos. Today’s come from Jan Malik, documenting the birds of Barnegut Inlet in New Jersey. Jan’s captions and IDs are indented, and you can enlarge the photos by clicking on them.

My previous batch from the Barnegat Inlet covered geese and ducks. It’s time for some of the other coastal birds now.

Immature Double-crested Cormorant (Nannopterum auritum). In contrast to diving ducks, these birds have no buoyancy problem and submerge easily.

Common Loon (Gavia immer). Judging by the slightly pinkish gape at the base of its bill and the fuzzy transition between black and white, this is an immature bird that stays on coastal bay waters before maturing and returning to quiet inland lakes to breed:

Another loon, this one with a mangled crustacean that I suspect is an Atlantic blue crab (Callinectes sapidus). I wonder if a diving loon preferentially picks a freshly molted crab the way we select ripe fruit:

Not a great loon picture, but we can see enough of the prey’s fins to identify the fish as an Oyster Toadfish (Opsanus tau), a species in which males provide parental care to eggs and young. The fish was big and bony, so the loon struggled a bit to swallow it. That fish would be a terrible choice for performing the Fish Slapping Dance. For the loon, it would be preferable to swallow its catch underwater, because at the surface it may be stolen by gulls, who know where a bird has dived and circle above waiting for it to reappear:

A couple of Savannah Sparrows were hopping on the rocks. I suspect that this pale bird with very little yellow in its brow is an Ipswich Sparrow, a subspecies (Passerculus sandwichensis princeps) that breeds on the sand spit of Sable Island off Nova Scotia:

Three species of shorebirds are common in winter at the Barnegat Inlet, all quite similar at first glance in size and plumage, but each occupying a different ecological niche. First, the Ruddy Turnstones (Arenaria interpres), here trying to sleep—probably using only one half of their brain to watch for predators, in unihemispheric slow-wave sleep. Their bills are short, stubby, and slightly upturned, adapted for—just as their name suggests—turning over beach debris to search for invertebrates hiding underneath:

Next, the Dunlins (Calidris alpina). They feed, roost, and migrate in large flocks. Unlike Turnstones, their bills are long, slender, and sensitive, used for probing tidal mudflats for worms and crustaceans:

Last, there are the Purple Sandpipers (Calidris maritima). Their bills are more “general purpose” than those of the other two species. Their covert feathers do show a purple sheen in the right light:

Purple Sandpipers and Dunlins are not very afraid of people on their wintering grounds; they may rest a few meters from a quiet observer. But the slightest hint of danger can trigger the whole flock to take flight in an instant—only to land nearby a moment later:

Purple Sandpipers are adapted to rocky coasts, where they feed on mussels exposed during low tides and on other invertebrates. The undersides of their feet must have a texture that allows them to walk sure‑footed on slime‑covered, slippery rocks:

 They have also evolved Silly Walks:

A distant Harbor Seal (Phoca vitulina), a frequent sight in the Inlet, always seems to look at the jetty with disappointment when it notices that this prime haul‑out spot is occupied by people:

As I was about to leave, the colors of the sunset behind a distant house caught my attention, so I took a picture, thinking little of it. Only back home—rather like the character in Antonioni’s Blowup—did I realize that the picture hides a predator the sleeping shorebirds must be on guard against. To be honest, I can’t be sure this was a flesh‑and‑blood predator and not one made of polystyrene, but the impression remains:

Readers’ wildlife photos

January 2, 2026 • 8:15 am

UC Davis Math professor (emerita) Abby Thompson sends some (mostly) intertidal photos, but from Hawaii rather than California. Abby’s captions are indented, and you can enlarge her photos by clicking on them.

We got to spend ten days before Koynezaa in Kauai, thereby missing some torrential northern California rains.    So here’s a little Hawaiian wildlife:

A not-great iphone photo:  This drama played out on our hotel walkway.  We came across a father explaining to his son that this was a momma snail taking care of her baby, a charming but inaccurate description.  In fact the “baby” is the voracious and carnivorous Rosy Wolfsnail (Euglandina rosea) which was introduced to combat the “momma” African Giant Snail (Lissachatina fulica), also an introduced species.  The result has been the extinction (by the wolfsnail) of some 8 species of endemic Hawaiian snails.  The Giant Snails (well, perhaps not this one in particular) are thriving.  The road to hell, etc.:

Cellana sandwicensis (yellow-foot ‘Ophi):

Arakawania granulata (Granulated drupe; [a gastropod]):

Actinopyga varians (Pacific white-spotted sea cucumber) Not the most attractive creature- and there are a lot of them.    They’re about 8” long and seem to just lie about.:

Colobocentrotus atratus (Shingle urchin). These very cool urchins make it look like a fleet of miniature spaceships have landed on the rocks:

Exaiptasia diaphana (pale anemone):

Gyractis sesere (colonial anemone):

Monetaria caputophidii (Hawaiin snakehead cowrie). Not sure where the snakehead part comes in:

Sunset behind the palm trees (iphone photo):

Most photos were with an Olympus TG-7, in microscope mode.

Readers’ wildlife photos

December 7, 2025 • 8:30 am

Today we have some marine mammal photos taken by Marcel van Oijen. Marcel’s captions are indented, and you can enlarge the photos by clicking on them.  Here’s a screenshot of the site, the island of Inchkeith:

Seal pup counting on the island of Inchkeith

Marcel van Oijen

The island of Inchkeith lies a few km from Scotland’s capital Edinburgh in the Firth of Forth, the sea-arm to the north. The last human to live on the island, the lighthouse-keeper, left in 1986. (The lighthouse is now controlled remotely from Edinburgh as are most lighthouses in Scotland.) Wildlife has since come back, and there is now a thriving colony of grey seals (Halichoerus grypus) producing around 900 pups each year. I took the photos below during the pup count of 29 November organised by the Forth Islands Heritage Group of volunteers.

This is near the harbour where we arrived, and we had to be careful not to get too close. Fortunately the female was busy keeping the male away from her pup. Cannibalism does happen occasionally.

Looking back to the harbour with the second group of volunteers just arriving. Note the many seals on the beach and in the water

Mating couple. The female life cycle is intense: a few weeks after giving birth and after the pup is weaned, they can be impregnated again:

This pup has moulted (i.e., lost its fluffy white baby-coat called the lanugo), so it will be three to four weeks old. At that age pups will be weaned and have to fend for themselves.

Two young pups who have just begun moulting, starting from the head:

Female seals carefully watching us:

This pup is nearly done moulting, some fluff left on top:

A moulted pup with an unusual colour, not the standard dappled grey:

Overview of ‘our’ patch of the island where we counted around 200 pups:

The most affectionate mother we saw on the island. She occasionally rolled on her back with eyes closed but always kept patting her pup with her front flipper:

Looking back to Inchkeith with fond memories!:

Readers’ wildlife photos

October 30, 2025 • 8:15 am

UC Davis math professor and Hero of Intellectual Freedom Abby Thompson sends us some intertidal photos (with one mammal). Abby’s IDs and captions are indented, and you can enlarge the photos by clicking on them.

And don’t forget to send in your photos!

A late summer entry from the tidepools, including a mystery through the microscope:

First, two handsome chitons:  these are the fellows who cling to rocks like a limpet, and, if dislodged, curl up like a pill-bug to protect their soft undersides:

(Lepidozona mertensii) Merton’s Chiton:

(Mopalia lignosa) Woody chiton:

Genus Themiste (peanut worm); the species is uncertain. The body of the worm lies below the sand.    The tentacles are very active (and very skittish), sweeping in particles towards the mouth:

I’ve posted some pictures of the deer that often come down to the beach before dawn.  The cliffs down to the beach are quite steep in places, and sadly sometimes the deer slip and fall.  This must have been a fawn (based on size).    Skip the next picture if you’re not a nature-tooth-and-claw person:

Dead deer- probably a mule deer, Odocoileus hemionus:

Diaulula odonoghuei (Northern leopard dorid):  This species is typically further north, although I’ve found it here a few times:

The next three photos are a puzzle to me, maybe some readers have a suggestion.   They’re through a microscope. I was looking at bryozoans on a piece of kelp, when I noticed some ring-like things on stems growing out of the bryozoans.    The first picture is a side view showing the stems.   In the second picture you can see the (greenish) rings forming inside one of the bryozoans- the rings seem to turn peachy as they mature.  The final picture shows the mature rings from above.   Inaturalist hasn’t come up with a suggestion so far.     From what I’ve read of marine bryozoans, I don’t think this is part of their reproductive cycle.    A tentative suggestion from the Bodega Marine Lab (thanks!!) is “stemmed diatoms”; the world is a mysterious place:

Triopha maculata– a particularly handsome nudibranch:

Readers’ wildlife photos

August 25, 2025 • 8:15 am

Today, mathematician and Hero of Intellectual Freedom, UC Davis’s Abby Thompson has more lovely intertidal pictures from California. Her captions and IDs are indented, and you can enlarge the photos by clicking on them.

The Northern California tidepools are filling with kelp, and creatures are hiding away under it.   Here are some photos while there’s still a bit of summer left.     These are from July, except for the pelicans (August 1). Thanks as usual to experts on inaturalist for some of the IDs.

Tegula funebralis (black tegula): I love these tracks on the sand at low tide; it looks as though the snails are trying to tell us something:

Closeup of the barnacle-encrusted snail from the first photo:

Hesperocyparis macrocarpa (Monterey Cypress). The trunks get stroked by many hands as people pass them on their way down to the beach:

Pelecanus occidentalis (brown pelican): There must have been a large shoal of fish near shore; the pelicans (it seemed like hundreds of them) were going nuts.    Their lethal dives, with those incredible beaks, makes their relation to dinosaurs look very convincing.  The Point Reyes peninsula is in the background:

Family Ammotheidae (Pycnogonid-sea spider): The lumpy white spots on the legs are eggs (what a place to carry them!), which I believe makes this a female.  The males carry the eggs after they are fertilized:

Tenellia lagunae (nudibranch):

The next few photos are through a microscope.  I have an ancient Leitz Wetzlar dissecting scope, with an old iphone precariously clamped over one eyepiece. There must be a better way, but I haven’t figured it out yet.

Diatoms: Genus Isthmia; Lou Jost’s beautiful post on WEIT on the Challenger Expedition and the diatoms they found  was inspiring. It’s disconcerting, as a non-biologist, to look through a microscope at a fluffy, frothy bit of seaweed (the reddish stuff) and see, scattered all through it, these incredibly regular geometric shapes:

Diatoms closeup:

Neosabellaria cementarium ((tiny) polychaete worm):

Phylum Foraminifera: This was a surprise to me, partly because I had never heard of foraminifera, but mostly because it turns out they’re single-celled organisms (like diatoms), so that’s one cell you’re seeing.   Google AI says this about the difference between diatoms and foraminifera: “Diatoms are photosynthetic algae with silica cell walls, while foraminifera are amoeboid protists with calcium carbonate or agglutinated shells.”

There are many more elaborate/complex ones than this one (there’s one that looks a lot like a loaf of challah, for example).   It’s worth googling “foraminifera” and “Ernst Haeckel” to see some amazing illustrations. The Challenger Expedition discussed by Lou Jost also collected and documented foraminifera.  According to Wikipedia, the first picture of one was by “…Robert Hooke in his 1665 book Micrographia”.  This book (available through WikiSource online) has charming sections like: “Of the Teeth of a Snail”, and “Of blue Mould, and of the first Principles of Vegetation arising from Putrefaction”.   The possible foraminifera appears as figure X in Schema 5.   He says (in Observation XI) “I view’d it every way with a better Microscope and found it on both sides, and edge-ways, to resemble the Shell of a small Water-Snail with a flat spiral Shell:” Imagine being one of the first to be able to peer into this world!

The camera for the first six pictures in an Olympus TG-7.

Readers’ wildlife photos

July 6, 2025 • 8:15 am

If all goes well, these photos from John Avise, one showing pinnipeds, will appear as his usual Sunday contribution. (I’m scheduling it in advance.) John’s captions and IDs are indented, and you can enlarge the photos by clicking on them.

Whale-watching Trips, Part 4. Pinnipeds

No, they’re not cetaceans, but seals and sea lions are other marine mammals sometimes seen on whale-watching tours out of Southern California.  This week I continue the “Whale-watching” series by showing my photos of some pinniped species that I’ve encountered on these nature excursions.

California Sea Lion (Zalophus californianus):

California Sea Lion, juvenile:

California Sea Lion, head shot:

California Sea Lion, group basking:

Harbor Seal (Phoca vitulina), swimming:

Harbor Seal, basking:

Harbor Seal, headshot:

Harbor Seal, pup nursing:

Harbor Seals, basking:

Harbor Seals, swimming and basking:

Harbor Seals, adult and pup on land: