Saturday, December 26, 2015

Near Chatham Light


I wasn't sure how today was going to go, but it ended up that I had a few free hours in the afternoon, so I made a dash out to the Cape.  I stopped at Chatham Light first, and noticed quite a few gulls feeding just inside the break. 

The quick wing beat of some smaller gulls caught my eye:


They were Black-legged Kittiwakes (Rissa tridactyla)!  I still haven't caught up with Black-legged Kittiwakes in California yet, so it was nice to spend some time with them in Massachusetts today.

Most of the kittiwakes were immature, with broad black stripes across their wings and dark outer primaries:


If you haven't seen kittiwakes before, note also the dark bill, dark spot (or smudge) behind the eye, and the dark collar across the hindneck. 

I was curious about what the kittiwakes were feeding on.  I saw two birds catch fish by surface-plunging:


I realized I didn't know very much about kittiwake prey.  In Alaska, three species of fish make up the majority of their prey: Pacific Sand Lance, Capelin, and Pacific Herring.  Also important are fish in the gadid (cod) family as well as lanternfishes.  It turns out that much less is known about the prey of kittiwakes wintering in the western Atlantic.  In fact, here's a quote from the Birds of North America Online (Hatch et al. 2009): "No information on food of wintering kittiwakes on east coast." 

I'm not a fish expert, but I'm wondering if the prey in the picture above is an American Sand Lance (Ammodytes americana).  It's very long and slender, and appeared to have a greenish back.  If you have any thoughts about the identity of the fish, let me know!

Here's one more picture more of seascape shot.  It's hard for me to believe that it's warmer in Massachusetts than it is in Bodega Bay right now, but it sure was nice to spend a beautiful December afternoon with kittiwakes!


Friday, December 25, 2015

Opalescent


Opalescent Nudibranch (Hermissenda crassicornis
Photographed on Bodega Head in May 2013.

Tuesday, December 22, 2015

"The hardest thing of all to see..."


Ruby-crowned Kinglet (Regulus calendula), Santa Rosa, 21 November 2015

A picture from last month, but one I really like, and was reminded of recently when I read this quote:

"The hardest thing of all to see is what is really there." (J.A. Baker, The Peregrine, 1967).

Many of us have observed Ruby-crowned Kinglets, but have you seen those beautiful yellow edges to the wing and tail feathers?  And have you wondered why they're there?

And have you noticed the wonderful lichens where the kinglets search for food?

It is hard, but I'm glad there's so much more to see.

Monday, December 21, 2015

View from above


The view from ~37,000 feet (above the Great Lakes).


Happy Solstice!
 

Sunday, December 20, 2015

Calcareous


A pheasant snail (Eulithidium pulloides), grazing along a blade of surfgrass (Phyllospadix sp.).  I first showed pictures of the shells of these snails in April 2014, but I haven't shown the entire animal yet.  (They're hard to find because they're quite small only a few millimeters long.)

One of the interesting characteristics of this species is its operculum (or "trapdoor").  In most marine snails, the operculum is made of a protein material (think about a moon snail operculum).  But in some species, including these pheasant snails, the operculum is harder and made of calcium carbonate.  

See below for a close-up of the white, calcareous operculum:


Can you think of reasons why it might be helpful for a snail to have a calcareous operculum?  (One possibility is mentioned at the bottom of this post.)

If you're interested in finding a pheasant snail, try searching the bases of surfgrass clumps during a good low tide.  


P.S. Calcified opercula are thought to be a defense against predators.

Saturday, December 19, 2015

Surf and a sailor


Looking north from Salmon Creek Beach, 19 December 2015



We noticed one small By-the-wind Sailor (Velella velella) washed ashore today.  This individual was ~2 cm long.

Wednesday, December 16, 2015

Breakfast in the sweetgum

The birds returned for "breakfast" in the sweetgum this morning.  

When I lived in Massachusetts, I didn't see Pine Siskins that often, so it's been fun getting to know them better in California.

Here's a classic pose, hanging onto a sweetgum seed pod:



The siskins frequently feed upside down, and often in close proximity to each other:



After feeding, they will sometimes sit quietly in the sun with their eyes closed: 



The activity of the siskins attracted other birds.  While the siskins would roll the seeds around in their bills, the Chestnut-backed Chickadees had a slightly different feeding strategy.  They would extract a seed, then take it to a perch and hammer on the seed to separate it from its winged covering.



The Lesser Goldfinches also hung from the pods, and fed in a similar way to the siskins, maneuvering the seeds in their bills.  How many goldfinches can you find in the photo below?


[There are four goldfinches in the photo above — three near the center (top, middle, bottom), and one in the upper right corner.]

Tuesday, December 15, 2015

Fluffed up


Pine Siskin (Spinus pinus) fluffed up against the cold (~35°F) early this morning.

A large flock of siskins was feeding in a sweetgum tree in our yard.  Their activity level seemed to attract other birds.  The siskins were joined by Lesser Goldfinches, Cedar Waxwings, a Red-breasted Nuthatch (see below), and Chestnut-backed Chickadees.



It's already 36°F here tonight (at ~10 p.m. in Cotati), and it's predicted to reach 30°F by morning.  Brrrr!

Monday, December 14, 2015

Winter's coming


I didn't get a chance to post this wintery scene.  What do you see in the frost patterns above?  

My first thought was that it looked like a winter landscape with a tree and shrubs, and stars, and birds.

This picture was taken of our windshield in Cotati on 29 November 2015.

Sunday, December 13, 2015

Soaking wet


Western Scrub-Jay, 12 December 2015. 

(The water droplets are a result of vigorous bathing by the jay!)

Saturday, December 12, 2015

They're back


Last spring, a large flock of Cedar Waxwings visited the berries in our yard.  

They've returned during the last few days.



Cedar Waxwings have a very distinctive silhouette:
 



P.S.  It's been many years since I've seen a Bohemian Waxwing.  Although generally found in more northern areas, they can occur in California.  I'd love to see one here!
 

Friday, December 11, 2015

West swell

Waves reached heights of ~18-20 feet this morning.

I took a few pictures for documentation.  I had a hard time picking one picture, so you get to choose your favorite among three examples.  [Click on each one for slightly larger versions.]
 




(Note the gull in the upper right corner for scale.)



 

Thursday, December 10, 2015

Swirls and splash

It was a +6.2' tide this morning.  (That's relatively high for Bodega Bay.)  On my way to the Bodega Bay Post Office, movement caught my eye.  Large flocks of shorebirds were swirling over the harbor.  

The nearby salt marsh was almost entirely flooded.  Hundreds of shorebirds were trying to fit on the few small islands of grass remaining above water:



On the outer coast, the swell was impressive, crashing against the rocks.  I think the waves were ~12 feet at this time:


Right now (at ~9 p.m.) wave heights at the Bodega Bay buoy are reading 24 feet! 

P.S.  For the record, there was a significant southward movement of loons this morning.
 

Wednesday, December 9, 2015

Striped barrels

Back on 12 November 2014, I showed an egg mass from a local snail that lives on the tidal flats in Bodega Harbor a Striped Barrel Snail (Rictaxis punctocaelatus).  

In that post, I mentioned that I had found the egg masses, but I hadn't found an adult snail yet.  That was true until December 4.  Once I learned how to see the adult snails, I realized that they're common to abundant in Bodega Harbor this year. 

Although most of the snails were buried just below the surface of the sand, here's an example of one that was crawling on the surface:


I've been doing shorebird surveys in Bodega Harbor for over 10 years now.  I hadn't encountered these snails until this year, so I'm wondering if there's something unusual about the conditions this year (or whether I just missed them if they weren't as common and I didn't know how to look for them).

But if you'd like to see some of these intriguing snails, this would be a good year to look for them in Bodega Harbor!

Sunday, December 6, 2015

"Shield up"

I think it was about 8 years ago when I first saw a Pear Marginella (Granulina margaritula).


This is a very small snail.  Pear Marginellas reach a maximum length of ~2-3 mm.  Here's a photo of the same snail, with more of the rock surface (and associated organisms) for scale:


I thought it would be fun to introduce you to this snail because it has "a trick up its sleeve."

Below is a close-up, showing the pale shell, the long foot (trailing behind the shell), and the anterior end with two tentacles, two dark eyes, and a gold-flecked siphon between the eyes.

Note also the edge of the mantle the darker band (brown and gold) along the margin of the shell.


When a Pear Marginella senses a predator, it extends its mantle to cover its shell.  The mantle offers protection — e.g., a slippery surface and release of toxic chemicals.

Below is a short video clip of a Pear Marginella encountering a predatory sea star.  First you will see the snail exploring on its own.  Then you'll notice a portion of a sea star arm (with tubefeet) in the left corner.  Watch the snail raise its mantle up over its shell.  The slippery surface acts as a shield, likely making it difficult for the sea star's tubefeet to hold onto the snail's shell.  (Later, the snail also starts "running away" from the sea star very quickly!)

There's a bonus: The mantle is beautiful!  Brown, with orange, gold, and blue flecks. 
 



Pear Marginellas aren't the only snails that cover their shells with their mantles for defense, but they're certainly one of the prettiest!

P.S.  The "Pear" in the common name comes from the shape of the shell.  But I also love the translation of its scientific name "Granulina" means "little pearl." 

Saturday, December 5, 2015

Gray and white


Snowy Plover, Dillon Beach, 5 December 2015

Friday, December 4, 2015

White peaks


12-foot northwest swell, with east winds at about 5-10 knots 



Photographed from Bodega Head on 4 December 2015

Wednesday, December 2, 2015

Olive's in Sonoma County


Tonight I'm very excited to share such a beautiful nudibranch with all of you. 

While conducting surveys on 25 November 2015, Eric spotted two of these Olive's Aeolids (Anteaeolidiella oliviae) in the low intertidal zone at Pinnacle Gulch.

Olive's Aeolid is generally a southern species.  In fact, it appears that it reaches its northern limit in Mendocino County.  Although there were at least two observations of this species in Sonoma County (Coleman Beach and Shell Beach) and one observation in Mendocino County (Fort Bragg) earlier in the year, I haven't been able to find any records further north.  As with Hilton's Aeolid, the presence of Olive's Aeolid in Sonoma County this year may be associated with recent warm water conditions along our coast.

Some of this nudibranch's features are easy to see the orange cerata (projections on its back) and the darker rhinophores (sensory organs).  Here's a close-up of the cerata (below).  Note that they have pale tips.



This next photo also shows the white speckles on the body, and two small black eyes behind the rhinophores.  (And note that the rhinophores, like the cerata, also have white tips.)



Eric was also able to shoot a short video of this nudibranch.  This individual was ~2 cm long.  Because they're rare this far north, we felt lucky to encounter Olive's Aeolid.  We hope you enjoy learning about it as much as we did!

anteaeolidiella oliviae sanford from Jackie Sones on Vimeo


P.S.  CORRIGENDUM (3 December 2015): I updated the distribution description above to reflect a record from Mendocino County.

Tuesday, December 1, 2015

Do you like my spots?


A mystery close-up for you.  Above is a highly magnified view.  The next two images show the upper portions of the branched tentacles:




The following three images provide views of the body.
 

The anterior (front) end, with tentacles retracted:



The mid-section: 



The posterior (back) end:



These pictures serve as an introduction to a wonderful sea cucumber, Pentamera pediparva!

This is a northern species with a reported geographic range of British Columbia to northern California.  We are trying to learn more about this species, but this could be the first record south of Eureka, CA.

Do you remember that sea cucumbers have small, calcified plates called ossicles embedded in their skin?  They're the shiny pieces visible in the first photograph of this post.  The ossicles have very distinctive shapes and are important for species-level identification.

Here's a look at some isolated ossicles from this sea cucumber.  The top photos (blue background) are from the tubefeet, while the bottom photos (gray background) are from the skin.  We were uncertain about the identity of this cucumber until we saw these ossicles and matched them with a diagram:



Below is an illustration of Pentamera pediparva ossicles.  Compare their shapes with the photos above:

 Modified from Sea Cucumbers of British Columbia, Southeast Alaska and Puget Sound (Lambert 1997). 


We're very excited about the possibility of documenting a new site for this little-known sea cucumber.  Eric discovered it on a low intertidal boulder along the Bodega Bay shoreline on 11 November 2015.


P.S.  Hello to Casey and other sea cucumber enthusiasts! 

Monday, November 30, 2015

Suckers for the low zone

This might be tough, but do you want to guess what type of animal this is?  This is a close-up view of one end of the animal:


If you think that looks like a sucker, you're right!  It's a magnified view of a caudal sucker (the tail end).

Here's a look at the other end:


If you think that looks like a sucker, you're right again!  ;)  It's a magnified view of an oral sucker (the mouth end). 

I'll also tell you that this is a marine invertebrate.  So you need to visualize an animal with suckers at both ends...

Are you ready for the answer?

The next photo will reveal the entire animal after Eric discovered it attached to a rock in the low intertidal zone:


If you think that looks like a leech, you're right!  This is Trachelobdella oregonensis.   It was ~30 mm long when outstretched.

The diagram below highlights some of the main features of this species.  Look for (1) overall dark coloration; (2) the pale caudal sucker; (3) the small oral sucker with lighter patterning; and (4) 10 pairs of "pulsatile vesicles" = the bumps along the sides.

Modified from The Light and Smith Manual (edited by James Carlton) 


And here's a view of the leech while it was attached to the side of a bowl by its caudal sucker.


Although this individual was not attached to a fish, Trachelobdella oregonensis is known to be a parasite on a specific fish host — Cabezon (Scorpanichthys marmoratus).

The Light and Smith Manual states that this species has only been found from the central Oregon coast.  However, I searched the Smithsonian's invertebrate collection, and two California locations are represented: Crescent City and Pacific Grove.  So this record from 26 November 2015 could be a first for the Bodega Bay area.  [Yes, we found this leech on Thanksgiving (after our holiday meal) — there are so many interesting things to discover in the low intertidal zone that we couldn't resist a short field trip during one of the better low tides of the year!]

One more quick fact: Of ~700 species of leeches worldwide, only ~100 of those are marine.