Saturday, July 30, 2022

The hydroids are lovely

  

Three-lined Nudibranch (Coryphella trilineata) strolling among a forest of Orange Hydroid (Garveia annulata) polyps.  Photographed in the low intertidal zone on 14 July 2022. 

P.S.  I couldn't help hearing the Robert Frost poem when I looked at this photo, but instead of "The woods are lovely, dark and deep..." I heard hydroids instead of woods!

Wednesday, July 27, 2022

Spouts and flukes

  

A Gray Whale (Eschrichtius robustus) has been observed fairly close to shore off Bodega Head during the past few days.  (And a few days ago I could also see quite a few Humpback Whales farther out towards the horizon.)

Here's another view of the Gray Whale heading away:

 

Tuesday, July 26, 2022

Sharing a shelf

 
Pigeon Guillemots (Cepphus columba), photographed 25 June 2022
 

Monday, July 25, 2022

Auklet -- Part 2

 

Last night I mentioned that I had seen a couple of Rhinoceros Auklets close to shore.  Those were adults, but today I noticed a different individual that appears to be a juvenile.

Although there have been observations in previous years hinting that Rhinoceros Auklets might have nested on Bodega Head, I don't think there are any definitive records.  

Seeing a juvenile close to shore in July hints at the possibility of nesting locally, although the alternative is that this juvenile originated from a nesting site elsewhere (e.g., the Farallon Islands or a site farther north) and then dispersed to our area.

 
I had a large lens today and this bird was quite close to shore, so here's a zoomed in view of the bill with a tiny "horn" (in this case, a bump) just starting to appear at the base of the upper mandible:
 
 
P.S.  I came across a fun audio recording of Rhinoceros Auklets adults and a begging juvenile.  If you want to hear what they sound like, here's the link to the recording.
 

Sunday, July 24, 2022

Flybys

  

Not a great photo, but a fun story.  I've been having some trouble with my camera/lens.  Today I noticed some guillemots close to shore, so I started testing my lens by practicing focusing on guillemots flying by.  I would see a bird approaching from a distance, raise my lens, and try to focus.  

I had done this several times when I looked through and noticed not guillemots, but auklets!  I don't see Rhinoceros Auklets (Cerorhinca monocerata) from shore that often, especially during the summer, so it was a nice surprise.  Not sure if they'll stay around, but if you're interested in seeing auklets, it might be worth scanning nearshore areas off Bodega Head.

Saturday, July 23, 2022

Blocks of color

 
A fun isopod (Synidotea sp.) photographed in the low intertidal zone on 15 July 2022.  (There are two individuals in this image; the larger male is holding a smaller female underneath him.)
 
I was struck by the interesting blocks of colors.  And even more so a little while later when I was trying to photograph a cluster of sea spiders (pycnogonids).  
 
I didn't noticed it at first, but a smaller isopod with similar coloration was hidden among the hydroids and sea spiders.  Can you find the isopod in the image below?
 
 
The isopod is very close to the center of the image.  
 
I've circled it in the photo below.  (Its head is down and to the left side of the circle.)
 
You can see how well the various colors of the isopod blend in with the sand grains, hydroid stalks (red/brown), and scattered shell fragments.

 

Wednesday, July 20, 2022

Neighborhood watch

  

I was doing some yard work after dinner tonight (20 July 2022) and kept hearing a young Cooper's Hawk (Accipiter cooperii) calling -- a high-pitched, descending wheeeer.  When I took a break, I looked around a spotted the hawk perched in a fir tree, probably a few blocks away.  The sound really carries!   

The hawk didn't come much closer, but here are a few more quick images.  I'm guessing this bird fledged from a nest somewhere nearby, but I'm not sure where.

 



 
P.S.  I didn't record the calls of this bird tonight, but if you want to hear an example of a Cooper's Hawk juvenile calling, check out this species account on Cornell's All About Birds page.

Tuesday, July 19, 2022

Roses and diamonds

  

A little surprising, but Abby observed this Hopkins' Rose nudibranch (Okenia rosacea) near Dillon Beach on 16 July 2022.  The last time this species appeared in this area was during the marine heatwaves of 2014-2016.  With seawater temperatures so cold this year, I wouldn't have had this nudibranch on my radar, but so it goes!  If you come across this species this year, I'd love to hear about any additional sightings.

And here's another nice nudibranch sighting: Eric spotted this gorgeous Diamondback Tritonia (Tritonia festiva) this past weekend:

 
 With many thanks to Abby and Eric for sharing their great photos!

Monday, July 18, 2022

In the greenery

  

Recently we were noticing some beautiful green sculpins hanging out near some green algae in a high intertidal zone pool.  

After looking around a bit, I think we found three different ages.  Below are two more individuals that I think are likely the same species, an older and younger individual:

 

 
Once again, I'm not sure which species of sculpin this is, but some day I'll figure it out.  (I'm not totally sure of the total number, but there could be something like 16 species of intertidal sculpins in this area!)
 

Sunday, July 17, 2022

Colors like stones

  

 
Whew, we had a long week of field work during the good low tides this past week.  On the side, Eric managed to photograph this beautiful sculpin.  It looked just like the surrounding stones!
 
Here's a close-up of its wonderful marbled patterning:
 
 
Many thanks to Eric for sharing these images.  If anyone has thoughts about which species of sculpin this, we'd love to learn more.
 

Friday, July 15, 2022

Upward projection

  


A close-up mystery photo!  

Can you guess what it might be?

[You can click on the image for a larger view.]

Those clusters of pink, finger-like projections are called papulae.  They extend above this animal's skin and are sites for respiration (gas exchange).

And the answer is...


 
The first photo was an extreme close-up of the upper surface of a Leather Star (Dermasterias imbricata).  Photographed 15 July 2022.

Thursday, July 14, 2022

Curled up

  

Quick shot of a snailfish (Liparis sp.) photographed in the rocky intertidal zone on 14 July 2022

Tuesday, July 12, 2022

Hiding among the mussels

  

Quick shot of a Flat Porcelain Crab (Petrolisthes cinctipes) in a mussel bed, 12 July 2022.

Sunday, July 10, 2022

Like granite

  

Fingered Limpets (Lottia digitalis), Eroded Periwinkles (Littorina keenae), and a few acorn barnacles (Chthamalus dalli) on Bodega Head granite, photographed 9 July 2022.

Saturday, July 9, 2022

Nibbling

  

I was helping Emma and Fern scout some potential research sites this afternoon (9 July 2022) and we started to notice some Western Tussock Moth caterpillars (Orgyia vetusta) in the high intertidal zone.  Eventually we discovered that the caterpillars were coming from the top of the bluff where they had been feeding on lupines.  At one point Fern looked down to see the scene shown above a Lined Shore Crab (Pachygrapsus crassipes) feeding on one of the caterpillars!  I haven't seen this before, so it seemed worth documenting.

Earlier in the day I had noticed a few of these caterpillars, but in this case what caught my eye is that the caterpillars were eating seaweed!  Here's a Western Tussock Moth caterpillar nibbling on Ulva intestinalis:

 
P.S.  With thanks to Fern and Emma for sharing their observations today!

Wednesday, July 6, 2022

An iridescent neighbor

  

This snail can be quite common in the rocky intertidal zone, but it's small enough (only ~4 mm long) that you might not notice it.  Meet Lirularia succincta!  Photographed 4 July 2022.

Tuesday, July 5, 2022

Update about NHBH e-mail service

  

This is a quick note to let everyone know that I'm transitioning to a different e-mail service for the Natural History of Bodega Head blog post e-mail messages.  

If you subscribed to the e-mail service before last summer, you have been receiving messages from Google (Feedburner).  However, that service has been discontinued (although I know some of you have still been receiving occasional messages). Soon you will no longer receive messages from Google.  

The new e-mail service is called follow.it.  If you have signed up to receive blog posts in the past, then you might see a banner at the top of the new e-mail messages explaining that I have transferred subscribers to the new follow.it service.  This is a legitimate message.  You can click on a link to confirm you'd still like to receive e-mails from the Natural History of Bodega Head.  Or you can also decline if you no longer want to receive these e-mails.

Also, if you know anyone who tried to subscribe during the past year and wasn't successful, the good news is that you can direct them to the bottom of the main NHBH web page where the subscription form is now functional.

I apologize for the issues with the e-mail service during the past year.  I'm hopeful that this will be a workable solution.  Thanks again for your interest in the Natural History of Bodega Head!

P.S.  The photo shows an Elegant Tern...because I'm turning the page to a new service!  :)

Monday, July 4, 2022

The Dove Snail Attacks!

I had a bit of an eyebrow-raising experience today.  I was trying to photograph a common snail, the Carinate Dove Snail (Alia carinata).  This marine snail can be found in a variety of habitats, e.g., rocky shores in tidepools and among surfgrass and seaweeds and in harbors among eelgrass.  It's fairly small (most individuals are probably ~10 mm long), elongate, and usually brownish/black in color.  Here's an example:

 
This species is common enough that you can overlook it.  But I needed a photograph, so I was looking at several of them under a microscope today when I came across one in a puzzling position.  I wasn't sure what was going on at first:
 
 
So that's the snail, with its siphon extended up and to the right and its foot flat against the surfgrass blade (in this photo the foot has blue highlights).  You can see the snail's short tentacles, and you can also see a small dark eye on the right hand tentacle.  But what's below the tentacles?  Here's a side view:
 
 
Ahhh!  The snail had extended its proboscis (a tubular feeding structure) into an egg capsule filled with developing larvae.  It was vacuuming up the veliger larvae!  I hadn't seen this behavior before, so I wasn't sure I was interpreting it correctly at first, but there was no doubt.  The snail reached around inside the egg capsule and cleaned out almost every developing larva.  (The egg capsule/larvae belong to a different snail species, Lacuna marmorata.)
 
Even better, Eric wasn't far away and he came over just in time to capture a video of this fascinating feeding behavior (see below).  
 
I loved learning something new and unusual about a common local snail.  In some ways the name "dove snail" suggests a rather sedate snail, but I'll never look at Alia the same way again!
 
And here's the best part the video!  Watch for the snail approaching the egg capsule, inserting its proboscis inside, then using suction and its tongue-like radula to ingest the tiny larval snails.  You'll see the radula flicking in/out at the tip of the proboscis.  (At this stage, the larval snails have shiny little shells.)
 

 
 
Many thanks to Eric for a memorable video!
 

Sunday, July 3, 2022

Stars and stripes

 
Northern Opalescent Nudibranch (Hermissenda crassicornis), photographed 1 July 2022
 
Happy Fourth of July!
 

Saturday, July 2, 2022

Olive's at the coast

  

Eric's class was conducting a nudibranch survey recently, and thanks to Zoe's sharp eyes we were introduced to an interesting sea slug meet Olive's Sapsucker (Hermaea oliviae)!  This is the first time we've encountered this species.

It's easy to understand why this sea slug isn't seen that often.  They're tiny this one was only ~5 mm long.  And they look a lot like the algae they eat in this case, Polysiphonia (perhaps Polysiphonia hendryi).

Sacoglossan slugs look similar to nudibranchs, but note the rolled (rather than rounded) rhinophores (the sensory structures that look like tentacles in front of the eyes).

Here's the entire animal (below).  It was fun to see them cruising around!

 
P.S.  With many thanks to Zoe for spotting such a cool little slug! 
 
P.P.S.  Thanks to Jeff for assistance with this identification.
 
P.P.P.S.  For an example of a different species of sap-sucking sea slug, see the post called "One cell at a time" on 23 September 2017.

Friday, July 1, 2022

Early summer

  

Early summer view with the yellow-flowering shrub called Lizard Tail or Seaside Woolly Sunflower (Eriophyllum staechadifolium), 30 June 2022