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Friday, May 31, 2013

Trifolium wormskioldii

Close-up of Cow Clover (Trifolium wormskioldii) 


These clovers were photographed along Westshore Road between Owl Canyon and Campbell Cove on 31 May 2013 .  Here are two more views of this striking, large, native clover (sometimes called the Coast Clover or Springbank Clover).



According to Wikipedia, this species was named after a Danish botanist, Morten Wormskjold.  He participated in an 1815 Russian expedition aboard the Rurik commanded by Otto von Kotzebue.  Other famous naturalists on this expedition included Adelbert von Chamisso and Johann Friedrich von Eschscholtz.

Thursday, May 30, 2013

Lingering


I stopped by Porto Bodega after work and happened upon this male Bufflehead sitting on a rock.  It's late for Buffleheads to be in this area.  Most of them have left for more northern or inland breeding sites.  There are only about 8 records of summering Buffleheads listed in The Birds of Sonoma County (2001 and 2012).

When the Bufflehead turned slightly, the feather shafts in the left wing were quite visible.  This bird appears to be molting its wing feathers.


I know it's not officially summer yet, but it'll be interesting to see how long this Bufflehead continues to linger in Bodega Harbor.

Wednesday, May 29, 2013

Lay a purple ribbon

At the end of field work in the rocky intertidal zone on Bodega Head yesterday morning (28 May 2013), I peeked under a ledge to see this scene:


There's a lot going on the picture above, but pay particular attention to three things: 

(1) the two pale blobs these are nudibranchs (sea slugs)
(2) the O-shaped purple ring between them — this is an egg ribbon
(3) the bright pink surface in the right half of the photo — this is a sponge

Below are two close-ups of the nudibranchs.  Sorry that these aren't better photos, but you can still see that they are predominantly white with scattered yellow spots.  Interestingly, one of them has more yellow spots than the other.  This could mean that they're different species, but unfortunately I didn't have time to check more features to be certain.  They both appear to be species of Cadlina.



The next image is a close-up of the egg ribbon.  I'm wondering if one of these nudibranchs laid this egg ribbon.  I can't be sure, but it looks like it was produced recently, and there's often a "guilty-by-association" phenomenon with nudibranchs and egg masses.  I hadn't seen an egg ribbon this color before, so it seemed worth documenting.


It was interesting to see how well the egg ribbon blended in with the color of the sponge.  Nudibranchs in the genus Cadlina are known to eat sponges like this.  I don't know if the nudibranchs were feeding on the sponge, but it's a possibility.


P.S.  Click here for a better photo of Cadlina luteomarginata taken on Bodega Head last May.

Tuesday, May 28, 2013

Drifting by the dock

We've returned to California, but I can't help showing another fascinating invertebrate from San Juan Island.  And this one could be found in California, too, so it's relevant to the Bodega Head area.

One of the funnest things about the Friday Harbor Laboratories is all of the planktonic animals drifting by the dock.  It's easy to spend hours on your stomach staring at the various gelatinous creatures swimming along just below the surface, magically appearing and disappearing from view.

Eric and I brought a jar so we could gently scoop up anything interesting for photographs.  I was excited when this animal emerged from the depths.  It was ~6 cm long.


This is a colonial animal called a siphonophore.  (I've mentioned siphonophores on this blog twice before — once in January 2012 and again in April 2013.  You can check out those posts for more information about them.)  I think it's a species of Nanomia, perhaps Nanomia bijuga.  But I don't have much experience identifying siphonophores, so please correct me if you think this is something different.

This siphonophore has a gas-filled float at the top (see below for a close-up).  The float is somewhat similar to a Portuguese Man O' War float, but in this case the float is much smaller and has ruby red pigment.

In the next image you can also see the swimming bells that the siphonophore uses to propel itself.  When it contracts the bells, the siphonophore can move very quickly!


The lower portion of the siphonophore is very complex.  I don't claim to understand everything down there.  But it's made up of both reproductive and feeding structures.  In the following image, you can see some of the feeding structures.

Look for the orange coils those are called cnidobands.  And in the lower left corner, you can see a long thread-like structure trailing downward.  This might be a filament extending down from a cnidoband.  Stefan Siebert shared a neat description of these structures (and better photos) at the CreatureCast website.  (Remember that siphonophores are cnidarians so these feeding structures have stinging cells like jellyfish.)



I wish I could share more about these amazing animals, but for now it's just fun to know that they're out there.

Sunday, May 26, 2013

Multi-porpoise

After a long morning of field work yesterday, we went to look for whales near Lime Kiln Point on the west side of San Juan Island.  No Orcas for us, but nice views of several Harbor Porpoises in the slicks inside of the rips further offshore:




Saturday, May 25, 2013

Consolation prize

Well, we didn't find what we were looking for today, but near the end of our search at Eagle Cove on San Juan Island, Eric looked down into a tidepool and found this!


This is a stauromedusa.  It's about 1 cm across and attached to a piece of red algae (Mazzaella sp.).  We think it's a species of Haliclystus.

Here's a view from the side:


I don't have many resources with me, so will have to do more research on this species when I return to California.  For now here are a few more pictures of this wonderful animal.



The next image shows the stauromedusa holding a crab zoea (larva) that it had just captured.  You can see the crab zoea's eyes and its spine pointing backwards.  I don't know how often stauromedusae eat crab zoeae, but this one caught at least three while we were watching it today.


I first wrote about stauromedusae in November, so click here to review their anatomy and a little bit about their biology and read more about a different species that we found on Bodega Head last fall.

Friday, May 24, 2013

Images of the day

A few images from the day traveling to San Juan Island and a short walk on the island:

 
Purple Martin near the ferry dock.


The skies cleared just in time to see the Olympics from the ferry. 


Shoreline near Friday Harbor.


Close-up of a still-to-be-identified darner.


Full moon rising at the end of a beautiful day.

Thursday, May 23, 2013

The kernel crusher

It figures that the day after I leave California, two birds show up in Bodega Harbor that I haven't seen locally yet — a Brown Booby and a Franklin's Gull.  (Perhaps someone can ask them to hang around for a few more days until I return?)

But I was pleased to see the species below along the Oregon coast.  Although I wish I had better photos, the conditions were pretty stormy (you can tell that the birds were wet).  I hadn't encountered this species since leaving New England.  I tried to find them in Point Reyes Station this winter, but wasn't able to locate them.  They're considered accidental on Bodega Head, so there must be at least one record, but I don't have The Birds of Sonoma County with me right now, so can't look that up at the moment.

We were doing a little indoor work and heard some loud calls outside.  I looked up into the trees to see these birds:


This is a pair of Evening Grosbeaks (Coccothraustes vespertinus).  The female is on the right, and the male is a little hidden behind the branch to the left.

Eventually the male came out into the open for a few seconds. 


Later he moved to a position where you could see the the very large, greenish conical bill and the earthy brown and orange feathers.  Also note the bright yellow forehead and white wing patch.


At one point there were also Red Crossbills in the same tree.  Here's a view showing the female Evening Grosbeak with a female Red Crossbill.


And another with a pair of Evening Grosbeaks and a pair of Red Crossbills.  Can you find all four birds?


The female Evening Grosbeak is in the upper left corner.  The male Evening Grosbeak is in the center at the lower edge of the photo.  The pair of Red Crossbills is at the upper right corner (the yellow female is just below and to the left of the red male.)

I was intrigued to learn that geographically distinct call types have been described for Evening Grosbeaks, just as they have for Red Crossbills.  I now wish I had been able to record these grosbeaks.  Next time!

P.S.  The genus, Coccothraustes, apparently means "kernel crusher," in reference to the massive bill and its function in shattering seeds.

Wednesday, May 22, 2013

Like water off a...

...tattler's back?

This Wandering Tattler was perched along the rocky shore near Yachats, Oregon on 22 May 2013.


Although intermittent, the rain was coming down pretty hard at times.  In the next image, you can see raindrops falling diagonally across the picture and water droplets beaded up on the tattler's back.
 


Tuesday, May 21, 2013

Violet-green

Traveled to the central Oregon coast today and didn't arrive until early evening.  There was a nice flock of swallows (at least three species) feeding over a nearby river mouth.  


There were scattered rain showers and the light was very dim, so this isn't a great shot — nevermind the challenge of photographing swallows in flight! — but it still provides a glimpse of a Violet-green Swallow (Tachycineta thalassina).

Monday, May 20, 2013

Morning glory


Coastal Bluff Morning-Glory (Calystegia purpurata subsp. saxicola) 


This photograph is from 14 May 2011, but 2013 also seems to be a very good year for this native perennial on Bodega Head.

P.S.  The subspecies name "saxicola" means "rock-dwelling."

P.P.S.  Calflora calls this species the Bodega Morning-Glory!

Sunday, May 19, 2013

Revealing

American White Pelicans foraging in Bodega Harbor, 19 May 2013


I like this picture because it reveals quite a bit about white pelicans.

About foraging — White pelicans often forage in groups.  They feed by dipping their bills into shallow water, and often do so synchronously.  Note the raised wing posture, which I'm guessing is for balance while reaching below the surface.

About habitat use — You can see that these pelicans are in a relatively sheltered location with mudflats in the background.  Scanning carefully, you will also find strands of eelgrass draped around some of the birds (especially the second bird from the left), indicating use of seagrass beds.

About reproduction — Look closely for birds with gray feathers on their crowns.  This coloration is found in chick-feeding adults.  (White pelicans don't breed on the coast, but they've arrived here after nesting at inland lakes.)  And the large rounded "horn" on the bill of some individuals is also only present during the breeding season (it's usually shed after eggs are laid).

About species interactions — Note the Great Egret in the background.  The egret appeared to be "attending" this flock of pelicans, waiting for fish that the pelicans flushed or missed. 


Saturday, May 18, 2013

California ovipositing

It was pretty breezy this afternoon, so I checked out one of the more sheltered dune ponds and noticed this dragonfly at the surface of the water.


This female California Darner (Rhionaeschna californica) was ovipositing (laying eggs) in the leaves of the submerged vegetation.  At this stage, she has already mated with a male, so the eggs are fertilized.


A male California Darner was hovering nearby.  It's likely he was the last male to mate with this female.  The male was actively guarding the female, defending her against visits by other males.  (There's a good reason for doing so, as it's thought that dragonflies can remove the sperm from previous matings.  By chasing away other males, he protects his investment.)


Here's a close-up of the male in flight:


The eggs that the female deposited will eventually hatch into larvae (dragonfly nymphs).  In large species such as this, the larval stage will often last for at least a year or more.  Then the nymph will undergo metamorphosis, crawl up a plant stem into the air, and break out of its nymphal skin to emerge as a flying dragonfly.  The adult dragonfly may live for a month or two.

Friday, May 17, 2013

To boldly go

 
Loki's Chiton (Tonicella lokii), photographed on Bodega Head, 4 July 2011

Thursday, May 16, 2013

The little explorer

I looked down among some grasses and sedges near Campbell Cove today to see a small jumping spider with a highly patterned abdomen:


It was doing a lot of exploring...



...and looking around.


I'm wondering if this might be a species of Phidippus, but I'm not sure yet.  I'll have to ask for some help and will report back if anyone has feedback about an identification.


Wednesday, May 15, 2013

Along came a sea spider

In late April, I was looking through a microscope trying to photograph a local hydroid when I was distracted by something orange with long legs:


I zoomed in for a closer look:


This is a pycnogonid, or sea spider.  It's a little hard to make everything out at first, but I just had to post these pictures because this animal is so unusual.  

This sea spider is mostly transparent.  The orange lines are branches of the gut that extend throughout the body and into each leg.  (Somehow this patterning made the sea spider look like some sort of Halloween skeleton to me!)

The head is on the left side and if you look carefully you can see small silvery spots that are the eyes. [There are four eyes, but all four are not always visible.]  The two arching appendages on either side of the eyes are chelicerae — the presence of chelicerae tells you that sea spiders are related to horseshoe crabs, spiders, and scorpions.

After that, the body (or trunk) is narrow, but there are very long legs extending out to either side.  In the next photo, the sea spider has turned to face away from the camera and is now crawling along a branch of the hydroid.  Note the sharp curved claws at the tips of its legs for holding on (reminiscent of a sloth).


Close-up of leg and claw wrapped around hydroid branch:



I believe this sea spider had just eaten one of the hydroid polyps see the pink mass next to the sea spider in the following image.  The sea spider has a long proboscis that it uses to suck fluids out of its prey.


There are many other interesting facts to share about sea spiders, but I'll save those for another night. 

For now, since you've become familiar with what this sea spider looks like, can you find it in the photo below?  The transparent-and-orange coloration is effective camouflage against the backdrop of the hydroid, but I think you'll be able to find it if you search carefully.


The sea spider is in the lower right corner, at the lower end of the rightmost brown hydroid branch.