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Tuesday, April 30, 2013

Seablush


Shortspur Seablush or Rosy Plectritis (Plectritis congesta) 

This native annual wildflower is encountered occasionally on grassy hillsides on Bodega Head.  Most of the small, pinkish flowers are found in dense clusters at the tip of the angular stem.  The leaves are fairly broad, often oblong or elliptic in shape, and may clasp the stem. 

The photograph above is from 24 April 2013, but the one below is from 10 May 2006.


P.S.  Happy May Day!

Monday, April 29, 2013

Resting among the kelp

Late Sunday afternoon I encountered a few shorebirds roosting among the dried Bull Kelp on Salmon Creek Beach.  The brown coloration of the Whimbrel was an especially good match, making them hard to see at first.  How many can you spot in the picture below?  (If you're not familiar with Whimbrel, they're the large brown shorebirds with the decurved bills.)


There are eight Whimbrel in the image above.  Four spread out along the back edge of the kelp, one on the far left, one near the center, and two on the right.  There's another cluster of four in the middle of the kelp, just right of center.  Below I've zoomed in on this group of four so you can see them better.


If you scan the photo above closely, you might be able to find two other shorebirds!  There's a smaller sandpiper and a plover.  Can you find them?


I've cropped the picture a little more to help:


In the upper right corner there's a Dunlin (with red back and black belly) and a Semipalmated Plover (with black forehead and black neck ring).

The kelp and driftwood on the beach provide important resting sites for these shorebirds as they migrate northward along the coast.
 

Sunday, April 28, 2013

A long way to go

A few days ago Chris wrote to report extremely large numbers of crab larvae swimming in Tomales Bay.  Several weeks ago we heard that researchers were catching record high numbers of crab larvae in Bodega Harbor.  Today I saw drift lines of crab larvae molts on Salmon Creek Beach.  So, here we go.  

If you've eaten Dungeness Crab (Cancer magister), or have encountered adult crabs, but haven't yet seen one in the larval stage before, this is what a Dungeness Crab looks like when it's swimming around in the ocean before it undergoes metamorphosis and becomes a juvenile crab that lives on the bottom:


This is a Dungeness Crab megalopa.  It's quite large for a larval crab.  In the photo above, the length from the eyes to the base of the prominent rear spine is about 8-10 mm.  At this stage it still has a long, narrow abdomen.  In the photo above, the abdomen is tucked up underneath the body.  But when the crab is swimming, it's extended out behind the crab (see below).


And here's a nice close-up:


The megalopa is the final larval stage.  When the megalopa molts, it goes through an amazing transformation (like emerging from a magician's hat!) and becomes a juvenile crab:


The carapace (back) of this juvenile was only ~1 cm across.  It has a long way to go before becoming legal size.  In this area, a legal size Dungeness Crab is 5.75 inches (14.6 cm) carapace width.  It will take a crab approximately 3.5-4 years to reach that size.

The basic reproductive cycle for Dungeness Crabs looks something like this:

- adults mate during April-September
- females with eggs from November-February
- eggs start hatching in December, peak in March
- larvae spend 3-5 months in the plankton passing through several stages (1 protozoea, 5 zoeal, 1 megalopa)
- metamorphosis to juvenile benthic crabs during April-June
- approximately 1.5 years (11 molts) to sexual maturity (carapace width 10 cm or 4 inches)


Saturday, April 27, 2013

Rings and a fighter

We saw quite a few species of nudibranchs (sea slugs) at Pacific Grove on 26 April 2013, but unfortunately I only had time to photograph a couple.

Here are two examples: one species that also occurs on Bodega Head, and another species that doesn't but should be watched for as its current northern limit is Duxbury Reef in Bolinas.


This is a Ring-spotted Dorid (Diaulula sandiegensis).  The dark, ring-shaped spots on the pale background are distinctive.  The number of spots varies, with northern individuals tending to have more spots.  (Some of the individuals I've encountered on Bodega Head have a yellowish hue.)  Ring-spotted Dorids eat sponges.  Here's one more view in a slightly different position:


The next species is one that hasn't been observed on Bodega Head yet.


This is a Fighting Phidiana (Phidiana hiltoni, formerly Phidiana pugnax).  Note the very broad oral tentacles with the narrow orange stripe, the rhinophores with orange at the base, and the dense and colorful cerata along the back (black with orange, pink, and white markings).  Fighting Phidianas eat hydroids, but they also attack and consume other nudibranchs, hence their name.  Here's a close-up:


Any sightings of Phidiana hiltoni north of Bolinas would represent a range extension and would be of great interest, so if you see this species, take pictures and let us know!

Friday, April 26, 2013

Short spines and blue rings

We spent this morning tidepooling in Pacific Grove, so I'll probably feature some observations from that outing during the next few days.  The low tide was very early, so this post will be simple.

Here are two extreme close-ups to start with:



Do you have any guesses about what type of animal this is?  
The answer is in the image below.


This is a Giant Sea Star (Pisaster giganteus).  This species is found occasionally in the Bodega Head area, especially near the Spud Point Marina and the jetties at the entrance to the harbor.  Although we found these sea stars in the low intertidal zone, they're more common in deeper waters.  

The first two pictures highlighted the short, purple/pink spines surrounded by blue rings.  Spine color is helpful in differentiating juvenile and adult Giant Sea Stars.  Spines are pink/purple in juveniles and white in adults.  The other individual we encountered this morning was an adult (see below).  For scale, the juvenile above was ~12 cm across, while the adult pictured below was more than 15 cm across.




Thursday, April 25, 2013

Beechey

I took a quick walk around Moss Landing, California, this afternoon.  Although local residents are probably used to seeing these mammals, it was fun for me as they're not present on Bodega Head.


Note that there are three individuals in the photo above, two in the foreground and one in the background near the overturned wheelbarrow.  

Here's a close-up of the left-hand animal:


Although I don't have any resources with me tonight, and I have very little experience identifying ground squirrels, I think this is a California Ground Squirrel, also known as a Beechey Ground Squirrel (Spermophilus beecheyi).

Here are two additional views of the other individuals:



And one more of the left-hand squirrel, splayed out like a sphinx in the warm sun.


Wednesday, April 24, 2013

Tomcat

Tomcat Clover (Trifolium willdenovii)
photographed in the coastal prairie on Bodega Head, 24 April 2013


If you're wondering, this species was named after Carl Ludwig Willdenow (1765-1812), a German botanist known as one of the founders of the field of phytogeography (the study of the geographic distribution of plants).

Tuesday, April 23, 2013

The Nestler

I've heard that a lot of people reading the blog enjoy the mystery close-ups.  So here's a fun one:


The next image shows the entire appendage:


Did you guess crab claw?  Do you have any ideas about what type of crab?  That's much harder, but once you get to know this species, it's quite distinctive.

Here it is hiding in a crevice in the rocky intertidal zone:


This is a Granular Claw Crab (Oedignathus inermis).  Note that the two claws are dramatically different in size.  I've often wondered what they do with each claw, but it's not easy to find information about this crab.  The next picture isn't great, but it's the best I have right now for comparing the two claw types.


We don't find Granular Claw Crabs that often, but when we do, they're often nestled in narrow crevices or small depressions in the rock.  Recently Eric found a few deep within a mussel bed.  The individuals he discovered were gravid females — they were carrying embryos.

This female was quite protective of her developing embryos.  She carries them on the underside of her abdomen until they're ready to hatch into swimming larvae.


Below is a close-up of the embryos under the crab's abdomen.  If you look closely, you can see tiny lime green dots in some of the embryos.  I think these are the eyespots of the larvae.


One more view of this unusual crab, showing the shape of its carapace and the very broad, soft abdomen.


Monday, April 22, 2013

Pero

A trip out to get the laundry tonight resulted in a nice moth sighting in our yard in Sebastopol:


It's been very warm during the past couple of days.  It was about 67°F when I took this photo.  

I'm pretty sure this moth is in the genus Pero.  The Moths of Western North America says that there are 16 species of Pero in the West, but it only discusses and illustrates 4 of the 16, so I'm reluctant to try to identify it to species at this time.

Here are two close-ups of the wings.



 

Sunday, April 21, 2013

Still here

I'm posting a few quick images of this shorebird because it's approaching the late side for this species on the coast.  They tend to depart for inland breeding sites (e.g., grasslands in northeastern California) by late April/May.

 
This Long-billed Curlew was feeding on the tidal flats in Bodega Harbor (close to Doran Beach) on 21 April 2013.  

She often plunged her entire bill and head below the surface of the water.  (Females have longer bills than males, and this was a very long bill, so I'm guessing it was a female.)


A distant shot, and not quite in focus, but you can still appreciate the slightly different shapes of the upper and lower mandibles.


When identifying shorebirds at a distance, scale is important, and it's often useful to compare known species to each other to get a feel for relative size.  In the image below, the Long-billed Curlew is pictured with three other species.  (To give you a chance to identify them yourself, I'll wait until after the photo.)


One Marbled Godwit to the left side of the curlew, two Short-billed Dowitchers standing together at the lower left , and one Dunlin to the far right.


For more photos and a little more information about Long-billed Curlews, see the post from 15 January 2012.

Friday, April 19, 2013

Stiff-tailed

Especially when there are northwest winds, waterfowl often gather at the north end of Bodega Harbor.  Last night as we left work, we noticed some ducks close to shore.  The light was nice, so we decided to spend a few minutes watching them before heading home.

Many of the ducks were resting with their bills tucked in.  But the shape and position of the tail offers a helpful hint to their identity.  This species is a member of the subfamily of ducks known as stiff-tailed ducks.


A pair of Ruddy Ducks (Oxyura jamaicensis).


Here's a close-up of the male once he became alert:

Note the solid white cheek patch, black cap, blue bill, and rust-colored sides. 


For comparison, here's the female:

She has dark streak across her cheek, a brown cap, gray bill, and brown sides.


At this time of year, not all of the males have rusty sides and blue bills — some have yet to develop their full breeding plumage.  But you can still identify them by their solid white cheeks.

In the picture below, how many males and females do you see?



Answer: There are three males and three females.  From bottom to top: one male at bottom, then two females above him, then two males above them (rust-colored on left), and then one female at top.


In preparing for this post, I read in The Dictionary of American Bird Names that Ruddy Ducks used to be called "Jamaican Shovelers."  Jamaica because that's where one of the first specimens was collected, and shoveler because of the way they use their broad bills to sift food from the water (similar to Northern Shovelers).



Most Ruddy Ducks will leave coastal locations by about mid-May to nest at inland ponds and lakes with marsh vegetation.

Thursday, April 18, 2013

Queen of the Universe

Today I received an interesting e-mail from Alice about a bird sighting from Bodega Head on 17 April 2013:

"We saw a long string of big floating clumps of birds, probably around 500 individuals altogether, floating around offshore out in the kelp, drifting northwest with the winds, splashing around as they prepared to dive, and reappearing again in with their neighbors.  These birds appeared to be brown, not black or black and white.  The binocs didn’t give us any details at all.  I know this isn’t much to go by, but we thought we’d see if you know what we’re talking about.  Any thoughts you might have would be helpful.  If you are able to tell us what they were, that will make you the Queen of the Universe!"

Queen of the Universe!  Now how could I turn that down!  ;)

In this case, there are two things going for us.  Alice explained the setting, provided a general description of the birds and their behavior, and recounted the numbers involved — all important.  I spent a few minutes looking offshore myself on April 15, just two days before, so I have an idea of which species might match this description...and, just by chance, I took photos.  Perhaps I can be Queen of the Universe!

Here's a distant photo of a large raft of small brown birds.


Next I'll zoom in so you can see some of the field marks.  


Note the small size and compact body; short, thin bill; peaked head; dark neck and back blending into beautiful chestnut-colored sides and flanks.  On some birds you can see what looks like a bright golden patch on the side of the head.  These are the golden "ears" of the Eared Grebe (Podiceps nigricollis) in breeding plumage.

Here's a photo that shows some of the diving behavior.  The grebes almost look like porpoises in this picture!


And I can't help including one more image.  When I was reviewing the photos, I was surprised to see the feet of many of the grebes in the next picture.  Their feet are positioned very far back on the body, so look for them trailing behind (especially on birds near the center/right of the photo).


So, after Alice sees this post, I'll have to find out if she thinks she saw Eared Grebes yesterday.