Silflay

 

We came upon this Brush Rabbit (Sylvilagus bachmani) feeding along the edge of the Pinnacle Gulch Trail during the late afternoon on 30 November 2013.  Although I've thought about posting about this species before, I haven't managed a good picture yet.  Today I can't resist for a few reasons.

(1) I learned something about what Brush Rabbits eat.  I mentioned the rabbit was feeding.  We could see that it was nibbling on something.  After it had hopped away into the vegetation, I went over to evaluate what it had been eating.  I wasn't certain, but it looked like the grass blades had been clipped.  Later I read this about Brush Rabbits:

"Edible grasses are by far the most important food for the Brush Rabbit throughout most of its range." (Orr 1940, as quoted in Chapman 1974) 

The article went on to say that when clovers were available, they were preferred more than all other plants.

 

(2) I learned that Brush Rabbits are crepuscular.  They're most active between ~6 a.m. and 10:30 a.m. and then between sunset and 2 a.m.  When they're not active, they spend a lot of time resting or basking in their forms (a form is a cleared shelter in the brush about the same size as the rabbit). 

(3) Tomorrow is the first day of December, and in some places it's a tradition to say "Rabbit, rabbit, rabbit" out loud upon waking to bring good luck for the rest of the month.  So, here's a reminder to say your rabbits!

 

P.S. Do you know how a book sometimes stays with you forever?  Watership Down comes up in my life frequently.  Whenever I see a rabbit feeding like this, the word "silflay" is the first thing I think of.  In Watership Down, silflay is a term used to describe when the rabbits leave their burrows to feed; it can also be translated as "to eat outside."  I had a friend who also knew this book well and we would enjoy picnics together, so we would say to each other, "Want to silflay?" 

Helmuts or Kisses?

We spent a little time tidepooling at Point Reyes this afternoon.  Eric came across a few clusters of snails that appeared to be laying eggs.  In the picture below, there are at least 5 snails on a blade of kelp.  The snails are surrounded by densely packed egg capsules.

 

The snail is a Variegated Amphissa (Amphissa versicolor).  [Unfortunately, this isn't a great example of this species because these individuals are covered by a bryozoan so their true shells are hidden.]  

Here's a close-up of the egg capsules on the right side:

 

From this angle you can see that the capsules are two-parted.  There's a rounded basal portion attached to the kelp, and an upright vertical section that looks like a very tall cap.  These capsules are sometimes described as helmut-shaped, but they often remind me of Hershey's Kisses!

The developing embryos are in the rounded basal portion.  You can see them when viewed from above (next image):

 

Eventually the embryos will hatch out as swimming larvae and will develop in the plankton for a while before returning to shore and undergoing metamorphosis into crawling juvenile snails.

Thank you

It's hard to believe that it's been two years since I started this blog...and that I've been posting almost every day since!  When I consider how that's even possible, I think about you and how thankful I am for such a wonderful community of naturalist friends and colleagues and enthusiasts.

I'll admit that sometimes when I sit down to put together a blog post after dinner, I'm tired and I'm not sure I'll be able to pull it off.  But it's you that inspires me.  I know you're waiting, wondering what might come next, and that spurs me on.

So many of you have contributed to this blog in so many ways.  You've helped identify organisms that I couldn't.  You've asked questions about local plants or animals that forced me to delve deeper.  You've submitted comments or e-mails that made me laugh.  And have told me about resources to assist with my research.  You've written to say how much the pictures mean to you, how they've shown you a world you didn't know existed, or reminded you of a place that you love.

All of this encourages me, and all of this makes the blog so much better than if I was doing it by myself.  Together we've done great things, and for that I am truly thankful!

I would also be remiss if I didn't thank the organisms themselves, and the landscapes and seascapes of Bodega Head.  We're so lucky to live in such a beautiful and fascinating place!

Here's one of my favorite local marine snails.  It's called an Appleseed Erato (Hespererato vitellina, formerly Erato vitellina).  It's small, ~1 cm long — a wonderful reddish color, with a smooth, polished surface.  The last image will reveal the origin of the common name in the snail's likeness to an apple seed (kind of random, but I thought of it tonight because I'll be eating some apple pie tomorrow!).

 

 

 

Happy Thanksgiving!

Another Summer record

Well, these are distant shots, but it seems worth posting them as this is a bird that's only been observed about a dozen times in Sonoma County.

 

This Summer Tanager (Piranga rubra) appeared at Campbell Cove yesterday and was also observed today (when I photographed it).

Although Summer Tanagers breed in the southwestern portion of the country (including southern California and Texas), this bird is thought to belong to the subspecies that breeds in the eastern portion of the country (smaller size overall, shorter bill, shorter tail).  

Here's another view while perched in a willow:

 

According to the Birds of Sonoma County California, it looks like there are only 3 other Summer Tanager records for the Bodega Head area: 28 May 1985, 10-16 October 1988, and 4 November 2008.

Summer Tanagers are neotropical migrants, breeding in North America and wintering in Central America and northern South America.  The individuals that show up here have strayed off course.

P.S.  For anyone interested in the shark pictures last night, it turns out that it was a Soupfin Shark (Galeorhinus galeus) and not a Brown Smooth-hound Shark.  I'll correct that post soon.

Smooth-hound?

Yesterday, 24 November 2013, County Park staff flagged me down to report a shark that had washed ashore at Doran Beach.  Although no longer alive, it was still in pretty good condition, so here's a picture:

 

The shark was ~5 feet long.  The next image shows a better side profile:

 

Note the relatively long snout and large eyes:

 

And the interesting shape of the tail fin:

 

Park staff had wondered whether this might be a Brown Smooth-hound Shark (Mustelus henlei).  Some of the characteristics seemed like a good match for that species, but there are a few others that I'm not quite sure about.  

For example, the maximum size listed for Brown Smooth-hounds is ~3.2 feet, so this shark appears to be larger.  And I don't know how consistent tail shape is in this group of sharks, but when I compared pictures of Brown Smooth-hound tails online, this individual's tail was different enough for me to hesitate.

So now I'm going to have to ask for help.  Are there any shark experts out there who can assist with this identification?  I'll circulate the photos and will report back if anyone offers additional ideas.

At least two species of smooth-hound sharks (Gray and Brown) are known to occur along the West Coast from northern California down to the Gulf of California.  Brown Smooth-hound Sharks are apparently common in shallow water bays such as Humboldt, Tomales and San Francisco bays.  Gray Smooth-hound Sharks (Mustelus californicus) occur in bays and along rocky shores.  For the record, Gray Smooth-hounds do get larger than Browns (up to at least 5.3 feet).

There is more information about both of these sharks on this California Department of Fish and Wildlife web page.

ADDENDUM (6 December 2013): Sorry it's taken me so long, but I need to update the identification of this shark!  Several experts have confirmed this as a Soupfin Shark (Galeorhinus galeus).  I had started to wonder about this when I checked Bay Fishes of Northern California (Bane and Bane 1971) because they mentioned that small Soupfins could look similar to smooth-hounds...and several of the characters looked right.  So a Soupfin Shark it is!

June and November

This is just a quick follow-up to a post in June (see "Color in the strand").  And it's a lesson in breaking out of familiar patterns.  I often look for Pink Sand Verbena flowering during the summer. But until this past week, I had no idea that its flowering season extended into November!

On 21 November I happened to walk by an area where some of the plants grow at Doran Beach and many of them were in full bloom.

 

Seeds were developing on many of the plants, but I was surprised at the number of flowers that were visible in late November.  Perhaps it's typical for this species and I just hadn't noticed it at this time of year before.  Or maybe the peak in its flowering time varies from year to year depending on growing conditions?  You'd have to have much better records than I do to know the answer, but it's fun to wonder about.  And it sure was nice to see it in both June and November!

 

On their way to the desert?

In the last post I mentioned some interesting bird sightings from Doran Beach on 21 November 2013.  That's not the only thing that caught my eye that day.  As soon as I started walking onto the beach, I noticed butterflies flying by — coming in off the water or flying parallel to the shore. 

It seemed late in the year for a notable butterfly movement along the coast.  But when I left Bodega Bay and felt the very strong offshore winds that were especially apparent inland, I wondered if the weather conditions had something to do with dispersing butterflies showing up along the shore.

Some of the butterflies would land on the sand and start to bask in the sun:

 

Others would bask on upper beach plants:

 

The view above displays the characteristics of a Painted Lady (Vanessa cardui).  [For more about how to identify this species, see this post from last October.]

Many of the butterflies were stopping to nectar on flowering Sea Rocket (Cakile maritima):

 

 

In a Field Guide to Butterflies of the San Francisco Bay and Sacramento Valley Regions, Shapiro and Manolis write that Painted Ladies overwinter in deserts along the U.S.-Mexico border and then move northward in late winter and spring (e.g., late February-late April).  They breed along the way, and their offspring move further north.  Southbound individuals appear in our area in late August and "may straggle even into early December."

So from this picture of their life cycle, the butterflies observed along the coast this past week are probably late southbound migrants on their way to the desert.  Indeed, some of them were quite tattered and I wonder if they'll make it to their final destination (see below)?

 

I don't know if other people have kept track of the phenology of southbound Painted Lady movements along the coast, or whether it's tied to offshore winds, but I'd love to hear back from other folks with more information. 

High in the sky

I had to go home sick today, but I decided to make a quick stop at Doran Beach on the way (for a little fresh air and to get rid of all of those bad germs before being stuck indoors for the rest of the day!).

As soon as I stepped out of the car I knew it was "one of those days."  There are some days when you just can't miss...when it seems like everywhere you look there's something to see.  I was both excited and disappointed, as I was only going to be there for a short time.  But sometimes it only takes a few minutes to make a handful of interesting observations.

The first thing that happened — I heard a familiar call overhead, but one that I don't hear often in Bodega Bay.  Snow Geese!  The sky was blue, blue, blue today, and the birds were very, very high, which made it difficult to find them at first.  But I kept following the sound and searching the sky and eventually I located the flock:

 

I took a few different pictures and when I reviewed them and tried to count the number of individuals in the flock, I realized it was an interesting lesson in counting.  The configuration of the flock really makes a big difference in how easy it is to count.  Below are two more examples of this same flock.  

Try to count (using the photo above and the next two below — you can click on them for larger versions); consider which formation works best for you; and see how many Snow Geese you come up with (my answer is below the pictures).

 

 

I came up with 47 Snow Geese.  I liked the last configuration the best.  It was easy to count the front row of geese and then there were just a few isolated groups behind them.  The middle picture was second best for me as the flock was divided into smaller groups of geese that were relatively isolated and easy to count.  The first picture was the hardest.

The next thing that happened: I heard a high-pitched shriek and looked up to see two Peregrine Falcons diving at each other.  Fun!  And then something else caught my eye above them.  Swans!

 

Swans are rare in Bodega Bay.  Based on their long straight necks, black bills, and likelihood of occurrence, it's probable that these were Tundra Swans.  

Because this was a flyby sighting, it was hard to see field marks on the birds.  Size is a useful character when trying to separate Tundra and Trumpeter swans.  These swans were isolated in the sky and I didn't have anything to compare them with, so all I had to go on was my impression of their size in comparison to other familiar birds.

Tundra Swans have a wingspan of 66 inches, while Trumpeter Swans have a wingspan of 80 inches.  For comparison, the closest birds to Tundras in this area are Turkey Vultures (67 inches) and Osprey (63 inches).  At the other end, closer to Trumpeters, you could use Brown Pelicans (79 inches) and Bald Eagles (80 inches).

These swans didn't seem that large to me, so I'd lean towards calling them Tundra Swans.  But those of you who know me know how conservative I am when it comes to identifying things.  Unfortunately, although it's tempting to call them Tundra Swans, I'll have to say that I didn't see enough to identify them with 100% certainty.

 

Pink and silver stripes

A close-up of another critter that I encountered in the rain last night:

 

The next view shows the head, with dark eyes and segmented antennae:

 

This is a very large millipede with wonderful pink and silver stripes.  I'd estimate it was ~2.5 inches long (7 cm) and ~1/4 inch (0.6 cm) in diameter.

 

While trying to identify this millipede, I found an Annotated Checklist of the Millipeds of California published by Rowland Shelley in 2002.  Do you want to guess how many species and subspecies of millipedes there are in California? (The answer is below the next image.)

 

There are 226 species and subspecies of millipedes in the Golden State.  Whew!  That's a lot of millipedes (and a lot of little legs running around California!).  

Unfortunately, the list didn't help me identify this particular millipede, so if you know which species it is, please don't hesitate to contact me.

Finally, some rain!

 

And I think just about everyone and everything was enjoying the rain today.  

We left work a little late, and encountered a couple of California Red-legged Frogs (Rana draytonii) in the dark, wet night.

Red-legged Frogs are not common on Bodega Head, but occasionally are reported dispersing during rainy conditions.  We watched very carefully to make sure they made it safely across the road.

 

I've always loved looking into frogs eyes.  It's like gazing into another galaxy, with swirls of pearlescent patterns floating over deep black backdrops.  I don't know why their eyes are so beautiful, but I'm very thankful for the chance to admire them every now and then.

Small wonders

Time for another mystery close-up.  This is a tough one!

 

These pictures were taken at very high magnification under a microscope.  I'll zoom out a little more for a slightly broader view:

 

And here's another picture that's very similar, but from a slightly different angle (below).  

Any guesses yet?  The long feathery structures (tentacles) may be a helpful clue.

 

I can also tell you that both the tentacles and the unusual funnel-shaped pod that's filled with tiny objects with red spots can be withdrawn into a calcareous tube (visible as a white blur in the background).

The next image will give the answer away, so only look further if you're ready.

 

These are small spirorbid tubeworms.  Their feathery tentacles are fanned outward when feeding (capturing plankton from the water).  Spirorbid worms have a funnel-shaped operculum that seals the opening to their tubes when the worm pulls in.  In some species, including this one, the operculum doubles as a brood chamber for their embryos!

The tiny objects in the operculum with red spots are developing embryos.  The red spots are eyespots (two per embryo).  The embryos will develop in the operculum for ~2-4 weeks (depending on the species and water temperature), and then will hatch as larvae and swim briefly before settling down to form their own tubes.

Here's another example of a tubeworm with extended feeding tentacles and an operculum filled with embryos.

 

If you've spent some time near the shore, you've probably seen spirorbids, but you may have walked by them without a second glance because of their small size (only a few millimeters across).  But they're quite common on rocks and seaweeds (or hard-shelled animals such as mussels and snails) and sometimes occur in dense patches:

 

On 6 February 2012, I showed pictures of a different species of spirorbid from Bodega Head (see those images here).  I'm still trying to work out the identification of spirorbids that live in this region, so we'll have to update you as we learn more.  For now I hope you enjoyed learning a bit about their life history!

Fastest digger in the West

Think of the fastest digging animal you know of.  Now let me introduce you to an animal that might be faster. This is Amphiodia occidentalis, also known as a Long-armed Brittle Star.  

 

Eric found it under a rock in the low intertidal zone on Bodega Head.  After we identified it as Amphiodia occidentalis, we read this about it:

"...burrowing behavior is spectacular and is easily seen if an animal is placed on fine sand under water." 

Who could resist that?

Because this behavior is better appreciated through video, we're providing an action clip below.  Before you press play, keep two things in mind.  (1) It's tempting to focus on the central disk, but most of the action is happening along the arms.  So it's worth trying to watch the arms and to process how fast they are disappearing below the sand.  (2) We've actually done something a little unusual with this video — it plays forward and then in reverse (all in actual time, not sped up!).  We found that the brittle star disappears so quickly it's hard to understand what happened; seeing it in reverse somehow reminds you just how fast the arms sink below the sand.  [If you're reading this in an e-mail, you may need to click on the title of the post above to access the video on the web page.]

Amphiodia Blog from Jackie Sones on Vimeo.

Once buried, only the tips of the brittle star's arms remain above the surface for suspension feeding.

Here's a close-up of Amphiodia under the microscope:

 

It's hard to see them, but the amazing burrowing behavior is made possible by tubefeet located on the underside of the arms.  The tubefeet are long and flexible, and when they bend to kick up sand they fit neatly between the arm spines.

Because the tubefeet are transparent it was difficult to photograph them, but I've highlighted two of them with red arrows in the image below.  The upper arrow is pointing to a tubefoot that is bent and in the process of flicking upward.  The lower arrow is highlighting an extended tubefoot; note the smooth texture at the base (close to the arm) and the rough texture at the tip.

According to Intertidal Invertebrates of California, Amphiodia occidentalis may be found in a variety of habitats: under rocks in sand, in protected tidepools, near the roots of eelgrass, or in kelp holdfasts.  If you're lucky enough to find this brittle star, be sure to watch its magical disappearing act!

Here for the winter?

I've been wondering if one of these might show up and spend the winter on Bodega Head again:

 

I heard this Blue-gray Gnatcatcher as I was walking through the Bodega Dunes today (16 November 2013).  

I didn't get great photos, but here are a few for the record.  This bird was actively elevating and flaring its long tail, providing views of the white outer tail feathers.

 

The gnatcatcher was feeding mostly in Coyote Brush (Baccharis pilularis), Bush Lupine (Lupinus arboreus), and California Goldenbush (Ericameria ericoides), sometimes hovering briefly while snatching at insects.

 

I wrote about gnatcatchers last November, so if you'd like to learn a little more about them, you can review that post here.

Shhhhh...

...the oystercatchers are sleeping (well, most of them are).

 

Tonight I went to a talk about birds that might be affected by climate change.  Black Oystercatchers were on the list, so I decided to post some pictures of them, along with the coastal habitat they depend on.

Can you find the oystercatchers in the following pictures?  (There's one in each picture.)

 

(Above, the oystercatcher is in the middle of the picture and off to the right side.)

 

(In this one, the oystercatcher is in the center at the very top of the rock.) 

Although taken in different years, all of these images are from Bodega Head.

Remembering

Has anyone else been missing the little octopus whose development we followed from July through October?  I got used to checking on them every day, so part of me keeps thinking about them.  For anyone else out there who has "octopus withdrawal symptoms," here are a few images from the last individuals that hatched in mid-October.

Check out those chromatophores!  Some large, some small.  Some round, some angular.  Some on the upper surface, some below.

 

In the next photo, you can see one of the gills pretty clearly.  Look for the ladder-like structure hanging in the lower left portion of the mantle.

 

Most of the octopus showed predominantly red pigments.  But a few were noticeably yellow (see especially lower animal in next image), and eventually I learned that I could track these individuals easily.

 

Who knows if we'll ever get to see octopus of this size again, but I'm glad to have a few pictures to remember what they were like!

P.S.  For anyone who missed them, earlier parts of this story are here (hatching) and here (development).