A busy Sunday afternoon

After Sunday chores, I took a short walk at Sonoma Valley Regional Park (in Glen Ellen).  There was a lot of breeding bird activity, and insects were visible in sunny spots.  [It reached 90°F in Cotati today!]

Here's a selection of images to represent the walk:

 

Juvenile Bewick's Wren (Thryomanes bewickii) — note the shorter bill with yellowish color at the gape

 

Oak Titmouse (Baeolophus inornatus) with a bright green caterpillar in its bill (it flew into a nest hole with it, likely to feed young) 

 

Pipevine Swallowtail (Battus philenor) nectaring on Dichelostemma

 

Mournful Duskywing (Erynnis tristis) — look for the prominent white edges on the hind wings

 

Unidentified robber fly (Asilidae) with amazing metallic orange eyes!  Robber flies are sit-and-wait predators that feed on other insects.  (If you are familiar with this species, I'd love help with the identification.)

Although not from today, here's an older picture of a different robber fly.  It had just captured a butterfly in the Bodega Dunes (photographed 18 August 2010):

 

Two days after the wind

 

Ocean colors from the coast to the horizon during very calm conditions on 16 April 2016 

(two days after strong northwest winds)

After the wind

The Pacific Ocean after a windy night (photographed 15 April 2016)

Passing by

 

Passing squall on the horizon, 14 April 2016 

 

Peregrine Falcon overhead

"Spiky Yoda"

While walking Salmon Creek Beach on two days earlier this month (2 April and 6 April 2016), we looked down to see a few of these distinctive gelatinous bits on the sand:

 

Although they looked somewhat similar to the nectophore (swimming bell) of a siphonophore that we found last year (see post about Hippopodius on 16 April 2015), they were also quite different in that they had prominent points (especially out to the sides) and abundant little "spines," making them look very spiky.

For scale, here's a photo with Eric's finger.  This nectophore was ~15 mm across.

 

To fully appreciate the gelatinous spines, here's a view under the microscope:

 

Meet Vogtia spinosa!  This is the first time we've found this species washed up on the beach.  Usually they live offshore and at depth (often 300-500 meters below the surface).

Unfortunately, I've had trouble finding pictures or diagrams of the entire animal.  I've read that Vogtia is arranged similarly to Hippopodius, so check out the diagram on my previous post to start visualizing what Vogtia might look like.  To clarify, what we found on the beach is a single nectophore — when the animal is whole, there might be up to 16 nectophores positioned next to each other along a central stem.   

I can't resist showing one more picture.  Below is the Vogtia nectophore on Eric's thumb.  For some reason, it's shape reminded me of Yoda, so before I identified this siphonophore to species, I casually called it the "Spiky Yoda" nectophore.  What do you think?  Do you see Yoda, too?  ;)

 

Comparing two sea snails

I have a long list of things I've been meaning to post, so I'm going to check one of them off my list tonight.

Remember the Violet Sea Snail (Janthina janthina) that I showed on 16 March 2016 (see post here)?  I thought it would be useful to post better pictures of its shell, especially in comparison to the related Purple Sea Snails (Janthina umbilicata) shown in January and February 2016.

Here's the first photo of the Violet Sea Snail (Janthina janthina), showing the view with the aperture (opening) of the shell facing up:

 

And here's a view from the opposite side:

 

Note how pale Janthina janthina is, especially on the topmost whorls.  Also examine the shape of the striations (lines) on the shell.  They bend gently (in a U-shape) along the center of the largest whorl.  We'll compare these lines in both species soon, but first here's another view of these two features (the paleness and the rounded lines):

 

To compare Janthina janthina with Janthina umbilicata, I'll show them in the same position.

 

So here's Janthina janthina:

And here's Janthina umbilicata:

Now you can compare several different features:

(1) the height of the spires.  Note that the spire (topmost whorls) is much lower in Janthina janthina — it appears flattened in comparison with the taller spire in Janthina umbilicata. 

(2) the shape of the striations.  Look for the gently rounded, U-shaped striations in Janthina janthina.  Compare that shape to the strong angled V-shaped striations in Janthina umbilicata.  (Follow the striations from the top of the whorl down towards the bottom.)

(3) a keel in the center of the largest whorl.  Janthina janthina lacks a keel in the center of the largest whorl — you only see the striations. While Janthina umbilicata has a noticeable keel — in the photo above, it looks like a zipper running through the center of the whorl (located at the bottom of the "V").

Janthina janthina appears to be quite rare in northern California, but now there's a pretty good record of this shell and you'll know what to look for to separate these two species if you are lucky enough to find a sea snail in the future!

Pausing to preen

I went for a short walk in the neighborhood before dinner.  It was relatively quiet, and then I heard one of my favorite birds calling, a Brown Creeper (Certhia americana).  

I listened carefully, and tried to follow the sound.  Brown Creepers are usually pretty active, searching for food along tree trunks and branches.  Watching for their movement is a good way to find them. Because they call while foraging, the sound usually moves around with them, but this time the call note kept coming from the same location.  Eventually I spotted the bird that was calling:

 

Instead of feeding, this creeper was actively preening.  It caught me a little off-guard — I couldn't immediately recall seeing a creeper preening before. 

Later I read in the Birds of North America that preening in Brown Creepers has not been described in detail.  It was hard to photograph, as the bird was perched in a shadowy place, but here's one image for the record:

 

I watched this Brown Creeper preen for ~4 minutes.  Then it started to search for food along the trunk.  It continued to give call notes, apparently keeping in touch with another creeper nearby.

I started wondering about why it might be difficult to observe creepers preening.  I'm guessing it's not because they don't preen that often.  Do they preen in more out-of-the-way places?  Or at times of day when we're less likely to see it?  Are they usually still and quiet when preening, and therefore harder to spot while blending in with the bark? 

 

P.S.  Click here for some nice pictures of a creeper posted on 5 October 2012.