8/8

Well, this is for anyone who might have a birthday on 8/8:

 

And here's a nice example of where this eight-armed animal might like to live:

 

(The photo above was taken along the Big Sur coast, but there are similar settings in northern California.) 

Is there anyone out there with a birthday on August 8th?  If so, raise your hand (or arm), and celebrate with a cephalopod!  ;)

 

A silken nest

Just a short little story about a caterpillar and its host plant.

If you ever come across a silken nest of everlasting or cudweed flowers...

 

...it may be a clue that there's an animal living inside:

 

I gently pulled aside a portion of this nest to expose the caterpillar within (but I closed it up again after I took these pictures). 

 

This is the caterpillar of an American Lady butterfly (Vanessa virginiensis).  It made a wonderful nest on an everlasting plant (Pseudognaphalium sp., formerly Gnaphalium sp.) in the Bodega Dunes.  The caterpillar binds the flowers and other plant material together to form a shelter.  It crawls away from the nest to feed on the plant's leaves.  I posted about American Lady butterfly adults previously, but this is the first time I've photographed a caterpillar of this species locally.

Drawn in

Here's another guessing game.  This is an extreme close-up, taken under a microscope:

 

A couple more views:

 

 

Some of you may have guessed this animal already.  If not, be forewarned. The next image may give it away:

 

And here's another with the foot extended over the tip of the shell:

 

This is a Lewis's Moon Snail (Neverita lewisii, formerly Polinices lewisii or Euspira lewisii).  Joe kindly let me photograph this small individual that he discovered locally.  It was only ~2 cm across.  

Moon snails occur on the tidal flats in Bodega Harbor, and occasionally in subtidal sandy areas offshore.  They're active predators that feed on clams (by drilling a hole through the shell!).

The first few photos highlight the long tentacles, extended above the sand as the moon snail explored its surroundings.  In the third photo, you can also see the siphon, outlined in black (in the upper right corner).  Water is pulled into the siphon for respiration and sensing of the environment.

There's something about the design of moon snail shells that just draws you in.  

 

Georgia O'Keeffe chose moon snails as subjects for several of her paintings.  The San Diego Museum of Art owns one called Pink Shell with Seaweed.  You can see an example of that painting here.  

Little spaceships

Can you guess what this is?

 

I can provide a few clues.  It's very small, only a couple of millimeters long.  It's marine (this picture was taken while it was under water).

Here's another individual (below).  [The yellow/orange area is the stomach.]

 

Need more clues?  It's the larval, swimming stage of a familiar invertebrate found along rocky shores.  It doesn't really look anything like this once it undergoes metamorphosis into a juvenile form.  But all of the stages (larva, juvenile, adult) have arms.

 

This larval stage will swim and feed in coastal waters for ~45 to more than 60 days.  The individuals in these pictures are 39 days old.  Once they return to shore and metamorphose into juveniles, they'll have five arms and a water vascular system that supports tubefeet for locomotion.

 

Do you have a guess now?

The answer is in the very next picture!

 

Yes!  These are larval Bat Stars (Patiria miniata) — the stage in the pictures above is formally called a bipinnaria larva.  Aren't they wonderful?  Many people have encountered these adult sea stars in local tidepools, but are unfamiliar with the early life stages because they are microscopic.  Welcome to the amazing world of larval sea stars!

A brief stopover

Juvenile Baird's Sandpiper (Calidris bairdii), photographed on 3 August 2013.  Baird's Sandpipers are uncommon fall migrants in the Bodega Head area.  This is just a brief stopover site for them; they'll spend the winter in South America.  (Hard to believe, but some individuals complete the 15,000-km journey from Alaska to Tierra del Fuego in 5 weeks!)

Salmon Creek Beach and Bodega Harbor are good places to look for Baird's Sandpipers.  Note the buffy head and breast, white-tipped back feathers, long wings (projecting beyond the tail), and black legs.

 

 

 

 

 

Turrets and tongues

I can't help it — here's another local bee story.  I've actually been meaning to post about this one for a while now, but have been caught up with a variety of other things since Phil Van Soelen wrote to me about these bees in June.  

 

Colonies of Anthophora bomboides stanfordiana are observable from the outer parking lot on the southern end of Bodega Head.  What you might notice first are the fairly long "turrets" at the entrances to their burrows in the cliffs.

 

And then you'll see the bees approaching the burrows, or the faces of the bees peering out from the burrow entrances (below).

 

The turrets themselves are very intriguing.  At least three theories have been suggested for why the bees build them: deterring fly parasitism, protection from rain or debris, and serving as landmarks for orientation.

To build the turrets, the bees must find a water source, carry the water back to the cliff, and then mix the water with the sediment to create mud which they'll mold into a turret.

At one colony site, I found the bees at a very small pool of water on the upper portion of the beach.  Here they were busily sipping water:

 

When I looked closely at these pictures, I realized something about bees that I should have known a long time ago.  Bees have tongues!  In the next image, look for the bee's brownish tongue curling under to pick up water.  [Once you've seen it in the picture below, I think you'll be able to see at least two of the tongues in the photo above, too.]

 

There's so much to learn about the bees of Bodega Head!

 

A significant investment

I'm excited to share some more information about the bees in last night's post.  I sent the pictures to Robbin Thorp at UC Davis and he kindly identified them as Melissodes pallidisignata.  And it turns out that Robbin studied this species at Point Reyes in the 1960s.  He was able to answer many questions about this fascinating native bee.

One thing that I didn't reveal is that there were other bees nearby that looked very different than the bees I showed last night.  Instead of being mostly brown and black, they were much paler overall with fuzzy white hairs, green eyes, and long antennae (see below).

 

 

Occasionally, these paler bees would "attack" the browner bees that I described last night.  See the next two images for examples of action shots:

 

 

Because I didn't know any better at the time, I thought the paler bees might be a different species and that they were exhibiting territorial behavior.  

However, Robbin has confirmed that both the paler individuals and the browner individuals are Melissodes pallidisignata — the paler bees are males and the browner bees are females.  So the "attacks" I observed were more likely males trying to mate with females.

Here's one short sequence that was intriguing.  A male flew in towards a female who then lifted her hind legs (covered in pollen) vertically.   

 

Below, the male flew off and the female went back to digging.

 

But about 10 seconds later, he (or another male?) returned and this time made contact with the female.

 

Robbin also was very generous in sharing information about the life history of Melissodes pallidisignata. When a female burrows into loose soil, she is accessing a previously excavated burrow with a nest chamber (review the post from 31 July 2013).  She'll deposit only one egg per chamber and provision the chamber with pollen (which will take several trips!).  A female may stay underground for up to 15 minutes and then emerge to go on another trip to find more pollen.  It's a significant parental investment!