Songs of The Cedars

We'll wrap up The Cedars Series with a few miscellaneous shots:

 

An ultrabasic spring (pH > 11) where calcium carbonate is a byproduct of serpentinization.  [Serpentinization as defined by Roger Raiche = "a process where igneous ultramafic mantle rock (peridotite) is metamorphosed into secondary serpentine minerals.]

A water strider (and its more obvious shadow) on the surface of the pool downstream from the spring:

 

Mineral Falls (~20-feet high):

 

At the top of the falls, I couldn't help exclaiming, "What sedge is that?" upon encountering this showy inflorescence:

 

When David answered that it was Cotton Grass, I smiled, and thought to myself, "Of course."  I recognized the genus from seeing it in New England and Canadian bogs, but hadn't seen it yet in California.  Be forewarned: the first half of the common name is accurate (it does look like cotton), but the second half is misleading, i.e., it's not a grass.  Perhaps it should be called Cotton Sedge?  [This is Calliscirpus criniger, formerly Eriophorum criniger.]

And one more image from The Cedars, although I wish I had an audio recording to share.  Some of you know how much I appreciate listening to the sounds of landscapes.  While listening to The Cedars, the sounds I will remember most will include the piercing scream of a Peregrine Falcon, the distant call of a raven...and the most common sounds — running water, sometimes close, sometimes far, running over rocks...and singing Black-throated Gray Warblers (Setophaga nigrescens).  I like thinking about their songs carrying across that open landscape, connecting the stands of cypress trees on the slopes and in the ravines.

 

The unexpected

There are lots of things to like about walking beaches, but one of the most enjoyable is encountering the unexpected.  While walking Salmon Creek Beach this afternoon, I started seeing beetles washed up in the wrack line.  And not just a few beetles, but thousands of beetles!  It was pretty phenomenal.
 
Most of the beetles looked like this (see next image).  It might be a Spotted Cucumber Beetle, but I don't have much experience identifying this type of beetle, so please let me know if you are familiar with this species.

 

When I started looking more closely, I realized there were other species involved.  There were quite a few ladybugs, or ladybird beetles (see below for one example).  And a smaller beetle with mottled orange and brown markings (also in the image below).

 

And a wonderful weevil:

 

And there were true bugs, too!  Check out this intense metallic green bug:

 

And a bright orange stink bug (upside down, with wings open):

 

 And a treehopper with a rounded red horn (placed on a Bull Kelp float for a photo)!

 

And then I was more than surprised to see a backswimmer washed ashore!  They're normally in freshwater ponds, but they can fly, so it must have been caught offshore and then washed in by the waves.

 

And then this water strider, too!

 

Okay, I think you're getting the idea that there were a lot of insects washed up on the beach today.  I'm just showing a few of them, but there were also bees, wasps, flies, butterflies, moths, and more.  

I'm not quite sure what happened to all of these animals.  Perhaps they were dispersing during the warm weather, drifted too far offshore, then got caught in the strong winds during the past couple of days, blown onto the surface of the ocean and then washed up onto the beach.  Do you have other ideas?

Upside down

 

Backswimmers were also common at the shallow pool in the dunes where we saw the clam shrimp (see yesterday's post).

Although it might be hard to tell because the water was so clear, in all of these pictures the backswimmers are completely submerged, floating upside down at the water's surface.  (All of these individuals were between 1-1.5 cm long.)

Note the extremely long oar-like hindlegs that are fringed with hairs, an adaptation for swimming or rowing.  In the view below you can see the raptorial forelegs tipped with claws.  They use them for capturing and holding prey.

Backswimmers are active predators, detecting their prey visually and through vibrations.  They have two large compound eyes that can focus both horizontally through the water and at an angle towards and above the water surface (see photo and diagram below).

 

 

Adapted from Schwind, R.  1983.  Zonation of the optical environment and zonation in the rhabdom structure within the eye of the backswimmer, Notonecta glauca.  Cell & Tissue Research 232: 53-63.

Backswimmers eat a variety of prey (invertebrates and vertebrates).  We observed one with a small tadpole and another with a damselfly nymph.

 

In the photo above, the tadpole's head is close to the backswimmer's eyes.  The backswimmer is also holding a small snail (between the second pair of legs).  I'm not sure, but I'm guessing the snail had been floating and that the backswimmer was just using it as a place to rest.  (They often grasp vegetation or other floating objects.)

  

It was great fun watching them swim and following the ripples created by their powerful strokes.

 

 

 

P.S.  Although a different species, here is some amazing video footage of backswimmers swimming, laying eggs, and hatching.