September day

 

 

Phippsburg, Maine, 14 September 2023

 

Side by side

 

 

A couple of days ago I noticed a few shorebirds in the distance on the rocky shore.  At first I thought all three were going to be Wandering Tattlers (Tringa incana), but with a closer view I could see that one of the birds looked different.

You can compare the two species in the photos above and below.  Note the shade of gray, the amount of pale feather edging, the facial markings around the eye, and the bill length and thickness.  In the photo below you might also be able to compare the leg color.

 

 

 

I usually encounter Red Knots (Calidris canutus) on the tidal flats in Bodega Harbor, so I haven't seen these two species side by side very often. 

The Wandering Tattler is darker gray, shows more subtle pale feather edges (so looks less "scaly"), has more substantial white markings encircling the eye, has a slightly long and thicker (less tapered) bill, and has yellower legs.

The Red Knot is paler gray, has extensive pale feather edges (so looks very "scaly"), has more subtle markings around the eye (but does have a dark line through the eye and pale line above the eye), has a slightly shorter and more tapered bill, and has greenish-yellow legs.

Now I'll show one photo of each so you can guess which is which:

 

 

 

 

 

Nicely done!  The first of the two photos shows a Red Knot and the second shows a Wandering Tattler.  Both of these birds are juveniles. 

Although knot so obvious from a distance, now that you know what to look for, it will be easier to help anyone who is wandering how to tell these juvenile shorebirds apart.  ;)

Porpoising lions

  

Recently I've been getting quite a few questions about small groups of marine mammals observed swimming near shore off Bodega Head.  They're moving so quickly that it can be hard to make out different features.  But most of the time these are likely to be California Sea Lions (Zalophus californianus) porpoising at the surface, as shown above.

In photos, you can make out that they're sea lions pretty easily, but as they're swimming by sometimes you'll only see a smooth dark back, so it can be confusing.

Sleek sea lions swimming swiftly at the surface!

A flash of green

 

 

At work today I looked out the window and noticed a small bird flitting around in a lupine bush.  I could tell it wasn't a sparrow, but wasn't sure what it was, so went to get my camera and then stepped outside for a closer look.  

 

As I approached the shrub I noticed a flash of bright green and then this young Chestnut-sided Warbler (Setophaga pensylvanica) appeared.

 

The weather was good for seeing migrants today, so I wasn't totally surprised, but it was a nice view!

 

Transequatorial migrants

  

We were about to start a meeting this afternoon when we noticed a dark mass just offshore — thousands of Sooty Shearwaters (Ardenna griseus) in a very dense flock!  [I recommend clicking on the images for larger and sharper versions.]

Not long after, we started seeing lots of splashing:

 

 

The white splashes were large enough that at first I though there might be mammals in the area, too, or larger fish breaking the surface.  But with binoculars we could see that it was the shearwaters plunge-diving into the water.  I'm guessing there might have been bait fish (or squid?) in the area:

 

 

 

The birds were about 1/2 mile offshore, so the photos are distant, but below is a closer view where you can see some of the characteristic stiff-winged silhouettes of the shearwaters.  (By the way, I haven't counted, but scanning the photo below my guess is that there might be >500 birds in this photo alone.)

 

 

 

And one more photo showing the amazing density of the shearwater flock:

 

 

 

Sooty Shearwaters nest in the Southern Hemisphere (e.g., in/near Australia and New Zealand) and then fly across the equator to visit the North Pacific during their non-breeding season.  Take a look if you're out at the coast, it's impressive to see so many shearwaters at once!

Against the grains

 

 

Okay, so this post is a follow-up to last night's photo.  This shrimp is a master of camouflage, but here are a couple of photos (above and below) where it might be a little easier to see them because they're on the surface of the sand.

 

 

We've learned the pair of white spots just in front of the tail (on the 5th abdominal segment) are consistent enough that you can use them to locate the shrimp and orient to its tail and head ends.  Sometimes the white spots are merged into the shape of a heart.

 

The shrimp's coloration is remarkable — they match the sizes and colors of the surrounding sand grains and shell pieces so well that even when the shrimp was right in front of us it was often hard to see it.  The next two photos are a little more challenging, but I'm guessing you'll find the shrimp!  (Hint: You can also look for the narrow white stripes on the legs.)

 

 

 

 

 

We think this beautiful shrimp is Crangon handi, although we had to look more closely at several features to work through the identification (and see note at bottom of this post).  Some of these characteristics are hard to see in the field, but because we've noticed there aren't many Crangon handi photos online, Eric made this really useful guide to point out some important features (see below). 

 

Note the shape of the antennal scale, the shape of the claw on the cheliped (fancy name for a leg that bears a claw), and the three tiny spines that flank each side of the very tip of the tail (telson):

 

 

Drawings modified from Kuris, A.M. and J.T. Carlton (1977). Description of a new species, Crangon handi, and new genus, Lissocrangon, of crangonid shrimps (Crustacea: Carida) from the California coast, with notes on adaptation in body shape and coloration.  Biological Bulletin 153: 540-559.

 

We found these shrimp in small patches of open sand between rocks in the intertidal zone.  Although the shrimp are so well camouflaged that we've probably walked by them many times without noticing them!

 

I can't help showing a few close-ups so you can appreciate how well they match the sand.  One of the anterior end (with two rounded pearly eyes), one of the tail, and a close-up of the pigment spots called chromatophores (there are also some actual sand grains on the shrimp):

 

 

 

 

 

 

 

P.S.  I showed a photo of Crangon handi from a more wave-exposed site back in June — see "Perfect match" on 23 June 2023.  Note that the larger color patches on that shrimp match the coarser grains on the outer coast.

 

P.P.S.  There are a few things about these shrimp that stray from the original description — e.g., we found them on finer-grained sand and their color patterning is finer.  However, we noticed a photo in Jensen's Crabs and Shrimps of the Pacific Coast (2014) that shows Crangon handi with similar patterning to the shrimps we photographed.  But if you have thoughts about this identification, let us know!  We're interested and open to looking further at any defining traits for this species.

 

Find the shrimp?

  

Can you find the shrimp?

More info tomorrow night!