Last night I mentioned butterflies zipping by, and that I wasn't sure if they were SatyrAnglewings (Polygonia satyrus) or California Tortoiseshells (Nymphalis californica). There were even more butterflies today, and I finally got a few photos.
The first photo was one for documentation, but I like it because the butterfly was perched on a seine net:
Then I managed to get a few morephotos — here's one from above:
Compared to Satyr Anglewings (see last night's post), note that California Tortoiseshells have fewer dark spots on the hind wings, pretty blue spots along the trailing edge, and relatively smoother wing margins (anglewing is an appropriate name for the other species).
Here's the view from below. I love the coppery tones and the bark-like appearance:
You can see how well camouflaged California Tortoiseshells are against background vegetation when their wings are closed:
So this is the first time I've seen California Tortoiseshells on Bodega Head. It was so much fun to see them flying in off the water (most were flying west to east), and to wonder where they were coming from and where they were going! This species is known to undertake long-distance movements, so it's not necessarily surprising to see large numbers of tortoiseshells flying by. However, in my experience here during the last 12 years, it's uncommon (rare?) to see this species, and large movements of this species, along the coast. (Large movements are more common in the mountains.)
I'd love to hear about other tortoiseshell sightings in this area, so let me know if you see them!
Several days ago, Peter was showing me some algae that he had collected on the tidal flats in Bodega Harbor. When he picked it up, a small nudibranch-like animal was left behind in the tray. I was intrigued because it didn't look familiar to me. When we looked at the animal under the scope, we realized that it wasn't a nudibranch, but a sacoglossan — a group that is sometimes known as "sap-sucking sea slugs." From the name, perhaps you can guess that sacoglossans eat algae.
Here's one of the first views we had. Note the small, black eyes and the large, rolled rhinophores above the eyes:
There are many projections called cerata on the back — cylindrical, greenish, with scattered gray flecks and white tips:
On the underside, you can see a smooth muscular foot with irregular black splotches (creating a marbled pattern):
Meet Aplysiopsis enteromorphae!
While we watched, the most striking thing about this species was its feeding behavior.
Aplysiopsis enteromorphae is known to feed on only a few species of seaweeds. (This individual was feeding on Chaetomorpha.) The feeding behavior was described originally by Gonor (1961). The slug grasps the algal filament with the front of its foot and a pair of oral lobes (see diagram below). It slices open an algal cell with a single row of teeth on its radula, sucks out the contents, and then repeats this process along the filament. After the filament passes by the mouth, it's easy to see the now-empty algal cells!
Modified from Gonor, J.J. 1961. Observations on the biology of Hermaeina smithi, a sacoglossan opisthobranch from the West Coast of North America. Veliger 4: 85-98.
This is exactly what we saw:
Here's an even closer view. Look for the solid green algal strand in front of the mouth (at the bottom of the photo), and the nearly-clear algal strand after it leaves the mouth and passes along the foot. The eaten portion of the strand is a little hard to see because it's almost transparent, but there are a few green cells left:
We were curious about whether you could see the slits in the algal cells. We couldn't with our eyes alone, so we put a strand under a compound microscope (200x magnification), and voilà! Below, the arrows are pointing to two of the slits:
Eric was able to capture a few seconds of feeding behavior on video. Watch carefully as the slug moves along the single strand of Chaetomorpha— grasping, slitting, and sucking out the contents.
Spiny Lobster (Panulirus interruptus) molt, washed up on Bodega Head, 19 September 2017
Although we had wondered if we'd ever find a Spiny Lobster in Bodega Bay, we were surprised to look down and see this on the beach tonight.
Spiny Lobster are a southern species — they are primarily found south of Point Conception, and they're most abundant off the central coast of Baja California, Mexico. During El Niño years, they may be observed north to Monterey. Since about 2011, molts have been discovered occasionally in San Francisco (Crissy Field) and Bolinas (Agate Beach).
There is a 2001 record for a post-larval stage Spiny Lobster in Bodega Harbor, but to our knowledge, this is the first record of an adult Spiny Lobster molt in Bodega Bay, and therefore the northernmost record for a Spiny Lobster molt on the West Coast!
Spiny Lobsters can reach a carapace length of ~44 mm in 2 years. The molt we found was missing the carapace, but we can still come up with an estimate — see photo with ruler below:
Here's some rough, but interesting guesswork. The carapace on this individual might have been ~50 mm long...which is a potential match for a 3-year old lobster...which is a potential match for a lobster that settled in northern California during the warm-water anomaly ("The Blob") in 2014. We have some research to do on these measurements, but it's interesting to think about when the lobsters might have arrived on our coast.
We'd be very interested in any other sightings of Spiny Lobster molts from Point Reyes north, so let us know if you spot any washed up on the beach (and please take a photo)!
P.S. I was curious about the scientific name. The specific epithet "interruptus" comes from the interrupted groove on each abdominal segment. Below, note the gap (white arrow) separating the grooves that run through the middle of each abdominal segment:
Not much time tonight, but here are a few more pictures of White-tailed Kites just before heading to a roost site for the night on 17 September 2017. (Click on the images for larger versions.)
A beautiful immature bird, with rusty coloration on the breast, white-edged feathers behind the "black shoulder", and gray at the back of the head. (The eyes are also darker than those of an adult.)
Below, the immature kite turns to watch another individual trying to land nearby. This is a good look at the underwing pattern (and the tail feathersbeing molted — note the different lengths of the feathers).
A kite soaring overhead with just a hint of the setting sun:
Just a few quick shots of the White-tailed Kites coming in to roost tonight (16 September 2017):
Since the kites fly in just before sunset, the light is quite dim. I don't have the right camera lens for these conditions, so most of my shots are blurry, but even so, I can't help sharing this one (below). I love that you can still see the coloration of the young bird on the right — the beautiful rust color on the breast and the grayish cap:
There were interesting conditions and behaviors tonight. It was one of those late summer nights that makes you want to linger outside, and the kites seemed to think so, too! They perched high on the trees overlooking the roost site, kept circling around high above, and they stayed out until it was almost too dark to see them.
I'm so thankful for the opportunity to spend time watching kites!
Last night Will mentioned he had seen some gorgeous toads...so how could we resist? After work, Eric and I took a short walk in Sugarloaf Ridge State Park. Sure enough, just after dusk, we started seeing toads along the path. Below are a few of my favorite pictures. These are Western Toads (Anaxyrus boreas, formerly Bufo boreas). They ranged in size from about ~2-4" (~5-10 cm) long, shown here from largest to smallest:
This was the first time we've seen Western Toads in Sonoma County. It was so nice to see them! Thanks, Will, for letting us know about the wonderful toads.
We were fortunate to see a few Blue Whales (Balaenoptera musculus) near Cordell Bank on 10 September 2017. [Click on the photos for larger versions.]
Here's another example of the very long back and the very small dorsal fin (relative to the size of the whale, that is). Compared with the first photo (above), note the slightly different shape of the fin, as these are different individuals:
Sometimesthe mottled patterning on the back was visible:
Below, on the right, look for the large "splashguard" surrounding the blowholes:
From a slightly different angle:
And one more, this time of the flukes, with the impressively thick caudal peduncle, or tail stock:
For more photos and information about Blue Whales, review the following posts:
During the pelagic trip on Sunday (10 September 2017), we had great looks at a group of Dall's Porpoises (Phocoenoides dalli) as they swam alongside the boat.
Dall's Porpoises are always fun to watch, but incredibly frustrating to photograph. They're so fast — with swimming speeds up to ~30 knots (!), they're one of the fastest of the small cetaceans — and when they surface, it's usually with a very dramatic splash (often called a "rooster tail"). Mostly I end up with photographs of not much animal and a lot of splash. Here's an example of a Dall's Porpoise surfacing:
Below, I've zoomed in so you can see different features. Dall's Porpoises are mostly black, so the bright white thoracic panel (coming up the side) stands out. Above that you can see the triangular dorsal fin with a bit of gray frosting at the tip. And note the small dark pectoral fin between the white panel and the head.
Just for fun, and because they create interesting patterns, here are some of my best Dall's Porpoise splashes of the day. [Click on the pictures to see the finer details.]
Interesting sky and weather tonight! Dark storm clouds moved in just before sunset, accompanied by strong, swirling breezes. The White-tailed Kites that have been roosting nearby responded by arriving at the roost site earlier than usual, soaring much higher than usual, and flying in to the roost site very fast at a very steep angle.
It looked like there were some rain showers up high:
And then some intriguing rainbows surrounded by a rosy blush appeared to the east:
Not too long after, the sun lit up the western clouds: