I had seen the sea lettuces (Ulva spp.) spawning in these high pools at Franklin Point before, and usually cursed the murkiness of the water. But today the water was dead calm, with the tide low enough that there were no waves to slosh into the pools. The result was a gorgeous marbled swirl in the water. The patterns were stunning.
What these photos show is the Ulva releasing either spores or gametes. Without microscopic examination it's impossible for me to know whether these tiny cells are spores or gametes. What I can say is that the spawn is released from the distal ends of the thallus, making the body of the alga look ragged.
The parts of the thallus that have already spawned are now clear. The tissue itself will soon disintegrate, leaving behind only the healthy green parts, which should be able to regrow.
All of these photos were taken in pools where the spawning itself had either completely or mostly stopped. Obviously when the tide comes back all of this yellow spooge will get mixed up. It's only when the water is perfectly still that these streams would form. It was hard stepping around the pools to take the photos, as the last thing I wanted to do was stomp my big booted foot into a pool and disrupt the beautiful patterns. Fortunately the sun angle was a little cooperative this morning, and I was able to find a pool where active spawning was happening.
What appears to be an act of destruction—the alga's brilliant green thallus being reduced to yellow streaks that drift away with the tide—is really an act of procreation. This is terminal reproduction, literally the last thing an organism does before it dies. Salmon do this, as do annual plants. The sheer amount of algal spawn in these tidepools is astounding. Imagine the number of 2-micron cells needed to color the water to this degree. But if reproducing is the last thing you're going to do in your life, you might as well go all in on your way out, right?
A utility pole across the street and one house down has, for years, been an object of interest for a variety of birds. The hairy and downy woodpeckers drum on it in the spring, and various songbirds hang out and rest on the top. About a month ago now I saw a raptor up there, eating something. It was a female merlin (Falco columbarius). According to Cornell's All About Birds, merlins are in our area during the nonbreeding season, but I've never been certain about having seen one.
On the morning of Saturday 13 March I went outside to look around, and saw a bird on the pole. It appeared to be either eating or cleaning its beak. I ran inside to grab the camera, which fortunately had my longest lens and the 1.4x teleconverter attached, and snapped off a bunch of shots. The sun was rising, but I was able to get some decent photos of the bird even though from the best vantage point it was backlit.
Clearly, he's eating something:
But what is it eating? Rodent bits?
No, look at that foot. It's a bird!
Yep. Definitely a bird.
And here he is, taking a break between courses:
Merlins are members of the falcon family. Smaller birds make up the majority of a merlin's prey, but they also eat large insects such as grasshoppers. As with peregrine falcons, merlin populations were severely reduced in the years when DDT was widely used to keep insect populations down, but they have since recovered. Truly, the recovery of birds of prey after DDT was banned is one of the great successes of conservation biology.
There were feathers in the street below the pole. I assume they are from the merlin's prey, as when I looked at the top of the pole through binoculars I could see the same sort of feathers up there. I compared the feathers with photos on a few ID sites, but it's no easy identifying feathers without any additional context. Someone suggested that they might be from a male house finch. We have lots of those around all the time, so that's probably the best guess possible.
So there you have it: Saturday brunch with songbird on the menu!
For several weeks now I've been raising another batch of bat star (Patiria miniata) larvae, from a fortuitous spawning that occurred in early January. Since this is rather old hat by now I'm not diligently taking photos or drawing the larvae as often as I would have years ago when this kind of undertaking was new to me. But I still change the water twice a week and look at them on Fridays, and I still have the set-up that attaches my old phone to the microscope so I can take pictures of them.
Last Friday it occurred to me that: (A) my gizmo holds the camera steady over the microscope, so I can take pictures at multiple focal planes within objects under the scope; and (B) I have software that will stitch those many snapshots into a single image. Neat!
So I made this:
This larval stage is called a bipinnaria or a brachiolaria. From top (anterior end) to bottom (posterior end) the larva is about 1 mm long. It swims with the anterior end in front. In some sea stars the bipinnaria grows long arms, at which point we call it a brachiolaria ('brachio' = 'arm' in Greek). Bat stars don't grow long arms, so the distinction between bipinnaria and brachiolaria is much fuzzier.
I took 11 photos of this larva, each one focused on a different horizontal plane, and did a focus merge in my photo processing software. Crossed my fingers as the software did its magic, and then peeked at the result. It worked! When looking through the microscope I have to focus up and down through the body to get an idea of its three-dimensional structure. But if the animal holds still long enough, I can do the focus merge thing and get images like this one.
And that slight halo that you see around the exterior surfaces of the larva? That is not an artifact of the photo taking or processing. That halo is due to the cilia that cover the body. There is a ciliated band, which you can see as the dark gold ribbon that snakes along the lobes of the body, and the other body surfaces are ciliated as well. The ciliated band is what the larva uses to swim through the water. Each photo freezes the ciliary action at the moment it was shot, but stitching several photos together causes the cilia to blur into that pale halo.
Another guest blog entry by my husband, Alex Johnson
22 September 2020 Lake McDonald, Glacier National Park, Montana
Thirty four years ago I worked as a seasonal employee in Glacier National Park. My first job - and my most favorite - was Information Desk Clerk. I found I loved sharing my enthusiasm for the park with all the other visitors.
However, as with any job, it wasn’t always rosy. One of my tasks was to book trips for the famous open-top Red Bus tours. Of course being in the mountains, the weather wasn’t always cooperative. (We had snow in the park on the 4th of July both seasons I worked there!) On those days I would often hear from disappointed passengers: “We couldn’t see anything”, or “It was cold and rainy the whole day”, they’d complain.
I never fully understood this. Of course I know that some of the grand vistas can be obscured and the postcard-blue skies are hidden at these times. But in my experience, some of the most magical and transcendent moments happen during mountain storms, and particularly as those storms clear. The clouds dance amongst the peaks, the waterfalls come alive, the colors become vivid, and the wind sings. And the light can be incredible. Yes, it can be cold and sometimes uncomfortable, but when the storms clear, there’s no describing it.
Today I was back in Glacier again, this time alone. I’ve been back only twice since my employee days, and that hasn’t been nearly enough. It was one of those stormy days, with a steady rain and slate grey skies. It wasn’t too cold (for September), there was very little wind, and the clouds were doing their dances through the peaks. So, on the spur of the moment, I decided to take a hike on the Highline Trail out to Haystack Pass and back, a walk of about 8 miles. The Highline is a spectacular trail, starting at Logan Pass and traversing for miles along a gigantic glacial arête know as the Garden Wall all the way to Canada.
The walk out was beautiful, if a bit wet. I took my time, looking for sheep and mountain goats, and pausing to take lots of pictures. At Haystack Pass, I stopped to have a bite to eat. There’s not really any shelter there, so by the time I was finished I was starting to get cold. My fingers were suffering most, and were pretty well numb by the time I got going again. However, with a vigorous start to the hike back and keeping my hands in my pockets for a while, I gradually warmed up.
As I went along, the rain started to intensify and a chilly wind began to blow down from the Garden Wall above me. I picked up my pace, both to stay warm and to hasten my return. Then, after some 20 minutes, the clouds started to loose their grey, the wind began to die down, and the sun started to peek through the clouds above Mt. Oberlin to the west.
As the sun started to shine through the trees in front of me, an image of my best friend from those Glacier days, Chis Wall, came into my mind.
Chris was the Front Desk manager at East Glacier Lodge where I worked, and was technically my boss. However, he an I hit it off and did lots of hiking and climbing together. After Glacier, Chris went on to work at Sequoia National Park with his girlfriend Ellen (whom he also met in Glacier). I visited them there several times. One summer they managed the Bearpaw Meadow High Sierra Camp, and I hiked in the 11 miles to spend a week with them. I kept in contact with Chris and Ellen for number of years. I even recall traveling to Tuscon for their wedding. Later, they moved back to Massachusetts where Chis was from, and we fell out of touch.
Some time ago I ran across Chris’ obituary online. He had died too young of brain cancer, I believe.
When the sun came out today, I remembered another time like this, with Chris singing the Beatles song, Here Comes the Sun.
“Here comes the sun, doot-n-do-do. Here comes the sun….”
I could picture him, with his infectious grin, his happy voice, the bandana he always wore on his head, as well as his out-of-tune singing. I could even see the four tube socks he wore with his hiking boots, two on each foot, none of which matched any other. (This was a particular point of pride with him.)
The rains stopped. The air warmed. The clouds danced and swirled. The waterfalls came alive. The colors were vivid. And the light was incredible.
It was a perfect day for a walk in the mountains.
Thanks for meeting me up there again today, old friend.
We have all heard about hummingbirds and their ability to hover and fly backwards. These tiny feathered jewels are a delight to observe. They are birds of the New World, and I feel sorry for people living in parts of the world that don't have hummingbirds. Where I live, on the coast of Northern California, the resident hummers are Anna's hummingbirds (Calypte anna). We get the occasional Rufous and Allen's hummers (Selasphorus rufus and S. sasin, respectively) passing through on their migrations, but the Anna's are here year-round. We have front-row seats to watch their mating displays, and I know they must be nesting nearby even though I've never managed to locate a nest.
The other day, while sheltering in place at home, I went outside to photograph birds. The Anna's hummers were putting on quite a show. The males have been displaying since February, flying straight up-up-up and then plunging into a J-shaped dive near an observant female. At the bottom of the dive the male uses his tail feathers to create a sharp and very loud chirp. When this occurs about a meter from your head, it sounds like a pistol shot. Trust me on this.
Anyhow, that day I was lucky and captured some shots of a male Anna's hummingbird hovering in place. These aren't National Geographic quality photos, but then again I'm not a National Geographic-caliber photographer. For anyone who is interested in such details, here are the EXIF data:
300mm f/4 lens
1/2500 sec at f/4
At a shutter speed of 1/2500 sec, you can freeze even the movement of a hummingbird's wings. You can see very clearly that although the bird's wings are moving, his head remains perfectly skill and his position doesn't change at all.
A hovering hummingbird moves its wings in a figure-8, similar to the sculling motion of a skilled rower. If you use your imagination a bit you can see the rotation of the wings in this set of photos.
Given the mandate to shelter in place at home, I don't know how many of the upcoming morning low tides I'll be able to explore. On the one hand, I'd be by myself, not risking exposing anyone to any germs I might be carrying. On the other hand, staying home means, well, staying home. The tidepools are calling to me, but this year I might not be allowed to accept the invitation. All for the greater good, right?
We Californians are all under a state-wide mandate to stay at home, to minimize the spread of COVID-19 this spring. School hasn't been cancelled, but all classes have converted to distance learning. I had four days to figure out how to deal with that. Fortunately we are in spring break this week, which gives us all a little bit of a breather. I'm going to use the time to catch up on grading and plan for the second half of the semester.
The marine lab is also closed for business. Only essential personnel are allowed to be there. The term 'essential personnel' includes people whose responsibilities are animal husbandry. Since animals will die if I'm not there to feed them, I have met that criterion for essentiality. That's not a word, but you know what I mean. With so many fewer than usual people at the marine lab, there's a lot more wildlife activity. A few days ago I saw a long-tailed weasel (Mustela frenata) chase down and capture a young brush rabbit. I just barely had time to catch a quick shot with my phone.
The most noticeable thing, though, is the increased birdsong. The sparrows, finches, red-winged blackbirds, mallards, doves, towhees, and hawks are all making a lot of noise. The barn swallows (Hirundo rustica) returned to the lab on the 21st, right on time! Maybe this year they'll have a more successful nesting season than they did last year.
Yesterday I witnessed something I'd never seen before: a territorial dispute between a black phoebe (Sayornis nigricans) and a barn swallow. The fact that I had never seen it before in no way implies that it happens only rarely; maybe I've just never paid that much attention to these things before, or they've never happened while I've been around to watch.
Here's the story, in a series of snapshots.
Prologue. The barn swallow (H. rustica) is perched on one of the outdoor light fixtures. The phoebe (S. nigricans) swoops up from below.
The swallow takes to the air, only to be divebombed by the phoebe.
The swallow retreats. . .
. . . and the phoebe perches, triumphant, on the rain gutter.
The entire altercation lasted maybe as long as four seconds. I didn't see where the swallow flew. The phoebe remained on the rain gutter for about a minute or so, then took off over the meadow. Perhaps it has a nest somewhere nearby and was defending it. Both species build mud nests on cliffs and buildings, so these birds could be competing for nest sites. Or maybe phoebes just don't like swallows. Either way, this was the sort of interaction that I don't notice when there is a lot more human activity at the marine lab. Nature has a way of re-asserting herself when humans are removed from the scene for even a short period of time.
Of course, sea anemones don't have faces. They do have mouths, though, and since a mouth is usually part of a face, you can sort of imagine what I'm getting at. The sunburst anemone, Anthopleura sola, is one of my favorite intertidal animals to photograph. Of the four species of Anthopleura that we have on our coast, A. sola is the most variable, which is why it keeps catching my eye.
This afternoon I met the members of the Cabrillo College Natural History Club for the low tide at Natural Bridges. Here are some of the A. sola anemones we saw.
Such an amazingly photogenic animal, isn't it?
This past Fall semester the NHC went tidepooling at Pigeon Point. Today we were at Natural Bridges, and later in the spring we are going to Asilomar. I didn't intend it, but this school year the club is getting a look at three very different intertidal sites.
It's no secret that I love pelicans. I love watching them soar low over the waves, where they are truly in their element. I love watching them plunge from the air into the water and then bob right back to the surface, because unlike their cormorant relatives, pelicans can't fly underwater. And I love watching them plunk around on land, where they are dumpy and awkward but still somehow elegant.
The other day I ventured out between storms to photograph birds. As per usual I ended up down at Natural Bridges, where pelicans were hanging out on the last remaining rock arch. They were well within the reach of my long lens, so I took a lot of photos.
The best photos I got were of a subadult pelican coming in for a landing.
Landing gear down!
Decreasing air speed:
And. . . touchdown!
A job well done!
The youngster managed a safe landing without knocking one of its compadres into the water. That isn't always the case--those wings can do a lot of damage. But the three adult birds on the left hardly seemed to notice, which means the youngster has learned how to stick the landing without disturbing everyone else in the vicinity. I'm sure that's a lot easier said than done!
Autumn is migration season in California. We all know that, in the northern hemisphere, birds fly south for the winter and return north for the summer. And indeed, this is a very good time to go bird watching along the Pacific Flyway, as migrating birds stop to rest and feed at places such as Elkhorn Slough. Here in Santa Cruz, autumn is punctuated by the return of monarch butterflies (Danaus plexippus), roosting in eucalyptus trees at Natural Bridges State Beach and Lighthouse Field.
Since 1997 the Xerces Society for Invertebrate Conservation has been tracking monarch sightings on their migrations between the western U.S. and Mexico. They conduct a volunteer butterfly count every Thanksgiving. More recently, community science data sources such as iNaturalist provide much of the information.
This morning, before it got warm, I went to Natural Bridges to see how the monarchs were doing. I wanted to photograph clumps of butterflies dripping from tree branches. It seemed, however, that there aren't as many butterflies as I remember from previous years. The clusters were not nearly as large or as dense as they should be. And the data shown in the figure below do demonstrate a precipitous decline in monarch since 2017. We're still a couple of weeks away from this year's Thanksgiving count, and there is still a chance that the butterflies might arrive in larger numbers.
Trained observers know how to estimate the number of butterflies in a cluster like this. The numbers of butterflies at various roosting sites are aggregated to assess overall population sizes.
This morning I did see one butterfly that had a tagged wing. It was wearing a green Avery round sticker, with some writing in what looks like black Sharpie. The color of the sticker was very close to the green of the surrounding foliage, so I wasn't even able to see the sticker until I downloaded the pictures from the camera.
At first I thought the tag resulted from an official scientific project or undertaking, but it turns out that anyone can tag a monarch. The tags are used to track migration of the butterflies. There doesn't seem to be a central depository of tags and their origins, so knowing the color of the tag doesn't tell me where this particular butterfly came from.
Once the sun hits the butterflies and they begin to warm up, the clusters start breaking apart. Butterflies open and close their wings, exposing the darker dorsal surfaces to the sun and warming up their flight muscles. Sometimes they dislodge one another.
On a cool morning like this, many of the butterflies that fell out of the clump couldn't fly yet, and landed on the ground. The boardwalk is perhaps not the safest place for a butterfly to wind up, but at least in a monarch sanctuary such as Natural Bridges the visitors are knowledgeable and look out for the butterflies' safety.
As I wrote before, the butterflies we see at Natural Bridges this year were not born here. This means that their survival to this point has depended on healthy conditions in the Pacific Northwest and the western slopes of the Rocky Mountains, where they lived as caterpillars and emerged from their chrysalises. This also means that planting milkweed for monarch caterpillars in California won't help the butterflies that we see here, although it would help butterflies that are destined to overwinter elsewhere. What will help local butterflies--monarchs and otherwise, and all nectar-feeding insects, in fact--is planting California native plants, to provide them with the nutrition they have evolved to survive on.