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When low tides occur at or before dawn, a marine biologist working the intertidal is hungry for lunch at the time that most people are getting up for breakfast. And there's nothing like spending a few morning hours in the intertidal to work up an appetite. At least that's how it is for me. Afternoon low tides don't seem to have the same effect on me, for reasons I can't explain. A hearty breakfast after a good low tide is a fantastic way to start the day.

Sea anemones are members of the Anthozoa (Gk: 'antho' = 'flower' and 'zoa' = 'animal'). These 'flower animals' are the largest cnidarian polyps and are found throughout the world's oceans. They are benthic and sedentary but technically not sessile, as they can and do walk around, and some can even detach entirely and swim away from predators. The anthozoans lack the sexual medusa stage of the typical cnidarian life cycle, so the polyps eventually grow up and have sex. In addition to the sea anemones, the Anthozoa also includes the corals, sea pens, and gorgonians.

With their radial symmetry and rings of petal-like tentacles, the sea anemones do indeed resemble flowers. You've seen many of my anemone photos already. Here's one more to drive home the message.

Anthopleura artemisia at Pistachio Beach
27 January 2017
© Allison J. Gong

Sea anemones are cnidarians, and cnidarians are carnivores. Most of the time  anemones in the genus Anthopleura feed on tiny critters that blunder into their stinging tentacles, although the occasional specimen will luck into a much more substantial meal. I've watched hermit crabs crawl right across the tentacles of a large anemone (Anthopleura xanthogrammica), and while the anemones did react by retracting the tentacles, the crabs easily escaped their grasp.

Of course, not all potential prey items are so fortunate. Sometimes even big crabs get captured and eaten, like this poor kelp crab (Pugettia producta):

Kelp crab (Pugettia producta) being eaten by an anemone (Anthopleura sp.) at Davenport Landing
8 March 2017
© Allison J. Gong

There's no way to know exactly how this situation came to be. Was the crab already injured or weakened when the anemone grabbed it? Or was the anemone able to attack and subdue a healthy crab? I've always assumed that the exoskeleton of a crab this size would be too thick for the rather wimpy nematocysts of an Anthopleura anemone to penetrate, but maybe I'm wrong. A newly molted crab would be vulnerable, of course; however, they tend to stay hidden until the new exoskeleton has hardened, and the crab in the above photo doesn't appear to have molted recently.

Even big, aggressive crabs can fall prey to the flower animals in the tidepools. I'd really like to have been there to watch how this anemone captured a rock crab!

Giant green anemone (Anthopleura xanthogrammica) eating a rock crab, possibly (Romaleon antennarium) at Natural Bridges
17 June 2018
© Allison J. Gong

And crabs aren't the only large animals to be eaten by sea anemones. Surprisingly, mussels often either fall or get washed into anemones, which can close around them. Once a mussel has been engulfed by an anemone, the two play a waiting game. Here's what I imagine goes on inside the mussel: The bivalve clamps its shells shut, hoping to be spit back out eventually; meanwhile, the anemone begins trying to digest the mussel from the outside; sooner or later the mussel will have to open its shells in order to breathe, and at that point the anemone's digestive juices seep inside and do their work on the mussel's soft tissues. When the digestive process is finished, the anemone spits out the perfectly cleaned mussel shells.

Giant green anemone (Anthopleura xanthogrammica) digesting a clump of mussels (Mytilus californianus) at Natural Bridges
17 June 2018
© Allison J. Gong

In the photo above, the anemone is working on a clump of several mussels. I can't see that any of these mussels have been compromised, but the pale orange stringy stuff looks like mussel innards and slime. It could be that several mussels are still engulfed within the anemone. There is always a chance that an anemone will give up on a mussel that remains tenaciously closed, and spit it out covered with slime but otherwise unharmed. I assume that hungry anemones are less likely to give up their meals than ones that have recently fed.

So how, exactly, does an anemone eat a mussel, or a crab? The answer lies within the anemone's body. Technically, the gut of an animal is outside its body, right? Don't believe me? Let's think it through. An animal with a one-way gut can be modeled as a tube within a tube, and by that reasoning the surface of a gut is contiguous with the outer surface of the body. Our gut is elaborated by pouches and sacs of various sizes and functions, but is essentially a long, convoluted tube with a mouth on one end and an anus on the other. Sea anemones, as all cnidarians, have a two-way gut called a coelenteron or gastrovascular cavity (GVC), with a single opening serving as both mouth and anus. Anemones, being the largest cnidarian polyps, have the most anatomically complex gut systems in the phylum.

Imagine a straight-sided vase with a drawstring top. The volume of the vase that you'd fill with water and flowers represents the volume of the anemone's gut. Anemones can close off the opening to their digestive system by tightening sphincter muscles that surround the mouth; these muscles are analogous to the drawstring closure of our hypothetical vase. Now imagine that the inner wall of the vase is elaborated into sheets of curtain-like tissue that extend towards the center of the cavity. These sheets of tissue are called mesenteries. They are loaded with various types of cnidocytes that immobilize prey and begin the process of digestion. The mesenteries greatly increase the surface area of tissue that can be used for digestion. The mesenteries are also flexible and can wrap around ingested prey to speed things up.

This anemone (below) that was eating both a mussel and a piece of kelp:

Sunburst anemone (Anthopleura sola) having brunch at Davenport Landing
4 May 2018
© Allison J. Gong

Those frilly ruffles are the mesenteries. You can see how greatly they'd increase the surface area of the gut for digestion. They are also very soft, almost flimsy. Here's a close-up shot:

Gastric mesenteries of the sea anemone Anthopleura sola at Davenport Landing
4 May 2018
© Allison J. Gong

Maybe I'm especially suggestible, but seeing these animals working on their own meals makes me hungry, too. After crawling around the tidepools for a few hours I'm always ready for a second breakfast or brunch of my own.

Bon appétit!

Monterey Bay is shaped like a backwards letter 'C', with Santa Cruz on the north end and the Monterey Peninsula on the south end. The top of the 'C' is comparatively smooth, while the bottom is punctuated by the Monterey Peninsula, which juts north from the city of Monterey. The most striking geologic feature is the Monterey Submarine Canyon, but of course you can't see that from land. It is crazy to realize that the canyon starts right off the jetty at Moss Landing. It is this proximity to deep water that makes the Monterey Bay Aquarium Research Institute (MBARI) so ideally situated.

Monterey Bay, California
© Google Maps

Separated by 40.2 km (= approximately 25 statute miles) as measured harbor to harbor, Santa Cruz and Monterey represent both the same and slightly different marine habitats. On a large scale they are both part of the California Current system, strongly affected and biologically defined by seasonal upwelling in the spring and summer months. On a finer scale they differ in a few ways, primarily geologic. The rock on the Santa Cruz end of the bay is a soft sand- or mudstone, and at sites like Natural Bridges can be easily eroded; you can scratch it with your thumbnail, and falling on it might give you a bruise but probably won't beat you up more than that. The rock of the Monterey Peninsula is much less forgiving: granite with large quartz crystals. Falling on that stuff can leave you with bruises and a bad case of rock rash; I usually end up bleeding from at least one laceration when I'm in the intertidal there.

Limpet on granite on the Monterey Peninsula
16 June 2018
© Allison J. Gong
Barnacles on mudstone in Santa Cruz
17 June 2018
© Allison J. Gong

The difference in rock type between the north and south ends of Monterey Bay also manifests in the tidepools themselves. The soft mud stone of the Santa Cruz erodes into small particles, which form nice soft sandy beaches. Small particles also remain suspended in water more so than larger ones, which affects water clarity. Larger and heavier particles, on the other hand, sink out of the water, so that the water column itself tends to be less murky. Clear water has some marked advantages over murky water. For example, light transmission is directly proportional to water clarity. Thus, all other factors being equal, photosynthetic organisms such as algae have access to more light, in waters above large-grained sand than those above finer sediments.

That being said, it is not always the case that clearer water is better. Remember Phragmatopoma californica, one of the worms I wrote about recently? They build tubes out of sand grains. However, it turns out that they are particular about the sand grains they use. If you were to examine a Phragmatopoma tube under a dissecting scope you'd see that all of the sand grains are the same size. Just how they select and sort the sand grains isn't understood, but somehow they manage to choose the particles they want and cement them together underwater. Phragmatopoma is one of the most conspicuous animals at Natural Bridges on the north side of Monterey Bay, forming large mounds of hundreds of individuals, yet very few live on the Monterey Peninsula. There are likely several reasons for this, but part of the explanation is that the sand grains are too big to be used in the worms' tubes.

I live in Santa Cruz, on the north end of the bay, and most of my intertidal excursions these days are to locations in Santa Cruz and north along the coast. I haven't spent nearly as much time as I'd like to in the tidepools on the Monterey Peninsula and locations further south. It's tough getting to a site an hour away, when the low tide is at dawn. And with my post-concussion syndrome I don't yet feel comfortable driving myself that far away and back. Fortunately for me, I am currently mentoring a student working on an independent study project, and she was willing to drive down to Asilomar last weekend. So I tagged along with her.

Monterey Peninsula
© Google Maps

Asilomar State Reserve is one of California's no-take marine protected areas (MPAs), where people can look and take pictures but are not allowed to remove anything, dead or alive. It is a glorious site. The water is clear and blue, and the biota is both similar to and different from that on the north side of the bay. I want to highlight some of the organisms that I see there, that are less common here on the north side.

Black abalone (Haliotis cracherodii) at Asilomar State Beach
16 June 2018
© Allison J. Gong

Abalone (Haliotis sp.) are not unheard of here. In fact, there is a black ab (H. cracherodii) at Natural Bridges that I've been keeping an eye on since 2015, tucked into a crevice and generally not visible except on a minus tide. And further north at Pigeon Point I have seen red abalone (H. rufescens), both living and empty shells. But I've never seen as many black abs as I saw at Asilomar. Standing in a depression about as big as my kitchen table, well above the water level, I easily counted at least 20 black abs. Some of them were as big as my hand. How many can you see in the photo above?

Black abalone (Haliotis cracherodii) at Asilomar State Beach
16 June 2018
© Allison J. Gong

Abalone are large herbivorous snails. They feed on macroalgae, both reds and browns. If they venture from the safety of their nooks and crannies they can chase (at a snail's pace) down algae, but then they are vulnerable to predators such as cabezons and sea otters. Abs that live in crevices, like these, have to rely on drift algae to come to them; they don't have the luxury of choosing what to eat. It's the age-old compromise between safety and food, one of the driving forces in foraging behavior.

While we have four species of anemones in the genus Anthopleura at the Santa Cruz end of the bay, as well as other anemones such as Epiactis, we don't have any in the genus Urticina--not intertidally, at least. I have seen Urticina anemones at Carmel, and last weekend saw what I think was U. coriacea. It was in a pool, and partially obscured by sand and its own pharynx.

The anemone Urticina coriacea at Asilomar State Beach
16 June 2018
© Allison J. Gong

It's own pharynx, you ask? Yes! Anemones are cnidarians, and as such have a two-way gut. This means that food is ingested and wastes are expelled via a single opening, which for politeness' sake we call a mouth even though it also functions as an anus. Sometimes, when an anemone is expelling wastes, it also turns out the top part of its pharynx. This is a temporary condition, and the pharynx will be returned to normal soon. The anemone in the picture above appears to be in the process of spitting out something fairly large and undigestible.

Here's another example of an anemone eating a big meal, this time of mussels.

Giant green anemone (Anthopleura xanthogrammica) snacking on a clump of mussels (Mytilus californianus) at Natural Bridges
17 June 2018
© Allison J. Gong

What do you think this thing (below) is?

Pista elongata at Asilomar State Beach
16 June 2018
© Allison J. Gong

I had at first misidentified these as something else, but have since been told that they are the tubes of another of those strange terebellid polychaete worms. This one is Pista elongata. As with many terebellids, P. elongata lives in a tube, the opening end of which is elaborated into a sort of basket. They reportedly range from British Columbia to San Diego. I think I've seen them at Carmel Point, but not at Point Piños, which I've visited more often. And I'm positive I've never seen it at Natural Bridges.

At Asilomar I saw some large clusters of P. elongata in the low intertidal. They are not clonal, to my knowledge, so these aggregations would form by gregarious settlement of competent larvae when they return to shore.

Cluster of Pista elongata at Asilomar State Beach
16 June 2018
© Allison J. Gong

One solitary ascidian that I saw at Asilomar is Clavelina huntsmani, the appropriately called lightbulb tunicate:

The "lightbulb tunicate" Clavelina huntsmani at Asilomar State Beach
16 June 2017
© Allison J. Gong

For people too young to remember what an incandescent light bulb looks like, they were made of clear or frosted glass. Inside the glass bulb were tungsten filaments, through which electricity flowed; the filaments heated up enough to emit light. In Clavelina, the two pink structures running down the length of each zooid resemble the filaments of an incandescent light bulb, but are in fact parts of the pharyngeal basket, the structure used for filter feeding.

We have neither Pista nor Clavelina in Santa Cruz--at least, I've never seen them. They remind me that although Santa Cruz and Monterey are part of the same ecosystem, they do not represent the same microhabitat. I'm pretty familiar with the intertidal floral and fauna in Santa Cruz, but I absolutely love exploring the intertidal along the Monterey Peninsula. There's something exciting about spending time a place I don't know as well as the back of my hand. I hope that as my brain continues to heal I'll eventually regain the stamina to travel so far for a low tide.

1

Today is the first day of the week of low tides dedicated to Snapshot Cal Coast, a statewide citizen science project headed in my area by the California Academy of Sciences. This week groups and individuals will be making photographing the organisms they see in the ocean or along the coast, and uploading observations to iNaturalist. Participants will include both scientists and non-scientists, making the week-long event one of the biggest citizen science projects that I regularly take part in. Next Monday I'll be taking a group of Seymour Center volunteers and staff up to Davenport to conduct a Bioblitz. The other days I'll be out on my own, or with 1 or 2 people.

This morning the low tide was very early (-1.3 feet at 05:09), so I stayed close to home and went to Natural Bridges. The tide was low but the swell was big and I wasn't able to get down to the low spots I could normally reach with this kind of tide. However, this meant that I could spend more time in the low-mid-intertidal, where there is a lot of biodiversity to document.

Today I want to write about polychaete worms. These are the segmented marine worms in the Phylum Annelida, which also includes earthworms and leeches.

Worm #1: Phragmatopoma californica

One of the most conspicuous inhabitants of this zone is the tube-dwelling polychaete worm, Phragmatopoma californica. This worm has a couple of common names: honeycomb worm, which refers to the mounds of tubes they build; and sandcastle worm, for the fact that the tubes are built of cemented sand grains. In effect, these worms are tiny masons!

Mound of Phragmatopoma californica tubes at Natural Bridges
26 May 2017
© Allison J. Gong

Each of the tubes is inhabited by a single worm. Mounds form because competent Phragmatopoma larvae, looking for a place to settle out and live permanently, are attracted to the tubes of existing adults. This phenomenon is called gregarious settlement. Once settled and metamorphosed, juvenile worms build their tubes by selecting sand grains and cementing them together around a lining of chitin-like material. How they do it, underwater, nobody knows. And these tubes are tough! The worm inside is skinny, and a humongous one would be all of 4 cm long, but it takes a lot of force to pry apart those sand grains. The openings to the tubes are 5-10 mm in diameter. Each worm can close off its tube with a circular-ish disc of stiff, fused chaetae called an operculum; this protects the worm from both predators and desiccation.

When the tide is out the worms withdraw into their tubes and clap the operculum down. They wait for the water to return. Phragmatopoma is a filter feeder; like most of the tube-dwelling polychaetes these worms use a crown of ciliated tentacles to create water currents that draw food particles to the mouth. When the tide is in the worms pull down the operculum and extend their feeding tentacles into the water. In the field, this is the most you can see of the worm's body.

Feeding tentacles of Phragmatopoma californica at Natural Bridges
13 June 2018
© Allison J. Gong

Worm #2: Serpula columbiana

Many polychaetes live in tubes, and tubes can be made of a variety of materials. Phragmatopoma californica builds tubes out of sand grains. Another worm that I saw today, Serpula columbiana, builds tubes out of CaCO3 precipitated from seawater. Like other animals that build calcareous skeletons, S. columbiana may in the future have difficulty precipitating CaCO3 in an increasingly acidic ocean. Tubes of Serpula worms are white when new and soon become fouled with algal growth, and tend to wander over the substrate. The best photo I could take this morning is a little blurry but you can see the general morphology of the tubes.

Calcareous tubes of Serpula columbiana at Natural Bridges
13 June 2018
© Allison J. Gong

These worms are incredibly shy, and react to any perceived threat by pulling into their tubes. Their tentacles have tiny eyespots that can detect changes in light, so passing a hand over them can cause them to withdraw. Fortunately I was able to sneak up on one lazy worm in a pool, and grab a shot of its 'head' region. Worms that live in tubes are poorly cephalized, with none of the structures that we generally associate with a head. Serpula columbiana's 'head' looks like this:

Anterior end of Serpula columbiana at Natural Bridges
13 June 2018
© Allison J. Gong

The tentacles of S. columbiana are morphologically complex compared to those of Phragmatopoma. Serpula's tentacles are pinnate, or feather-shaped, and in cross-section look like a V. Cilia on the side branches of the tentacle create the feeding current, and food particles are transported by other cilia down the trough of the V to the mouth.

See that long, trumpet-shaped structure? That's the worm's operculum!

Worm #3: Unidentified cirratulid

Unlike Serpula and Phragmatopoma, worms of the Family Cirratulidae don't live in tubes. Instead, they live with most of the body hidden in crevices, and extend tentacles to feed.

Feeding tentacles of an unidentified cirratulid polychaete worm at Natural Bridges
13 June 2018
© Allison J. Gong

As you can imagine, it is extremely difficult to identify a worm when all you can see of it are its tentacles; with the rest of the body hidden in a crevice, there are no visible characteristics to use to distinguish species. Cirratulids use their tentacles to feed, but in a way that is entirely unlike how Phragmatopoma and Serpula use theirs. Instead of feeding on particles suspended in the water, cirratulids are deposit feeders. They sweep their tentacles across the surface and collect organic deposits. Sticky mucus on the tentacles picks up organic matter, and cilia on the tentacles sweep the organic matter to the worm's mouth.

Don't believe me? Watch this!

It doesn't matter if the surrounding substrate is sand or rock. The cirratulid's sticky tentacles are very effective at gathering organic muck.

Worm #4: Flabesymbios commensalis

This worm remains an enigma. There doesn't seem to be much known about its biology. I have seen them twice, both times on the body of purple urchins (Strongylocentrotus purpuratus), and although the genus name has changed twice since the first time, I'm pretty sure it's the same worm. As the species epithet commensalis implies, this worm is a commensal on sea urchins. This means that it neither harms nor benefits its echinoderm host. Similar to the worm I've seen on bat stars, F. commensalis presumably cruises over the urchin's body and feeds on detritus or scraps of kelp that the urchin grabs.

When I took the photo in a tide pool this morning I didn't see the worm. It wasn't until I downloaded the pictures from the camera onto my computer that I saw it. See how well it blends in with the urchin's color?

Purple urchin (Strongylocentrotus purpuratus) at Natural Bridges
13 June 2018
© Allison J. Gong

Here's a tighter crop of that photo:

Flabesymbios commensalis on aboral surface of a purple urchin (Strongylocentrotus purpuratus) at Natural Bridges
13 June 2018
© Allison J. Gong

For many polychaete worms, another animal's body seems to be the ideal habitat. And for some reason, echinoderms are likely hosts for such commensal worms. I've written about the bat star worms, here is the urchin worm, and there's also a scale worm that I've seen crawling around on the body of a sea cucumber. What is it about echinoderms that makes them habitat for worms? Or is this type of commensalism also common, but less observed, between polychaetes and other non-echinoderm invertebrates? I don't know the answer to either of those questions, but am very intrigued.

1

This morning, after months of invitations that I could not accept due to teaching commitments, I was finally able to join a group of folks at the Younger Lagoon Reserve (YLR) for their weekly bird banding activities. During the summer months they start early, trying to catch birds in the few hours after dawn. I didn't get out there until almost 07:00, and they had been "fishing" for about 45 minutes already. They were finishing up the process with a Wilson's warbler and went out to release the bird as I came up.

Bird banders waiting for some action at Younger Lagoon Reserve
8 June 2018
© Allison J. Gong

Bird banding activities are overseen by a person who holds state and federal permits to work with birds. The permit holder for the Younger Lagoon Reserve and the Fort Ord Natural Reserve is Breck Tyler. Either he or his partner, Martha, must be on site whenever birds are being banded. The other regular participants are YLR staff members Vaughan Williams (Restoration Field Manager), Kyla Roessler (Assistant Restoration Steward), and various UCSC undergrads who are interns, volunteers, or students visiting with classes. Back in March I brought my Ecology students to YLR to observe bird banding and work on vegetation restoration in the Reserve's terrace lands; on that day we did help with planting, but got skunked on birds.

When I arrived this morning it was sunny and cool. Vaughan told me that the best weather for bird banding is one of the overcast, foggy mornings that we often get in the summer. When it's sunny, like it was today, the birds can see and avoid the nets.

Mist net at Younger Lagoon Reserve
8 June 201
© Allison J. Gong
Bird banding equipment
8 June 2018
© Allison J. Gong

The mist nets are made of an extremely fine nylon mesh. They are very loose and flexible and don't hurt the birds. A bird flies into the net and gets tangled in it. If the bird is heavy enough, it and the mesh it is tangled in fall into one of the pockets of the net. The banders check the nets about every 20 minutes, so a bird isn't tangled for very long. At the end of the morning the nets are taken down and put away so they aren't a hazard to birds. In addition to the nets, the banders set traps at ground level. The traps are kept in place all the time and are baited with seed so the birds know they can get food there. During a banding session the trap doors are allowed to shut on a critter that ventures inside, but at other times the doors are clamped open so animals can wander in and out. This morning we caught a vole in one of the traps. I didn't get to see it because I was with the group of people checking the nets.

But the first bird I got to see was caught in a trap! It was a California scrub jay (Aphelocoma californica) that had clenched its feet around the wire of the cage, making for a difficult extraction. Sophie, the intern wrangling this particular bird, had quite a job of it.

Sophie working to extract a scrub jay (Aphelocoma californica) from a trap
8 June 2018
© Allison J. Gong

The bird, once extracted from either net or trap, gets put into a cloth bag and taken to an area called The Yard to be worked up. Each bird gets the following treatment:

  • A complete formal ID, which can be really easy or really difficult
  • Banded on the left leg with a unique number
  • Sexed, if possible
  • Aged and life history stage determined. Age can be guesstimated by examining patterns of wear on the feathers. Missing feathers can indicate either a molt or some recent mishap in the bird's life. Some species are not sexually dimorphic, but females that are incubating or brooding have a patch of bare skin on the front underneath the feathers. Our scrub jay had a brood patch and is thus a girl!
  • Measured and weighed

The banding itself has to be done by either Martha or Breck. They are the ones with the training required to squeeze tiny bracelets around skinny legs.

Martha crimping band around the leg of a California scrub jay (Aphelocoma californica)
8 June 2018
© Allison J. Gong

It takes practice and skill to hold a bird immobilized but still able to breathe. You also have to avoid the feet, which are equipped with sharp talons. Elizabeth, the intern to whom Martha relinquished this bird for the remainder of the workup, neatly solved the problem of the feet by giving the jay a bag to hold onto. The bird's left leg, wearing the band, is tightly clenched and the right one is grasping the bag.

Scrub jay (Aphelocoma californica) with clenched feet
8 June 2018
© Allison J. Gong
Elizabeth examining a scrub jay (Aphelocoma californica)
8 June 2018
© Allison J. Gong

To examine the skin the handler blows up the feathers. To me this was surprisingly effective. I sort of assumed the bird's down feathers would be too thick to blow through. A good puff blows the feathers up and uncovers the skin.

Birds the size of jays are weighed in bags hung from a spring scale. The scrub jay in its bag weighed 90 grams. The empty bag weighed 15 grams, so the bird's body weight was 75 grams. The weighing was the last part of the workup, and after that she was released. Birds with an active brood patch are probably tending eggs or babies, and should be released in the area where they were caught so they don't have to expend a lot of energy flying back to the nest.

In addition to the scrub jay, we also caught a bushtit and a Bewick's wren. Bushtits can be problematic because they flit around in large flocks, and sometimes 20 or 30 of them will fly into the nets all at once. This results in a frenzy of activity for the banders, who want to work up the birds quickly so they aren't overly stressed. Breck said that while the data are important, the birds are more important, and if they have to let birds go without working them up, then they will. Bushtits are tiny birds--look at how small that wing is!

Bushtit (Psaltriparus minimus) getting its workup
8 June 2018
© Allison J. Gong

The last bird we caught was a Bewick's wren (Thryomanes bewickii). These little birds have a reputation of getting pretty tangled in the nets, because when they hit the mesh they start thrashing and making things worse. When I went out with Elizabeth to check the nets we saw the wren wrapped up in the net. It took Martha's expertise to get the bird free, and it screamed the whole time. That's a good sign, as a bird that complains is a bird that is angry rather than scared. Sometimes the net needs to be cut to free the bird, but this time patience and expertise were all it took.

Disentangling a Bewick's wren
8 June 2018
© Allison J. Gong
Bewick's wren (Thryomanes bewickii) in mist net
8 June 2018
© Allison J. Gong

 

 

 

 

 

 

A Bewick's wren is more substantial than a bushtit, although not by much. And it has a tiny leg that requires a tiny band.

Breck placing band on a Bewick's wren (Thryomanes bewickii)
8 June 2018
© Allison J. Gong

And the coolest thing is how they weigh these teensy birds. They're so small that they can fly around inside the bag, which means they aren't confined and would be unlikely to hold still long enough to get an accurate weight measurement from the spring scale. But years ago there was a company named Kodak that manufactured and sold millions of small plastic canisters that probably make up a significant proportion of landfill materials around the world. These little plastic containers happen to be the perfect size for containing the head half of a wren-sized bird, keeping the bird calm so it can be weighed.

Weighing a Bewick's wren (Thryomanes bewickii)
8 June 2018
© Allison J. Gong

Worked like a charm!

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