The Dippers and the Caddisflies

By Nancy Partlow

I took my Dad to Tumwater Falls Park recently. I wanted to show him the Canada goose that was nesting in the wood pile atop the upper Deschutes falls. As I rolled him in his wheelchair to a platform overlooking the river, I glanced down and right in front of us I saw my favorite bird – Cinclus mexicanus, the American Dipper.

It was hunting from atop a log - diving quickly in and out of the swiftly flowing water behind the falls. I knew it must be feeding young, but there were no babies apparent in the immediate area. Dad and I were both amazed at how fast the bird was jumping in the river, retrieving its prey, knocking it on the log, and diving back in again. We couldn’t figure out what it was going after. They didn’t look like salmon smolts, which I had seen a dipper gathering in abundance last spring at the lower falls. What could they be?



The next morning I returned to the platform to check out the goose, which was still incubating eggs, and briefly caught sight of a Spotted Sandpiper flitting off the woodpile. Then, as I had hoped, the dipper returned to the log, this time with a baby. 


The bird resumed its activities of the previous day, but now with my zoom camera, I was finally able to figure out what its prey item was – fat, juicy caddisfly larvae. 


I was excited. I remembered learning about Deschutes River caddisfly larvae as a youngster. My brother, a fisherman, had shown me the clever little houses called “cases” that these aquatic insect grubs create out of the river-bottom materials of teeny pebbles and sand. It was one of those “isn’t nature amazing” moments that stick with you for the rest of your life. And here was the dipper eating them. There must have been hundreds of these creatures submerged beneath this small stretch of river because empty caddisfly cases littered the log’s surface. 



Fascinated, I watched as time and again the parent grabbed a larva by its head (the only part of the insect sticking out of the case) and banged the case on the log until the bug inside was knocked insensible and relaxed its grip on its only source of protection. The bird did this several times in a row until it had gathered up a mouth full of grubs, which it then unceremoniously stuffed down the gullet of the loudly-begging baby dipper.

Occasionally the caddisfly worm was so far inside the case that the dipper couldn’t grab its head. When that happened, the bird would take the whole case in its beak and knock it on the log to dislodge its tenant. 


Other times it tried unsuccessfully to poke its beak into the case to grab the recalcitrant food morsel inside.



Obviously, dippers have a well-honed search image for such underwater prey, no doubt aided by the protective shields on their eyes called nictitating membranes. Many people mistake the dippers’ striking white eyelids for these membranes, but bird authority David Sibley dispels that notion.



All of the parent bird’s feathers were worn from months of indefatigable use, but in spite of this, the dipper was singing! 


Dippers are America’s only aquatic songbirds, and this one was showing off its vocal prowess; perhaps teaching its baby how to sing, or maybe just warbling its exuberance at finding such a great food source. Whatever the reason, it was fun to hear.

Naturalist John Muir was enamored of the American Dipper, which he called the Water Ouzel, and wrote extensively about it. His description of its song is pure poetry:

The more striking strains are perfect arabesques of melody, composed of a few full, round, mellow notes, embroidered with delicate trills which fade and melt in long slender cadences. In a general way his music is that of the streams refined and spiritualized. The deep booming notes of the falls are in it, the trills of rapids, the gurgling of margin eddies, the low whispering of level reaches, and the sweet tinkle of separate drops oozing from the ends of mosses and falling into tranquil pools. 



The tranquility of the two dippers in front of me was abruptly ended when a crow landed nearby. All singing stopped, and the dipper baby, which had been bobbing incessantly, froze in place, becoming the proverbial bump on the log.

The crow, which seemed more interested in what the dippers were eating, soon moved on, at which point the baby tentatively explored the more placid waters next to the log. I enjoyed watching it learn how to become a dipper.



The next day when I returned to the park, I saw the parent dipper foraging the rapids below the upper falls, trying valiantly to keep two persistently-begging babies fed.

The parent was not nearly as successful in finding food as the previous day, and was too busy to sing. 
The water above the falls was noticeably lower and clearer, revealing a cobbled river bottom with no caddisfly cases to be seen.

Perhaps the dipper had hunted them all out. Hopefully, by next spring there will be another bumper crop of these intriguing insects to feed the next generation of dippers at Tumwater Falls Park.

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All photos and videos by Nancy Partlow
(Highlighted text leads to videos.)

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Resources: 

Dippers must be pretty tough to survive the constant battering of their dynamic environment of cold, fast-moving water. Their range extends into northern Alaska, where they are able to endure temperatures down to 20 degrees below zero. A friend recently told me that the first time he ever saw an American Dipper was in a stream at Paradise in Mt. Rainier National Park.

Here’s a photo that gives a sense of how resilient these birds are:


http://www.flickr.com/photos/61210501@N04/6456463295/in/photostream/



Here are a couple of truly gorgeous images by photographer Eugene Beckes of an American dipper with caddisfly larvae in its mouth:
http://www.flickr.com/photos/61210501@N04/6425042809/

http://www.flickr.com/photos/61210501@N04/6320238965/in/photostream/





 



Along the Shores of Puget Sound

It was over fifty years ago that I was a child, beach combing at my great-uncle Wilmot’s bay place on the western shores of Budd inlet. He had a small sliver of land along Little Tykle cove. It was a scary twisty road through a narrow ravine down to his place; those dripping fern-choked hillsides washed down rich sediments each winter into the bay. This created a fertile tidal estuary: it was as if nature herself set a banquet table for all of the marine life of the bay...

Little Tykle Cove, (Olympia, WA)

Shirley Patterson, circa 1930

I loved beach combing along these muddy shores. I came to it quite naturally: my mom Shirley also grew up along Budd Inlet and was an addict for agates and shells. Every low tide in summer she and my grandma would stuff all us kids into my grandma’s 1957 blue VW van and we’d tootle “down to the bay”, where we spent hours exploring the life of the mudflats. My mom was a self-taught beach naturalist and it was to her I would take my treasures and questions about what I saw. She always knew the answers; this magical beach world was as much home to her as it became to me.

One of my all time favorite shells are the Slipper Shells. These are pretty odd shells, fairly ordinary on top but when you turn them over, you see a thin half shelf inside. They were uncommon on Uncle Wilmot’s beach, but I learned to find them in one particular place right on the edge of the Little Tykle Creek as it emerged into the gravel-mud beach. To me these shells were profoundly magical: I thought of them as Faery shoes. Sometimes we also called them cradle shells and I imagined the Faery, packing their youngsters into these shells and floating them off under the starlight night...

Now some fifty years later, I am reviving my passion for beach combing. Here in the southern end of Puget Sound, we are fortunate to have a group called South South Estuary Association*.   For the past few years they have trained enthusiastic volunteers to be beach naturalists. These people take shifts at low tide in summer at several of our local beaches: these include Tolmie, Burfoot and West Bay Rotary park. Here the next generation of young beachcombers can come, pick their way around the tidal mudflats and also have access to people like my mom to help answer questions about the rich diversity of life.

I have joined the beach naturalists and am currently in training. We were asked to pick a “critter” and do a talk on it. I immediately jumped on the slipper shells. Here is what I found:

They are a kind of mollusk, known as a gastropod (stomach foot). They start out life as tiny larvae swimming in the plankton, but after about three -five weeks in the sea, they drop down to the sea floor, living in the deep sub tidal waters where we are unlikely to find them except in the lowest tides. Here they attach to some hard surface, growing into the snail that lives in this unique shell. And where they drop out is is generally where they spend the rest of their lives. They may live up to 10 years.

Slipper shells on a Moonsnail

They are filter feeders. When the plankton-rich tide comes in, they ooze out a fleshy mantle under their shell. This mantle produces mucous to which food particles can stick. They use cilia to reel these food particles back into their radula (tongue) and digest them. As long as they have access to a rich plankton source, they are good to go ( or stay, as in this case).

They attach to all kinds of hard surfaces: rocks, floats, pilings and other shells. Here is picture of several of them attached to a Moon Snail, another common marine animal on our beaches.

There are several species in Puget Sound. Probably the most common is one from the Atlantic beaches that was introduced with non-native oysters. This one with a white chalky outer shell is called Crepidula fornicata, a highly suggestive name which refers to their life habit as sequential hermaphrodites. The way it appears to work is that a female lands on the hard surface first. A male then comes along and attaches to her.

Cluster of Slipper shells, off Cooper Point, (Olympia WA)

Then other males may come along as well, attaching in turn until you can see quite a large pile of slipper shells. This system works well for reproduction: the animal has everything it needs right there and doesn’t have to move. However, if the female on the bottom of the dog pile dies, the other slipper shells have the ability to change sex! This is remarkable system.


The Atlantic species C. fornicata is quite numerous along the eastern seaboard. While they live in the deep intertidal waters, once they die their shells are cast up on the beach. Here is a photo published by "Maggie's Farm" from along the Connecticut seacoast, where literally thousands of slipper shells have washed ashore.

Slipper shells on a Connecticut beach, cast up by winter storms.
http://maggiesfarm.anotherdotcom.com/archives/19620-Slipper-Shells.html

It has been years since I visited Little Tykle Cove, but recently my cousins inherited the place and moved back in. So my sister Nancy and I went down to visit; I knew exactly where to look for Slipper Shells and indeed I found them, right on the bank of Little Tykle Creek. That was a wonderful moment: it took me right back to my childhood, to those hours spent roaming that beach, learning from my mother and having my first naturalist seeds planted in me. My mom has now passed on, but somehow I just know she is having a great time exploring the tidal beaches of heaven, finding all the best shells and looking forward to the time when she can show them to me... .

Janet

Resources: South Sound Estuary Association http://sseacenter.wordpress.com/ 
Photo of cluster of slipper shells by Wendy Eklund

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* South Sound Estuary Association is a local jewel.  They have lots of wonderful (free) education about our local estuaries.  They offer regular summer low tide walks, staffed by volunteer beach naturalists.  They lead monthly Pier walks at Boston Harbor marina, where at night a light is lowered off the dock:  all kinds of amazing creatures are drawn to the light.  There are local experts and volunteers who answer questions about what is seen.
      They also have a small building down by the Farmer’s Market at 608 Washington NE, Olympia.  Here for a small entrance fee you can visit this "estuarium" and see the salt water tanks, full of the wonderful creatures of Puget Sound.  Highly recommended.
     They are planning on moving to a larger facility on State Street, probably later this summer.  They are in the process of raising money and donations are always welcome. You can check their webpage at  http://sseacenter.wordpress.com/ to find beach walk schedules, Pier night schedules, Estuarium hours and ways to donate. 

Geese in the Woodpile

By Nancy Partlow

At Tumwater Falls Park a few weeks ago, I saw a goose wandering around the log jam at the top of upper Deschutes Falls.  It was such an odd sight that I had to take a second look. As I watched the goose settle into a certain spot, it occurred to me she might have a nest there.  Sure enough, when I looked through my binoculars, she was firmly ensconced atop a mound of carefully arranged sticks she had built to incubate her eggs. 

The next day I brought my Dad to see the goose.  At 96 years old with limited mobility, he doesn’t get much of a chance to experience wild nature these days.  I gave him my binoculars and pointed out where she was on the woodpile, since with her coloration she was very cryptic in that setting. 

We both enjoyed observing the bird through binos and camera screen, especially when she stood up in the soft, goose-down lined nest and gently turned her eggs to ensure even warmth from her breast. 

A few days later I returned to see if any of the babies had hatched, and was excited to note that she had three babies beneath her and some still-unhatched eggs in the nest.

I was kind of worried though, because throughout this whole thing, I had never seen a mate for the mother goose.  Could she raise a whole family on her own?

A couple days later, we were surprised to find the nest empty.  There were two adult geese poking around the nest, but no babies in sight.  What had happened to them? 

Just as we were about to leave, my Dad said, “There they are!”  The whole family was together; mother, father and six yellow, cute-as-could-be feather balls. 

      

The gander was very protective.  When two other geese, curious about the new babies, paddled near the nest, he pursued them up the river in an explosive fury of wings and honks.                                                   

The babies stayed near their mother, forming a tight little scrum whenever she moved away a few feet.  But as the mother moved around the woodpile, the babies followed her, struggling their way over the jumble of branches and sticks.  When she rested, they formed a beautiful scene.

I felt honored to have witnessed this process.

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All photos and videos by Nancy Partlow

Life Underfoot ~~ or ~~ The Pyramids of Beeza

Last Spring I was introduced to an aggregation of solitary bees nesting underground, in the lawn and landscape of an Olympia area home.  I was able to watch it regularly last year and this year have observed them a few times more.  The population remains robust as does my fascination for them.  While I have not actually counted, I suspect that there are tunnel entrances near a hundred.

I have learned a lot about these bees in the past year.  Tempting to describe this population a "colony", this inacurately suggests (at least according to bee experts) that there is organization and leadership.  So instead a massed population of solitary bees is called an aggregation -- a build-it-yourself housing complex minus the manager.  This aggregation that I'm watching starts where a concrete driveway and gravel parking bed borders a casual, mowed patch of lawn.  Along the gravel parking the (human) residents have placed lengths of round red timbers as a decorative border. Under the timbers the bees push and dig their way along the board and then continue excavating into the soil. Elsewhere are telltale soil mounds that surround each entry and these wonderful little pyramids, called tumuli, (singular: tumulus) extend several feet from the driveway edge into the lawn and garden beds.

It surprises me as to how many years I took for granted the many little mounds of dirt in garden edge and sidewalk crack, of life underground.  Admittedly they are mysterious and a bit frustrating.  Last year Janet and Nancy and I sat with these bees for an hour watching them, and Nancy and I each tried with only modest success to photograph them. These bees circle and circle several holes, forcing us into a guessing game of which hole to watch, and then "poof" the bee vanishes down one of them.  This year I tried again. Blurry as these photos may be, they are for now our best.

Look close - an ant "hitchhiker" on this one's back.
The bee did not fly until after the ant disembarked.

Identification of ground nesting bees begins with how the bee forms her individual nest cells and what physical adaptations she possesses for building underground. Some bees are easy to identify on the wing and in the flower.  Many are not.  Some are bigger than a honeybee, many more are very small.  Of the thousands of species of bees in the world, 70 percent are said to nest in the soil.   Seventy percent!!  That means that even in western Washington there likely are several dozen species of ground nesting bees. 

Bee approaching ground nest. Nancy Partlow 2013

The three main ground-nest building families (in North America) - Andrenidae, Halictidae, and Colletedae, are separated by very different UNDERGROUND habits.  Identification often requires a microscope, a shovel, or both. 

• Halictidae includes sweat bees, are usually very small and metallicly shiny.  Many are communal, sharing a common entrance and for a few there is even some shared provisioning and patroling, though usually every female is an egg layer. Some do not nest in the ground.

drawing from UC Riverside 2003 webpage
 adaped from from Stephen et al., 1969
UCR link no longer works.

• Colletidae bees are a "short-tongued" solitary bee and and also called polyester bees, because they coat each cell wall with an organic polyester that becomes a waterproof sack.  Using glandular secretions, she paints the cell with her very distinctive tongue.  She provisions into the sack a wet mix of pollen and nectar, lays one egg, and seals it up.  Often the food mass is soupy and the egg may be attached to the sack above the food. 

• Andrenidae bees are a "long tongued" ground nesting bee.  The female plasters a (different) glandular mix onto the cell wall with a special paddle part of her hind end; her mixture glues the soil together.  The food mass is typically more solid than Colletids.  Some andrenids are parasitic "cuckoo bees" that rely on others bees to build and provision nests that they then overtake.  There are many different species of Andrenidae bees; the subject of this blog is probably one. *

There are other groups of bees that also nest underground.  Bumblebees often nest in the ground, depending upon what they find that suits them, and have different habits.

When a year ago I started watching these bees I also started this post, then set it aside.  Perhaps it is a character flaw, but if I'm going to write about some creature and pretend that I know something, I want to be to able to identify it at least to family and hopefully to genus.  Here it is, a year later, and still I remain unable to put a name to this bee.  In this last year it did become a minor mission to learn more about mining bees.  The mission will continue.  And, while I still have not identified the subject of this post, I am at least more at peace with my public ignorance.

Glen

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* I have since learned from fellow bee friend Rusty that this is indeed an Andrenid bee. Getting this bee to Genus will have to do, is where our knowledge stops, is as far as her informant is willing to go.  If pressed, we might be able to narrow it down to one of a dozen or two possiblities, based on location, size, etc., but I am pleased that I can get this far -- and presently not driven to go farther.

Visit Rusty Burlew's page http://www.honeybeesuite.com/andrena-mining-bees/ for better photos and more detailed info as to why these are Andrena.
GB 5/23/14

Bugguide - Native Bees of North America

Photos Glen Buschmann unless otherwise credited.