Across the Frozen Sky

Tundra swans’ long migration connects the isolated tundra to the urbanized mid-Atlantic.

As I laid out seed treats for wintering rodents–part of an ongoing capstone study on seed predation–a winter storm raged all around me.  Looking up, flurries of snow danced downward through the bare tree canopy around swaying tree branches in the freezing wind.  The sound of dry branches smacking and trees squealing as they rubbed against each other in the wind were the soundtrack for my hurried pace to keep warm and get out of the frigid and biting wind.

A flock of geese passed overhead, squawking against the wind.  I usually see or hear geese when I am here, likely a resident bunch that passes from crop field to crop field looking for scraps to scavenge.  A while later, I heard a different sound coming from the sky.  A soft, high-pitched ouoh ouoh sound rose from over the horizon to the North and then became louder and more distinct.  The chatter of a dozen or more tundra swans passing low over the forest filled the air and washed out the clashing and shrieking of the trees.  I heard the sound from my apartment a month before and darted out into the night, but missed any sight of them.  Now at least one flock passed directly overhead–pure white feathers against the grey winter sky.  With long necks outstretched and stroking the cold air with their wings each bird pressed on, and the V-formation of the flock sailed effortlessly out of sight.

Tundra swans, or whistling swans, are similar to most other North American swans in appearance: white feathers, a dark bill, and long neck.  Patches of yellow at the base of the bill help distinguish the tundra swan from the native trumpeter swan (with a solid black bill) and often domesticated mute swan (with an orange bill and black base).  The tundra swan’s call is much less nasal and harsh as the trumpeter swan.

Tundra swans breed in open sites across the northern edge of landmasses in the American and Eurasian Arctic.  In North America, flocks gather in large northern lakes after breeding and before embarking on a long autumnal migration across Canada.  Wintering grounds in the west include scattered large lakes, agricultural areas, and the Pacific coast.  In the east, the Great Lakes and, to a greater extent, the Chesapeake Bay regions are suitable wintering grounds.  In the winter, tundra swans feed on shellfish and grains from crop fields.  Before migrating north again in early spring, young tundra swans form mating pairs and older birds reinforce their lifelong bonds.

I marveled at the passing flock and their remarkable journey across the frozen sky.  It is inspiring to witness a few dozen creatures on their way from far-flung wild regions to the developed Atlantic coast.

While only a few months old, birds born and raised on the remote and ephemerally green tundra landscape must be ready for a migration of hundreds of miles or risk starvation and freezing.  Flying mostly in the cover of night, the swans pass over the Taiga–the great coniferous forest belt encircling the Arctic–and twinkling lights of inland cities and towns.  Their soft calls to each other are as much an encouraging cheer to press on as a distressed panting during their marathon flight.  The flocks that arrive in the Chesapeake Bay area spend their winter just offshore of the most heavily urbanized area in the United States.  Tundra swans thus connect the remote Arctic tundra to some of the most densely humanized landscapes on the planet with their migration.

Witnessing these impressive birds during their flight brings a sense of wildness to the tame eastern forests. Tundra swans’ incredible voyage is rooted in an enduring history of survival.  The nomadic lifestyle of many migratory animals–monarch butterflies, pronghorn antelope, and salmon–is only possible if stable habitats are maintained along their migration route and on breeding and wintering grounds.  For tundra swans, the isolated Arctic tundra and the urbanized coast are contrasting environments that the determined birds call home.

The Herbarium: Mounting

October 2, 2017

Dr. J,

Last week, I continued to sort through various Polygonaceae family members.  I ran across several from arctic regions including Koenigia islandica, whose name suggests a warmer climate than the Alaskan archipelago where it is native.  Another, Oxyria digyna, is a unique little plant that can be found both in the arctic regions of the north and in alpine habitats further south.  This makes sense as the two habitats are similar, yet the plant can be seen exhibiting different growth forms between the two habitats.  Arctic plants are more likely to reproduce asexually and alpine plants tend to produce more seed.  Perhaps this difference is related to the number of pollinators available in Arctic vs. alpine regions in California and Colorado.

I met one of the mounters on Thursday.  Bonnie walked me down to the lower herbarium—the collection is kept in two rooms on two separate floors—to meet Helen and witness the mounting process.  Helen stood at a table with a paintbrush in her hand hunched over a specimen sheet.  An AM/FM radio tuned to WQED station was blasting classic music just loud enough to disturb the neighbors (if they were any).  Helen is an 85-year old retired jeweler and has been working with the herbarium for many years.  A flat school lunch tray held a pool of diluted Elmer’s glue which Helen dabbed onto thin strips of adhesive paper.  These strips held the pressed plant to the specimen paper.  She also dabbed some glue on loose ends of the plant and pressed these against the paper.  Helen is meticulous.  She carefully glues down every bit of plant so that a strong gust of wind would fail to loosen even a leaf.  She showed me the appropriate way to lay the leaves—so that at least one leaf underside would show.  Her attention to detail as well as the pace at which she worked were impressive.

Helen told me that she got her start as a volunteer and that eventually she was asked to work for pay a few days per week at the museum.  The mounting process seemed fairly straightforward, but it does require a certain level of diligence.  Helen would take the loose bits of leaf, stem, and seed that were dislodged from the specimen and pack them into a miniature envelope.  The envelope was then attached to the appropriate specimen paper.  Helen remarked that saving these small pieces is important.  Her dedication to the herbarium is something that I admire.

Having volunteers and personnel with particular skills, such as Helen, is important to institutions like the museum and herbarium.  Helen may not have the skills required to collect and identify specimens, but she can provide for the herbarium by mounting collected specimens.  After sifting through specimens that she may have mounted, I’m glad that I had the chance to meet Helen and witness her skills in use.


Postscript:  Helen’s technique is commonly seen in many of the specimens at the museum, but I have also seen other ways of fashioning specimens to herbarium paper (a heavy duty paper 11 x 16 inches).  Wire poking through the paper can be an effective fastener and may be good for an artistic use of pressed plants in temporary displays.  The type of glue used varies, however, thicker hot-glue may be too unyielding for a specimen and cause stems and leaves to crack.  Elmer’s and paper strips seem like a good option and are easy to find and cheap to purchase.

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