20. Sphyrapicus ruber

IMG_2385January 5, 2017

Chatter of House sparrows filled the back yard at 3:30, an hour before sunset. Their quick shifts perked up trees, shrubs and the ground. A Bewick’s wren clambered and poked on the bark of a trunk. A junco flitted through the garden. In the park a Song sparrow employed its two-footed hop-scratch in the leaves under the birch, and robins enlivened lawn and trees.

By 4:00 sun lit only the treetops, kindling seed cones orange on the Douglas fir at the far end of the park. Bare twigs of the garden thicket did not hide the towhee sitting inside. I reminded myself to open to this place, to make the small motion of mind that brings me alive to it.

By 4:15 sun was gone from this east-facing hillside, but still lit up the tallest poplars in the valley bottom. The Bewick’s wren, Song sparrow and towhee continued to work the back yard. New action high in the horse-chestnut tree caught my attention. A woodpecker was breaking into the globe of a large wasp nest from last summer, ripping and flinging bits of paper. In twilight I saw white markings down a black back. Almost all of the bird’s head appeared dark red. A Red-breasted sapsucker. Last week, at New Years, Sherryll and I watched one beside a trail.

She insisted that I stop and look. Our walk had just begun and myGoals-Fitnessapp was tracking an 8K session. I didn’t want to stop. I know what’s good for me though. Sherryll is a strong walker, but she pauses along the trail to thank individual trees and birds, which annoys me but helps me see. A woodpecker at the path’s edge was gleaning in the bark of an alder, not shy of us, combing for insects. On my iBird Canada app I tapped “British Columbia”, “Tree-clinging-like”, and “Medium (9-16 in)” and got seven matches, woodpeckers. All had markings of red or yellow around the head, but only Red-breasted sapsucker had the entirely red head and throat. We watched until the bird moved into the woods out of sight.

So today I recognized the Red-breasted sapsucker demolishing the wasp nest. Recognized rather than identified. A ten-year-old girl made that distinction in a radio interview I heard recently. She had just completed a birding “big year”, seeing or hearing 227 species. She said that birders prefer to “recognize” rather than “identify” birds. It’s like the difference between identifying a suspect in a police line-up and recognizing a friend on the street. This winter in this yard, most of the birds feel to me happily familiar. This is their place and mine, and I recognize myself at home with them.

I don’t expect to see a Red-breasted sapsucker here often. Birds of Victoria and Vicinity describes it as uncommon in the area and rare in the city, preferring rural woodlands. The Naturalist’s Guide to the Victoria Region directs us to damper locales, west toward cedar and hemlock rainforest or north to mixed fir and maple woods. Winter is probably our best time to see them in town.

This winter the Audubon Christmas bird counters in Duncan, 50K up-island from Victoria, saw BC’s highest number of Red-breasted sapsuckers. Thousands that nest in the interior of the province move out to the coast in autumn, while those that breed here around the Salish Sea remain resident year-round. I would guess that the individual today at the wasp nest was a migrant from the interior, wintering on the coast, seeking insects and suet blocks in the neighbourhood. Does it also maintain sap wells around here somewhere?

Sapsuckers consume tree sap in all seasons. The BC interior, where sap freezes in the trees, cannot serve as winter habitat. Even on the coast, prolonged icy weather in some winters can be deadly. The number of Red-breasted sapsuckers in the province fluctuates extremely, and appears to crash in years with extended cold snaps on the coast. Researchers Wolf Ziller and David Stirling reported on a possible example of such a population disaster on the islands of Haida Gwaii. In 1950 the mean January temperature at the town of Masset was -50C. (230 F.) In an article for the Forestry Chronicle (1961) they note:

“Sapsucker holes drilled at the base of large hemlocks on Moresby Island indicate that the birds were attempting to find food by pecking through thick bark near ground level where cambium was not yet frozen.”

Normally, Red-breasted sapsuckers excavate their sap wells in thinner bark, higher and on younger trees. Walkers in woods on Vancouver Island often see the pattern of square holes they carve. It begins as a row of short slits across the trunk. Each slit pierces the bark to the layer of phloem cells that transport sap. The bird eats the phloem and scoops the liquid that oozes into the slit. The sapsucker tongue has evolved with a brush at the end for licking. They should be called “saplappers” really.

The Red-Breasted, Sphyrapicus ruber, regularly works a circuit of many wells on several trees. It slurps accumulated sap and gradually enlarges the slit into a rough square, resulting in a row of squares across the trunk. As they run dry the bird cuts new slits below. Many rows of squares gradually extend in columns down the trunk. If you see that pattern on a tree hereabouts, Sphyrapicus ruber almost certainly engraved it. The species’ closest cousins, S. varius, Yellow-bellied sapsucker, and S.nuchalis, Red-naped sapsucker, leave similar traces on trees, but rarely stray onto Vancouver Island.

For nesting, the three sapsucker cousin species have BC nicely divided among them. The Red-breasted population centres in mild coastal climate, in coniferous rainforest such as at Haida Gwaii. Yellow-bellied sapsuckers breed mainly in boreal forest of northeastern BC, and migrate far east and south for winter. Red-naped sapsuckers prefer aspen groves of the dry southern interior for nesting. They winter in the US southwest and Mexico. Our Sphyrapicus ruber’s breeding range overlaps with both other species in hybrid zones.

Able to interbreed successfully, ruber, varius and nuchalis were officially lumped until 1985 as races of Yellow-bellied sapsucker. Why did the American Ornithologists Union award Sphyrapicus ruber its separate species status? The more I look into the question, the less simple the answer becomes. Scientists use the term “species” rather pliably, it turns out. Various definitions and standards may apply.

Red-breasted sapsucker defies the most common definition of “species” by interbreeding with Yellow-bellied and Red-naped, and producing fertile offspring. The hybrids can successfully breed. Ruber, varius and nuchalis gene pools do not remain fully isolated from one-another.

Genetically, Red-breasted and Red-naped sapsuckers are the most alike of all bird species. The similarity of their genes would better qualify them for subspecies status. Ruber, with its deeply red head, looks strikingly different from nuchalis, but merely reducing the amount of red carotenoid pigment in ruber’s head feathers would produce an almost typical-appearing Red-naped sapsucker.

Scientists believe that, ruber, nuchalis and varius have been diverging during and since most recent Ice Age. That period contained colder and warmer times, glacial advances and retreats. Variations in climate and ice probably separated the birds’ breeding ranges at some times, but allowed merging and mixing at other times. Around a million years ago, common ancestors of Red-breasted ruber and Red-naped nuchalis began to differentiate from ancestors of Yellow-bellied varius. Later, maybe 500,000 years ago, ruber and nuchalis started to sort apart from one another. Recently, 25,000 to 11,000 years ago during the last glacial advance, isolated populations of Red-breasted sapsucker likely persisted in refugia on Haida Gwaii and Vancouver Island. In warmer climate since then, ruber’s breeding range has intersected again with its cousins, allowing some flow of genes among them.

Calling Red-breasted sapsucker a species recognizes that it has passed a point of no-return in differentiating from its cousins. Genetic mixing among them tends to stay in the hybrid zones of range overlap, not spread much into the wider populations. The hybrid birds seem not to fit in well. They are less successful at passing their genes along to the next generation. Ruber’s distinctly red head may be a factor. Red-breasted sapsuckers prefer mates that look like them. Another factor might be spring migration habits. Ruber has its own timing for arrival in its breeding areas and for courtship. Also, it is distinct ecologically from varius and nuchalis. They do not share Red-breasted sapsucker’s intrinsic fit in coastal rainforest community. The whole package of differences – appearance, physical structure, body chemistry and behaviour – separate Sphyrapicus ruber enough for the American Ornithologists Union to call it a species.

That term has posed a problem for science ever since Charles Darwin’s book On the Origin of Species changed our understanding of how living things come to be. Darwin recognized the problem:

“I look at the term species as one arbitrarily given for the sake of convenience to a set of individuals closely resembling each other…. No one definition has satisfied all naturalists: yet every naturalist knows vaguely what he means when he speaks of species. Generally the term includes the unknown element of a distinct act of creation.”

People need common agreement about the different kinds of beings and their names. Prior to 1859 we knew that a “species”, any distinct kind of being, had been created complete, on-the-spot, at-the-moment. Since Darwin and Wallace we know that becoming a distinct kind of being is a process. It advances over centuries or millennia. Speciation is a long conversation in which a physical environment, its living community and a new idea are tussling, modifying, attaining a good enough match-up to become a long-term habit.

Our wet Northwest coast environment, its rainforest community and the Red-breasted sapsucker idea have worked out their fit. Each defines the other. Sphyrapcus ruber has become a keystone species here. Its sap wells contribute food to at least forty-eight bird species, six mammals and dozens of arthropods. Hummingbirds literally follow the sapsucker on its route around its wells, both for sap and for insects it attracts. Availability of sap wells may affect winter survival for Anna’s hummingbird, and migration routes and timing for Rufous hummingbird. Red-breasted sapsucker nest holes provide nest and roost sites for many forest vertebrates. Tree swallow and Violet-green swallow populations depend on them, and Northern flying squirrels may also.

The sapsucker also helps renew mature forest. Sphyrapicus ruber prefers to excavate sap wells in trees that are already unhealthy. The wounds allow fungi to inoculate and hasten decay. Punctures through the bark near the ground in mature conifers, such as Ziller and Stirling described in Haida Gwaii, can let in fungus at the roots. The rot causes giant trees to fall, which opens gaps in the canopy. A burst of new growth results in the openings and maintains diversity in the rainforest community.

Becoming a species is more about linking than separating. We might view speciation as a process in ecosystem for expanding the community’s network of interdependence, its variety and complexity. Same with individuation in humans. We become uniquely ourselves in the give-and-take of matching-up with family, community and place. I modify and discover myself as Sherryll and I negotiate a walk in the woods and a stop to watch a sapsucker, as I garden with native habitat in the yard, the park, the valley, the streambank, as I fight for it, labour with the other gardeners, and include Fuller and Emma.

Next morning I go out to dump compost on the pile. The sun isn’t up yet. From the fire escape I recognize an Anna’s hummingbird tick somewhere above me and a Bewick’s wren rasp somewhere below. We’re home.

19. Melospiza melodia

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January 3, 2017     9 a.m.

A tenor on the Christmas playlist was singing In the Bleak Midwinter, and the yard outside the living room window did look chilly and bleak. A feeding flock of little birds was filtering through. Bushtits swarmed the suet block that hangs from the clothesline. A towhee on the lawn below it collected bits that showered down. The bushtits dispersed from the suet cage and a sparrow landed. Not one of our everyday regular sparrows at the feeder. Those are plain grey underneath, but this one had brown streaking that converged on the breast into a dark spot. A Song sparrow. I had been hoping to see one in the yard.

Midwinter is a good time to see Song sparrows around the Salish Sea in back yards. Fall migrants converge from the interior of the province and from the northern coast. Many move through, headed for Oregon or California, but many stop here at the southern end of the Island and join feeding flocks with other little brown birds.  So the Song sparrow this morning at the suet cage was likely a winter visitor.

But it might have been a local resident. Various races of Song sparrow, Melospiza melodianest in British Columbia and coastal Alaska. Ours on the southern coast, Melospiza melodia(morphna), mostly remain here year-round. Soldiers in World War II found coastal resident Song sparrows wintering even on Attu, the extreme northwestern island of the Aleutian chain in Alaska. In the journal article Winter Birds of Attu(The Condor,March 1946) George Sutton and Rowland Wilson reported on the Aleutian subspecies, M.m.(sanaka):

“We saw these interesting finches daily. Even during the wildest gales one or two of them stayed around the door of our barracks, looking for something to eat. Most of them lived along the shore, spending virtually all their time between the water’s edge and the snow – a coastal strip varying in width from a few feet at high tide to a hundred yards or so at low tide.”

On sandflats at low tide, the Attu Song sparrows joined flocks of sandpipers feeding on tiny snails. Some pairs maintained territories over winter among gasoline drums in US Army scrap heaps. Sharing the shoreline with people was normal for subspecies sanaka. In past centuries human villages thrived on Attu. Winter snow pushed people and sparrows both into the tidal zone to forage among the sandpipers.

Evolving to survive winter in the bare strip between ocean and snow probably helped our Pacific coast Song sparrows through the most recent Ice Age. Research suggests that resident populations of Melospiza melodia survived in coastal refugia where glacier halted short of the shoreline. Song sparrows likely persisted on Haida Gwaii seashore, and possibly on Vancouver Island’s Brooks Peninsula, as tidal zone specialists. When glaciers melted around 15,000 years ago, refugium birds probably colonized much of BC and the Alaska coast. Humans may have spread out from the refugia also.

I watched a Song sparrow at the shore of Portland Island near Victoria in August. Sherryll and I enjoy rowing out and camping there. At the Shell Beach campsite, families with kayaks tented around us. On dry sand beside a log on the beach a little brown bird tilled a moist-dark furrow. A double hop with both feet uncovered beach fleas and set them jumping. The bird gobbled them where they landed.

Next morning in the tent, at the edge between prayer and sleep, a canoe prow glided into my left peripheral vision just off the beach. No one paddled the wide, long canoe, carved of wood, sliding past. Old people stood in it, maybe fifteen of them. Fear was my first response. An omen! My overloaded rowboat would sink perhaps and I would join those old people. But no. Those were Elders. Shell Beach campsite, over many generations, was their seasonal home. The sand where my rowboat sat aground on the early morning low tide was their clam flats. Shell Beach retains, I choose to believe, its long human consciousness.

Drowsing again I heard a moment of voices that laughed and sang, and a tool that repeatedly knocked. Left peripheral vision glimpsed people working, maybe six or ten of them, back on the shore toward the trees, maybe an extended family, maybe putting up a shelter. A woman generated fun in the task as she worked, with joking and singing.

I left the tent to jot notes at the picnic table. Predawn, two kayakers quietly packed for an early start. Deep motor rumble crossed the water as the first ferry emerged from Fulford Harbour. A seagull and a crow had their say; a raven croaked and two glided over the campsite. Families slept in their tents: children, parents and a grandpa. Shell Beach remains a place of families and their shelters.

That woman I glimpsed drawing her family’s energy into a common task with fun – she stood also, I imagine, among the Elders in the big canoe. The human is a social animal. Elders want community to thrive, whole community, including the sleeping people and the sparrows on the sand flat.

Our local Song sparrows are less social than we. Melospiza melodia(morphna) focuses fierce attention on individual territory, lifelong, summer and winter. We have studied their habits closely for many years. The most studied of all Song sparrow populations inhabits Mandarte Island, a few kilometers from Portland Island. Passengers on the ferry from Sidney, BC to Anacortes, Washington have noted Mandarte Island as the huge white rock, bare of trees, with some colourfully-painted shacks and many old outhouses. The outhouses are in fact observation blinds for researchers. They have occupied the shacks every summer for several decades.

Mandarte Island ecosystem over millennia has included seasonal human visits. From ancient days we landed to dig camas bulbs and shellfish, and to gather seabird eggs. Maps label it also as Bare Island Reserveand it belongs to the Tsawout and Tseycum First Nations. Satellite images reveal Mandarte as a colossal sea-cucumber, stranded and petrified as white sandstone. A central groove down the length of the island (700 metres) grows thick with shrub. Zooming-in on the picture from space shows the paths researchers tread in the shrub to locate every Song sparrow nest each year. I won’t ever visit Mandarte Island physically, so I appreciate the satellite image perspective and intimacy.

And I appreciate the book Conservation and Biology of Small Populations: The Song Sparrows of Mandarte Island(2006). UBC professor Jamie Smith and other editors assembled research from five decades. Life is brutal for those birds. Habitat on the big rock imposes strict population limits – breeding territories for no more than 150 Song sparrow pairs. Excess population is controlled mainly by death of juvenile birds. First-year birds vie for status. The winners, the most dominant, have most access to food and the best chance of securing territories and mates. Winter survival is highest for birds paired in territories. Song, particularly for males, is a weapon in their battles. Singing is a life-and-death fight.

First-year males on Mandarte learn their songs largely by listening to adult territory-holders. When he leaves the nest the young male floats among nearby territories. He quietly copies adults and engages in singing contests with his age-mates. By September or October he may stake his claim and wrest his piece of the rock. He takes the fight to territory-holders around him, and perching centimeters away, bashes them with his song repertoire. Entire songs that he learned from an adult male, he may fling back at its owner. The confrontation might last two days. Beak and claw fights can result, but rarely. The young male might or might not succeed in singing-back opponents from the borders of his new territory. If he fails, he may resume his marginal existence as a floater. If he survives winter as a floater, he can try for a territory again in early spring.

Singing ability reflects the overall quality of the bird, research suggests. On Mandarte Island, males with the largest song repertoires typically win territories soonest, maintain them longest, live longest, attract females most strongly and contribute most descendents to future generations. Females also work out their dominance hierarchy, but researchers have not yet studied it as thoroughly. By October, a juvenile female who does not succeed in pairing with a territory-holding male has virtually no place on the island. Winter mortality or emigration removes them. In the yard here, the suet block may sometimes feed a juvenile female displaced from Mandarte or another nearby island.

Nasty as it appears from a human perspective, displacing first-year females provides a vital boon to populations on small islands. The young female may appear next spring on a different little island and find a mate. She brings new genes. Research shows that inbreeding is a major hazard for isolated populations. Birds with a portion of immigrant blood are better by all measures. They even sing larger repertoires. The Mandarte Song sparrows would degenerate without a constant trickle of immigrant genes into the population.

It disturbs me to read about Song sparrow dominance, survival, aggression and territory. I see those themes in my own life and I don’t like them much. Last fall, chairing with the North Jubilee Neighbourhood Association felt to me like a territorial scrap, prolonged and exhausting. I perched and sang my repertoire about Bowker Creek, habitat rehabilitation and public greenspace. The struggle wore down my resilience and hopefulness and consumed too much of my attention. My practices of exercise, meditation and listening for birds mostly lapsed.

Walks with Fuller, the one-year-old, help me pay some attention to birds. The little guy, as I pushed him on the swing in Fern Street Park, said “Ooo” and pointed up at groups of cormorants crossing purposefully overhead. He said “Ooo” and pointed at the neighbour’s bamboo thicket where Golden-crowned sparrows sang more musically than the usual roosting gang of House sparrows. But mainly he just wants me to push the swing.

Song sparrow singing is beautiful and brutal at the same time. I think of Fuller. His baby play will develop, I suppose, into normally aggressive dominance play with other little boys. Vying for high rank in dominance hierarchies and for territory – the urge is intrinsic to Fuller, to me, to the human animal, same as to Song sparrows. But the human is a social animal. Fuller will manifest also, I trust, the normal human urge to fit and to serve in community, in collective entities beyond self and immediate family. We need that capacity right now on our tiny island.

One of the great photos from space is the Pale Blue Dot, Earth from six billion kilometers away. In 1990, theVoyager Onespace probe turned its camera back toward home just as we were vanishing in the distance. We see our planet as tiny and alone as, in Carl Sagan’s words, “a mote of dust suspended in a sunbeam”. If we view Mandarte Island as a small, isolated habitat, what is Earth? We observe the Mandarte Song sparrow solution to over-population and over-consumption in a small island ecosystem. How will we humans resolve ours? We now use up far more resources each year than our habitat can replenish. We degrade the planet’s ability to support us. Our population and consumption continue to increase. Like the sparrows, we face limits.

But we are not them. Their instincts prompt them only to fight for dominance and territory. Ours move us also to expand kinship, widen community and serve. We zoom-in the blue dot in space and observe an island population that is humankind, an island ecosystem that is Earth life. We extend it our concern and care.

 

 

13. Thryomanes Bewickii

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September 8, 2016

Fern Street is Bewick’s wren territory. With bravura, as long as I have lived here, males have sung in plain view on treetops. But I haven’t noticed. Thryomanes Bewickii has foraged underbrush, calling out harsh and sharp at the neighbour’s cat. How disconcerting to learn of the bird now. It cracks a self-image I would prefer to maintain, of knowing about nature in the city. Now I consult my books. Birds of Victoria and Vicinity uses capital letters: “THIS IS THE MOST COMMON back yard wren of Victoria.” I search online. Val Schaefer says: “Here in James Bay, Victoria, BC Canada, our ‘signature bird’ may be the Bewick’s Wren.” That’s the problem with old, cherished self-image; you have to keep it in a climate-controlled room. Let fresh air in and it crumbles to dust.

Listening early in the morning on the fire escape lets in fresh air. This week a bold bird voice came from Fern Street Park, from the trees across the field. That was awkward. It meant walking down the field beneath all the apartment and condominium balconies in pajamas and robe on dewy grass in wet slippers to peer with binoculars into someone’s back yard. A little bird sang strongly at the top of a fruit tree.

It sat upright, more like a flycatcher than a warbler, I thought. It sat and sat and sang and sang, giving me time to study. Its tail appeared longer than a warbler’s; its beak also longer, and curved. Wings looked plain and dark; under-parts plain and light. I noted a possible light eye-stripe. I looked-up flycatchers in my field guide and in a local checklist. A few flycatchers are common in Victoria; I listened on my phone to recordings of their songs. None really matched with the bird at the top of the fruit tree. It sat and sat and sang and sang. It cocked up its tail like a wren. I looked-up wrens in the field guide. Bewick’s wren! The songs in Bird Songs of Canada’s West Coast did not really match, but the narrator mentioned that “Bewick’s wren make a variety of perky songs and calls.”

“Variety” perhaps understates. The Birds of North America website reports that a male may sing more than twenty different songs from many high perches in its territory. He repeats each song more than twenty times before changing tune. A graduate student may follow the wren the entire morning to record all his songs. Nor are they exactly like his neighbours’. A young wren, first claiming a territory, learns to sing by imitating the males around him, but may err slightly in his copy. Next year’s young males will imitate his error. Dialects evolve, local and regional. Isolated populations develop distinctive dialects. The bird on the fruit tree probably sang in southeastern-Vancouver-Island-ese. Ocean isolates our Bewick’s wrens.

Crossings between distant islands would daunt our Thryomanes Bewickii. They don’t migrate. The Birds of British Columbia, Vol. 3 (1997) finds no evidence of Bewick’s wren migration in BC. They barely disperse. A study in Oregon showed juvenile males relocating only about one kilometer from home, staking a territory the same year, and defending it permanently. The territories covered only about two hectares (4-5 acres) of thick, shrubby vegetation. Even in sparse habitat, such as this urban neighbourhood, territories might cover only four hectares. The Oregon birds didn’t fly far. Their longest flight might cross a couple of acres, carrying bugs home to nestlings or chasing out an intruding wren. Most flights darted between patches of dense cover, less than twelve meters.

Its stay-at-home habits cause Bewick’s wren to evolve local races. Across the bird’s range from here to Mexico, science currently recognizes sixteen subspecies. Our Vancouver Island wrens belong to subspecies calophonus along with birds of western Washington and Oregon. It seems likely that Thryomanes Bewickii calophonus originally expanded here from Oregon and Washington during a time when warming climate was enlarging their habitat northward. The male that sang from the fruit tree across the park could probably claim ancient ancestry on Vancouver Island.

Its territory might include this entire city block. Aware now of Bewick’s wrens, I have noticed one singing in the front yard from the top of the holly tree and foraging low in the native plant area underbrush. The native plant thicket stacks-up not-badly as habitat. The heart of Thryomanes Bewickii country is dry scrub and chaparral of the US Southwest. Salish Sea coast provides the northwestern extreme of the species’ range. We have dry-enough summers, mild-enough winters and dense understory vegetation. We also have, in the words of the Atlas of the Breeding Birds of British Columbia, “anthropogenic landscapes,” shaped-by-people landscapes. Bewick’s wren has little problem with human presence in its territory. The Birds of British Columbia cites a study that found almost 80% of Bewick’s nests in back yards, on farms or in gardens. Almost half of the nests were in sheds, garages and barns. Nest sites included: “pockets or sleeves of clothing left hanging in abandoned buildings, garage drawers and cupboards left slightly ajar, behind a frying pan hanging on a post…[and inside] a paper bag half filled with nails.” As long as my gardening avoids neat-and-tidiness and allows insect abundance, Bewick’s wren welcomes me to its ancestral lands.

How ancestral? Little brown stay-at-home bird, when did you cross to this island from the mainland? How? Such questions allow fresh air gusting into my self-image vault in a swirl of plaster flakes. I have been happy with my picture of this hillside, valley and creek over the past 15,000 years: Glacier departs; land soon rises from the sea; creek flows down the valley; between 14,000 and 13,000 years ago life rushes in – salmon, willow, warbler, people in boats. I would prefer to maintain my illusion of knowing what I am talking about, but these bird questions make me consult people who know vastly more than I do. I went on a walk led by Grant Keddie.

Grant has served for decades as curator of archaeology at the BC Provincial Museum. Evenings and weekends, he has explored locally for hints of our deep history. He tells of recovering a bison tooth from the trench for a sewer line on Haultain Street. If I understand it correctly, Grant Keddie’s picture of this valley’s past includes a period around 12,000 years ago, dry and cold, of grasslands and of lodgepole pines in open forest, of bison herds (gigantic Bison antiquus, now extinct). The picture does not look to me like year-round habitat for Thryomanes Bewickii. I see landscape more like present-day northern BC, east of the Rockies. Winters here 12,000 year ago look too harsh for Bewick’s wren.

On this Fern Street hillside 12,000 years ago we probably hunted the bison and other large mammals. A backhoe on Orcas Island recently uncovered bones of Bison antiquus bearing marks of our stone cleavers and choppers. Orcas Island is only forty kilometers from here. Archeologists believe that hunters butchered the animal on the ice of a frozen pond approximately 13,500 years ago. Falling sea level in that era was converting enough seabed into dry land that the big animals could cross to Vancouver Island, maybe by 12,500 years ago. Their nomadic hunters would follow them. Did the buffalo hunters encounter any people already living here? How did we humans negotiate that meeting? I wonder.

I could not absorb all the information from the walk with Grant Keddie. I took home confusing scribbled notes and the impression of several big shifts in climate, vegetation, animal and human populations. He mentioned that he hopes to work with Richard Hebda, the Provincial Museum’s curator of botany and earth history, to write our local story since the most recent ice age. I need that article now.

New local discoveries about our distant past are emerging in this century, and particularly in this decade. In Bowker Valley it helps that we sit physically between the BC Provincial Museum and the University of Victoria. Scientists of various disciplines wonder and share information about this region where they live. Master of Science candidates select local topics for their thesis research – Kristen Rhea Miskelly, for example, Vegetation and climate history of the Fraser Glaciation on southeastern Vancouver Island, British Columbia, Canada (2012). Miskelly’s thesis proposes an ice-age refugium for plants and animals on southeastern Vancouver Island. Much land in the hills west of Victoria may have stayed both above water and free of ice throughout the Fraser Glaciation. Grant Keddie suspects increasingly that elk and other large mammals survived on the Island throughout the ice age. He hopes to prove it.

Searching for a truer picture of this hillside, valley and creek since ice departed and land rose from the sea, the most helpful article I have found is Richard Hebda’s Biodiversity: Geological History in British Columbia (2007). My impression from Hebda is that the dry, cold era of lodgepole pine open forest and grassland extended through the valley’s first 3,000 years – approximately from 14,500 to 11,500 years ago. Sudden, severe cooling ended the bison era about 11,400 years BP (Before Present). Deep winter freezing during five cold centuries broke down our grassland and pine forest ecosystems. Shrubby, stunted alder may have colonized. I wonder which large mammals remained in our valley. Which died out, moved out or moved in? Did people follow them? Certainly I don’t see Thryomanes Bewickii here during that cold period – but I see them arrive soon after.

Around 10, 900 years BP, climate turned warm and dry, with hotter summers than today. Extreme low sea levels continued to bare so much of the seabed among the Gulf and San Juan Islands that entire ecosystems could cross over to colonize Vancouver Island from the south. Habitat for Bewick’s wren expanded all around the Salish Sea. Douglas fir forest, with dense, shrubby understory spread into and beyond its present zone. Garry oak ecosystem established here also, and wildfire repeatedly cleared swaths of Garry oak meadow. Between 11,000 and 8,000 years ago approximately, this hillside and valley may have looked much like Oregon oak lands look today. The people likely hunted animals we know now on the Island, and possibly dug camas bulbs in meadow. During decades between wildfires, patches of dense brush would grow among the old oaks, and we probably heard Bewick’s wrens sing.

Climate turned slightly cooler and wetter from 8,000 to 4,500 years ago, increasingly like the present day. More Douglas fir forest moved into the valley. Redcedar forest established in damp soil along the creek. Wildfires decreased. Oak meadow zones shrank. People may have adjusted by purposely burning the underbrush to preserve meadow for camas-gathering and forest edge habitat for hunting. Sea level was rising. Shoreline gradually receded to its present position, with the creek mouth at Oak Bay. Ocean increasingly isolated Island plants and animals, including Bewick’s wren. From about 4,500 years BP, the valley and its people maintained generally the same ecosystems that enchanted fur traders landing in 107 BP (1843).

I feel better already. Acquiring this new information applies cement to the cracks in that old self-image. I hear Bewick’s wren sing this morning from the top of a spruce tree across Fern Street. What’s that you say, little bird? Your song tells me: “Forget this inward-looking self-image business. Sit up straight. Sing out. Stake life’s claim to this hillside and valley. Fight for us when you need to.”

2. Corvus caurinus

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June 18, 2016

Crows was the second sound I noticed this morning. The first was partiers returning home. Emma has the bedroom again, so Sherryll and I slept in the living room with a front window open. Lots of life happens on Fern Street’s only block. Hundreds of people live here in four-story apartment and condominium buildings, townhouses and a few old wooden houses, circa 1910. We live in one of those, the Friends Meeting House, mid-block. “Friends” comes from the proper name for Quakers, the Religious Society of Friends. As Resident Friend, Sherryll takes care of the building and the rentals to groups who meet here. Generally Fern Street remains decently quiet until six-thirty or seven, but the crows got noisy much earlier. Raspy, emphatic, this bird voice I recognize.

Everyone in Victoria knows crows. The term “in-your-face” comes to mind. On strike, many years ago at a school a few blocks from here, I paced round and round the block. Each time around, insulting crows dive-bombed my placard and me as I passed under a tree with a nest. Springtime always brings stories of hats knocked off or scalps scratched.

Our crow species on Vancouver Island is the Northwestern, Corvus caurinus. Or maybe not. New genetic studies may be changing the picture. Northwestern crow looks identical to American crow, just slightly smaller. My bird books assure me that American crow stays away from British Columbia’s coastal islands and keeps generally east of the Coast Range mountains. That belief might be wrong.

Corvus caurinus translates as “the crow of the northwest wind”. Its evolution as a separate species has occurred recently, within the last 400,000 years, during ice ages. Glacier has periodically advanced and retreated during that time period.  Sometimes it has burdened almost all of British Columbia, from the Rockies to the ocean. Only a few fragments of coastline have remained free of ice. In the most recent advance, for example, between 25,000 and 11,000 years ago, glacier covered the coast here at Victoria, but bits of ice-free seashore persisted at such spots as Naikoon Peninsula on the islands of Haida Gwaii, and likely on Vancouver Island’s Brooks Peninsula. Such places became refugia, where many animal and plant species survived. Crow populations likely persisted there, isolated for millennia, adapting and evolving into Corvus caurinus – shoreline foragers.

On the ebb tide they combed the beaches and rocks. Fish, living or dead, crabs and shellfish became their staple foods. They learned to dig clams, fly up and drop them on rocks to smash open. High tide forced the crows onto dry land to forage berries and bugs, and to eat seafood they had cached during low tide. When humans arrived, Northwestern crow learned to watch for edibles that we left unguarded.

British Columbia coastline has included human camps and villages for many thousand years. Some scientists argue for sixteen or seventeen thousand. People were moving south from Beringia, the land that linked Alaska and Siberia during the most recent ice age. In the coldest millennia, ocean levels lowered drastically because glaciers held much of the planet’s water. Huge areas of continental shelf dried out. Where the Bering Straits now separate Asia and North America, low sea level exposed a land corridor 1,500 kilometres wide. Extreme dry climate kept much of it free of glacier. Humans migrated there from Asia and survived its harsh tundra conditions. People from Beringia traveled south, populating our continent. Some came down the Pacific coast.

Did we migrate by land or by sea? Scientists have debated. If boats carried us, then we may have arrived as long ago as 17,000 years, and settled the coastal refugia. Evidence would be hard to find, however. More than a hundred metres of water now submerges those shores where we and the Northwestern crow may have dug clams. Certainly “the crow of the northwest wind” has long since learned to scout for edibles that people might leave unwanted or unattended. Stealing our sandwich from the picnic table and rummaging our village midden are ancient high-tide behaviours.

As the planet warmed and glaciers retreated, Northwestern crows from the refugia could extend their range north and south along the shore. They would meet American crows that were moving up from the south and would interbreed. Recent genetic studies suggest a long coastal zone where Northwestern and American crow genes have been mixing completely. Victoria might be sitting in the middle of that zone. Pure Northwestern crow genes may persist along the Alaska coast, and pure American crow genes on the California coast, but our population on Vancouver Island appears share both ancestries. What should we call them?

I have wondered when crows first arrived in Victoria. Here at the Quaker Meeting House on Fern Street, when did crows first converse? In Victoria the glacier that covered us in the recent ice age was gone around 15,000 years ago. We were under water though.

The weight of the ice had depressed our bedrock possibly two hundred metres. It takes some imagining. The rock that outcrops in the Meeting House front yard would not easily squish down, one would think. To make sense of it, I remind myself that this rock may be solid, but it’s not so thick. Our bedrock is a thin skin on the planet, maybe ten or twenty kilometres deep. The next layer down is more plastic, semi-molten. Our bedrock floats upon it.

Floating brought Vancouver Island here. Our journey began south of the equator 300 million years ago. Volcanoes under the ocean built islands and archipelagos. The plate of bedrock of which they were part drifted north, slowly. The islands collided with North America 100 million years ago along the Oregon shore. Then, in the slowest of slow-motion shipwrecks, they bumped and scraped north along the coast, leaving bits behind. Vancouver Island was one piece of the wreckage. The Islands of Haida Gwaii, another. The final pile-up added mountains to southeast Alaska.

So yes, I can imagine that glacier depressed this floating bedrock. When the ice went away, Victoria’s downtown lay maybe seventy-five metres submerged, but Fern Street is higher than downtown. Probably forty or fifty metres of water covered our block. When did Fern Street emerge from the sea?

Our bedrock, free of glacier burden, rebounded upward. Sea level was also rising as continental ice continued to melt. In the vertical race between our bedrock and the ocean, we moved faster. Sometime between 15,000 and 14,000 years ago, Fern Street pulled out above the water. We sat on the shore of a small island, looking out across sea surface and other little islands. Crows no doubt foraged at low tide, digging clams in the sand. Did the crows see people? I doubt it. The little rocky island might not yet offer much to attract humans.

Further downhill from the Meeting House, shallow water still covered flat seabed. Land continued to rise. Around 13,500 years ago, our valley fully emerged. A stream picked its path in glacial silt down the valley bottom. These days we call it Bowker Creek. Salmon found it as soon as the ice departed, I suspect.

When glaciers melt, salmon quickly populate the new streams. Scientists observe at Glacier Bay, Alaska, where retreating ice exposes new shoreline every year. A new creek appears. Within a decade, salmon are spawning and crows are picking at carcasses. Life rushes in. Fifty years along, willow and alder grow dense on the streambank; songbirds nest; thousands of salmon crowd the creek mouth.

How about people? When did we find Bowker Valley and this Fern Street hillside? Archaeology has exposed a village site near the mouth of the creek at Oak Bay. It dates back less than 3,000 years, but for sure we have lived here much longer. A salmon stream has meandered several thousand years down a gently-sloping valley to a shore abundant in seafood. People are as observant and opportunistic as crows; we recognize food sources when we see them. Hard evidence is not available though. Our most ancient camps and villages at the creek mouth would now be difficult to locate.

“When and how did people arrive here?” – the question has always challenged Archaeologists on the British Columbia coast. My first wife, Marjorie, worked in the 1970s at digs, which I visited. It surprised me that they uncovered coastal villages far from the coast, riverside camps far from the river. Figuring out when shore was where is so complicated here. So many factors play. Glaciers depress bedrock, then melt; rock rebounds and ocean rises; rivers dig channels and build deltas; floating plates of bedrock drift, collide, shove persistently together, buckle, heave mountain up and trench down. British Columbia shoreline does not stay put.

In the present decade, science has given us a clearer picture of shoreline movements since ice-age glaciers melted. A journal article open now on my computer is Post-glacial sea-level change along the Pacific coast of North America by Dan H. Shugar et. al., from Quaternary Science Reviews online, 2014. Isn’t this a time? Sitting in pajamas at the Meeting House kitchen table with a cup of tea, one can search out information on local sea levels in ancient days. Reading the paragraph about Victoria and looking at the graph, I see Bowker Valley hoist fully out of the sea maybe 13,500 years ago, and continue slowly to rise. Shoreline continues to move down across Oak Bay seabed and beyond, perhaps forty metres below present sea-level. Then, around 11,000 years ago I see water-level rising. The shore gradually moves back inland to its present position a few thousand years ago.

So those first humans who landed our boats at the mouth of Bowker Creek and camped here: where should we look for the campsite? If we arrived before 13.5 thousand years ago, the creek mouth would be somewhere upstream from today’s shoreline. Maybe we camped under the parking lot at Hillside Mall. If we arrived between thirteen thousand and five thousand years ago, our first campfire might now lie somewhere beneath the waters of Oak Bay or Baynes Channel. From generation to generation we likely relocated our camps or villages repeatedly back from the shore as rising water inundated them. Money for Archaeology is scarce. We may never find more ancient camps in Bowker Valley.

Why would I care? What does it matter when Fern Street rose from the sea, or crows arrived, or people? Why would the shifting picture of our restless shoreline delight me? Why, indeed, would Shugar et. al. devote all that research time, brainpower, grant-application effort, love, to pin down Post-glacial sea-level change along the Pacific coast of North America? Partly, they were looking for places to dig holes. It comes back to the question of when and how humans first populated the Pacific coast – where to look for our first villages on shoreline that keeps changing.

The researchers identified a segment of British Columbia shore that stayed put when the glaciers departed, coastline where the various forces, pushing land and sea up and down, all balanced. Archaeologists dug on the shore of Calvert Island, halfway up the BC coast. Humankind dug, I would argue. Forensic human brain delved rectangular pits at the shoreline. Our species has evolved gathered around tracks in the mud, interpreting their story. It keeps us alive. Is food nearby? Is danger? Digging on the beach at Calvert Island, we found, one metre down, a footprint in the clay. Further pits uncovered footprints of three people, a family group around a hearth fire with a stone knife for cutting food. Carbon dating indicates antiquity of more than 13,000 years, the oldest human footprints yet found in North America.

More digging, on Triquet Island nearby, has moved the record of humans on BC’s central coast back further, to 14,000 years ago. It shows that people in boats were quickly populating the shore as the glaciers pulled back.

The pits at Calvert and Triquet Islands: I want to say that Earth dug them. The planet evolves capacity, I want to say, delicately to apply trowel and whisk broom to its own skin. Earth wonders who and what she is. The guy at the Fern Street kitchen table is just a moment of conscious attention Earth applies to her question. He reports: I hear people in Bowker Creek’s valley coming uphill. This is sometime between 13 and 13.5 thousand years ago. I am likely wrong. This is a family from the camp at the mouth of the creek. They explore, hunt, forage today upstream and up this hillside. A crow in the valley watches them and comments. A crow here answers.