12. Setophaga petechia

Autumn leaves on groundLQ

August 20, 2016

Our neighbours enjoy the Lombardy poplars. They grow tall along the back yard’s north fence. But they need more water in summer than this dry hillside naturally provides. Seeking moisture they send their roots invading the vegetable beds, berries and flowers. They stand out of place and time. They belong in the valley bottom along a ditch on a farm a century ago. A few old Lombardy poplars still do stand there, in fact, beside Bowker Creek.

Nostalgia moved Sherryll to plant Lombardy poplars at the Meeting House. She remembered evening light on lofty windbreak trees across a field; she pictured a high leafy backdrop for Quaker garden parties and family back yard picnics. The poplars do provide it, but Swedish columnar aspens, we belatedly learn, might offer the same benefits, more drought tolerance and less invasive roots.

On the Lombardy poplars, a few leaves are turning colour as fall approaches. No breeze blew this morning, but one yellow leaf detached and fluttered sideways into the next tree. Apparent defiance of gravity by a leaf merited a closer look. Binoculars revealed a yellow bird foraging with a thin bill for insects. A warbler.

Wilson’s or Yellow warbler? I won’t claim certainty. The checklist from Victoria Natural History Society shows both species common in August. Poring over descriptions and illustrations in Peterson’s Field Guide inclines me to identify the bird as a female or immature Yellow warbler, Setophaga petechia.

This was the most cheerful-coloured bird I have seen at Fern Street. Probably it was fueling-up on its way south. BC coastal geography funnels many migrant birds through the southern tip of the Island. The Rocky Point Bird Observatory reports peak numbers of Yellow warbler passing through in the last two weeks of August. I’m happy to think that our trees at the Meeting House may provide insects to power songbird migrations. Visits from little beautiful birds persuade me that bugs may be the garden’s best crop, though caterpillars attacking our fruit trees often challenge that viewpoint.

Setophaga petechia migrates far. In winter, from Mexico south into Peru and Brazil, it brightens-up tropical jungle, mangrove swamp and city park. In summer Yellow warblers fan out through temperate and arctic North America. For any Canadian who knows where to look, they adorn this nation from sea to sea to sea.

Where should we look? The short response is: patches of shrubby willow. Birds of British Columbia, Volume 4 (2007) reports:

“The Yellow Warbler breeds in sunlit stands of deciduous vegetation and has a strong attraction to willow. …. In general it prefers shorter trees in dense stands, and shrubbery in riparian habitats along stream courses, on the margins of beaver ponds, [and] wet meadows….”

“Riparian” –  the transitional zone between land and water ecosystems – the term appears often in descriptions of Yellow warbler habitat. It includes the shrubby edges of marshland and the banks of pond and stream. Locally The Naturalist’s Guide to the Victoria Region directs us to the riparian zone at Blenkinsop Lake where “…thick growth of willows and dogwood along the trail conceals Yellow warblers.…”

We grow no willows, genus Salix, in this yard or park. Local native willows would not naturally thrive on the dry hillside. They would prosper more on the flats along Bowker Creek. More broadly defined however, willows do grow in this yard and park. The larger willow family, Salicaceae, includes poplar, alder, birch and aspen. Our Lombardy poplars belong to it, as do the black cottonwood and white birch. We qualify marginally as habitat for Setophaga petechia, if only as a feeding stop for migrants.

Yellow warblers have illumined Bowker Valley, I expect, longer than people have been here to delight in them. Willows would establish quickly after the most recent Ice Age, and warblers follow. Observations of receding glaciers in coastal Alaska illustrate the pattern. Retreating ice leaves bare land, and willows take root within a few years. Within decades, warbler song and colour enlivens dense willow thicket.

When favoured habitat appears, Setophaga petechia quickly colonizes. “Yellow warblers are an indicator species,” the Atlas of the Breeding Birds of British Columbia states, “one guide to the changing landscape of British Columbia, and may be one of the first to expand into early successional habitats.” When logging removes coniferous forest, for example, alders spring up in the clearings and Yellow warblers move in. When we drain wetlands or clear willow from streambanks, warbler numbers decrease.

Bowker Valley offered Yellow warblers far more nesting habitat in the past than at present. Several kilometres of the creek and its tributaries meandered through marsh and ponds. The back cover of the Bowker Creek Blueprint document is a map from 1854. It shows many hectares of wetlands along the stream and its tributaries. Roughly estimated, wet areas on the 1854 map extended about six kilometers and averaged more than 100 metres wide (around 60 hectares or 150 acres). As at Blenkinsop Lake today, shrub willow and red-osier dogwood thicket would naturally occupy that corridor. Every May and June hundreds of Yellow warblers likely nested.

In 1854 the farming era here had hardly begun. Victoria’s settler population consisted mainly in fur trade employees at the Hudson’s Bay Company fort by the harbour. The map indicates that our valley’s only public road was a cart track across it (now Fort Street), connecting Fort Victoria to the HBC farm at Cadboro Bay. A side road branched off to a cluster of buildings on bottomland below this Fern Street hillside. They stood at present-day Carrick Street in the North Jubilee neighbourhood, and served Bowker Valley’s first farm.

The farm lot, labeled “Sec. 26” on the map, appears to include Fern Street and all of North Jubilee. Archival records indicate Modeste Demers as its holder. Marshy Bowker Creek meanders diagonally across it. Bishop Demers faced big challenges in 1854. The church had weighted its newly-arrived prelate of its newly-created diocese of Vancouver Island with responsibility for spiritual care of peoples of the entire BC mainland, its coastal islands and Alaska, but had supplied virtually no funding. Of his two priests, he had sent one up-Island to Nanaimo, and the other to the mainland. I would be interested to learn why he took up a land grant from the Hudson’s Bay Company and broke the soil of Bowker Valley. Did he personally wield the plough? Modeste Demers came from a family that had farmed in Quebec for two centuries. I imagine the middle-aged farmer clearing trees and brush and spading his potato patch.

The image disturbs me. Bishop Demers, did you dig your stretch of Bowker Creek straighter and deeper, drain your bit of its wetlands, cut and uproot your portion of its riparian willow thicket? Did the story of its degradation start with you? I continue your story. I break Bowker Valley soil again every year to grow potatoes; I dwell in comfort on your farm’s hillside pasture with hundreds of other people in huge buildings. Our roofs and roads prevent rain from soaking into earth; we divert stormwater churning down drains to our big storm sewer, the creek.

How may I reconcile my feelings of kinship, admiration, gratitude, disgust, anger and mortification? I dreamt of dead deer lying rotting in dewy morning meadow; maybe a hunter’s dump; it stinks; severed heads of sea lions stare as new lovers walk naked from last night’s embrace in the treetops, ashamed to awaken here. The girl touches her abdomen, aware of a new life. No going back now. The law, attraction, calls forth experience from innocence, summons new innocence out of old experience, spirals mind expanding always out through time.

Settlers: Modeste Demers, faithful servant of his church, missionary to the peoples who already lived here; James Douglas, fur trader, faithful servant of his company and empire. They were good friends, men of goodwill, decent proponents of their civilization’s ideals. Douglas had purchased the lands around Fort Victoria in 1850, including this valley, from the native families who lived in the area. Those families had chosen to live beside the fort. It offered profitable employment as well as safety from raids by more warlike peoples up-Island and up-coast. Potato patches provided starch with much less effort than did camas meadows. Fabric from the trading post provided clothing more conveniently than did wool dogs and spindles. Agrarian, industrial, global economy offered them an easier life. Who turns down that offer?

We sleep. We awaken many decades later in the city that Douglas imagined, in the valley that Demers’ shovel pierced, and walk down the hillside. Death stinks in the meadow: carcasses from fur trade slaughter, settlement and progress. Morning gifts us with new eyes and with guilt. Rest your palm on your abdomen; experience the new sense of justice that makes us feel sick here this morning. We are not who we were.

We carry a civilization to which we may give birth. The sense of justice we feel beneath our palm extends to every human, every species and ecosystem. Rest your palm on your abdomen; the civilization of one living Earth gestates. The law, attraction, calls us to bear and to serve it.

After 1854 change came fast in the valley. Farmers ditched and drained. A 1901 panoramic photo, snapped from Mt. Tolmie, shows pleasant farmland, no sign of shrubby marsh. Only in winter did the valley bottom stay soggy. A man I met remembered skating on the winter lake that covered the intersection of Shelbourne Street and Cedar Hill Crossroad. A woman who had lived upstairs from her family’s store as a child on Haultain Street told me of water inundating the shop. The residence upstairs remained dry and a rowboat ferried the little girl to higher ground for school.

Stormwater drains slowly in a low-gradient stream. Over its eight-kilometre length, Bowker Creek descends only fifty metres; slope averages about 0.6%. Crossing land at hardly any slope, a stream dawdles. It meanders and spreads into wetlands. In rainy winter it pools and stays flooded for months. Salmon and trout prosper.

Around the Salish Sea, streams like Bowker Creek were the most productive of Coho salmon. Coho juveniles live a full year in fresh water before migrating to the ocean. In winter, Bowker Valley marsh and swamp provided safe habitat in calm water. In the leafy seasons, shrub willow hid the stream, protected little salmon and trout from kingfishers and herons. Its cool water, shaded by willow, held abundant oxygen for fish to breathe. Shrubby riparian thicket also showered insects onto the stream surface for fish to eat. And it supplied insects for great numbers of nesting and migrating birds, such as Yellow warblers.

Gently sloping valleys also invite agriculture and city-building. City replaced farm in Bowker Valley during the Twentieth Century. Householders demanded dry ground all year. The creek became a stormwater-management problem for municipal engineers. They ditched it progressively deeper and straighter, then culverted most of it underground. Of Bowker Creek’s wide wetlands the last vestige persists at the University of Victoria, at the creek’s headwaters. Mature cottonwoods dominate swampy ground between the University Club and Gordon Head Road.

City engineers these days know that marsh absorbs stormwater, cleans it and prevents flooding downstream. Climate change appears to be giving us bigger winter rains. To mitigate flooding, Bowker Creek Blueprint recommends opening-up sections of the stream that now lie deep in culvert. As opportunities arise, we may engineer wetlands and meandering channel to slow and absorb high flows. On the old Demers farm in the Twenty-first Century, yellow songbirds aplenty may nest in riparian willow thicket at the city’s heart. Justice invites them.