Natural Calendar of the Lake: a lacustrine phenology

Herein lies a natural calendar for Kootenay Lake. There is variability in the times of natural events. Further, at this early stage in the construction of the calendar, some of these times are rather speculative. Most of the material here about local birds is provided by Janice Arndt.

Here is the contact to offer improved times and content for this calendar.

The Earth is closest to the Sun (its perihelion) in the first week of January. It is about 2% closer than the average distance and 4% closer than the greatest distance which occurs in the first week of July. (The seasons, of course, result from the Earth’s axial tilt to the orbital plane, not its distance).

The Lake level begins dropping.

The West Arm hosts a diversity of waterfowl during the winter months. January is a good time to become familiar with duck identification as most species have finished moulting into their alternate, or breeding, plumage, and the males are more easily recognizable. The following species of waterfowl are present each year on Kootenay Lake: Canada Goose, American Wigeon, Mallard, Ring-necked Duck, Greater Scaup, Lesser Scaup, Bufflehead, Common Goldeneye, Barrow’s Goldeneye, Hooded Merganser and Common Merganser. Others occur in smaller numbers or are not present every year, including Gadwall, Canvasback, Redhead and Red-breasted Merganser. All of the preceding species belong to the waterfowl family (ducks, geese and swans). Other waterbirds that can be seen here in winter may be confused with ducks but are not officially classified as waterfowl; these include Common Loon, American Coot, Western Grebe, Horned Grebe, Red-necked Grebe and Pied-billed Grebe.

Birds to watch for on land in January include the small finches—siskins, redpolls and goldfinches. Pine Siskins are widespread and abundant in most years, although some years (2005-06) they are virtually absent. Common Redpolls are one of the so-called irruptive species, invading our region from the north in high numbers some winters and not showing up at all in others. Movements are determined by fluctuations in the availability of their natural food sources. American Goldfinches occur year-round in the Kootenays and may be observed in winter. Although they have different movement patterns, all three of these species are very closely related. They are all seed eaters and sometimes visit feeders stocked with black-oil sunflower seeds or nyger (thistle) seeds.

The Lake level continues down.

In years when Bohemian Waxwings spend the winter along Kootenay Lake’s shores, numbers often peak in February, with flocks sometimes numbering several thousands.

Relative to other regions of Canada, first signs of spring come early to southern B.C. Although few, if any, migrants are returning at this time, resident birds begin to give indications that the breeding season is approaching. Song Sparrows, American Robins, Varied Thrushes, Winter Wrens and House Finches may be heard singing. (A few, such as Black-capped Chickadees and American Dippers, sing year-round). Pairs of Canada Geese start hanging out on pilings, Osprey platforms and similarly elevated structures where they may eventually nest. By the end of the month, Black-capped Chickadees and Bald Eagles are showing serious breeding behaviour. The chickadees may begin excavating nest cavities in trees and snags, while the eagles add new sticks to their existing nests and demonstrate courtship and mating activity.

Spring equinox about March 21st. The day and night are both twelve hours long.

The Lake generally reaches its lowest level sometime late in March or the first half of April. Typically, the minimum (at Queen’s Bay) is about 530 meters (above sea level). This is about 2.5 m below the typical flood level and about 1.5 m below a characteristic summer level. Low water presents an ideal occasion for long walks along portions of the lakeshore which may be too obstructed by rocks or vegetation at other times of the year. This is also the time to see features hidden when the water is higher, features such as the remains of the old steam-powered days: some old landings and wharfs with their pilings cut short, and even ship wrecks such as the Kuskanook and the Hosmer. One can also see the mud and silt which is often deposited beyond the sandy portion of a beach. While the presence of this mud is interesting on its own account, certainly a bonus is the extent to which at low water it readily reveals the tracks of many animals: birds of various kinds, deer, and even beaver.

In March we begin to lose some of our winter avian visitors. The flocks of American Coots and Greater Scaup that overwintered along Nelson’s waterfront often disperse by mid-month, while Bohemian Waxwings will leave the area by the end of the month.

There are several corresponding arrivals of species that have been absent through the winter months, including Killdeer, Violet-green Swallows and Spotted Towhees. Other species such as American Robins and Dark-eyed Juncos have been present in small numbers but their ranks swell considerably and they become more active and vocal, making them much more conspicuous. Resident Red-shafted Flickers and Merlins also become rather noisy and are even considered to be a nuisance by some who live within the territory of one of these birds

The approaching Spring is also revealed in the number of singers on mild days. For people wishing to learn to bird by ear, March is a good time to start as there is enough variety to be interesting, but not so much as to be overwhelming. In April and May dozens more species will be adding their voices. The following birds may be heard singing in March: Varied Thrush, American Robin, Townsend’s Solitaire, Winter Wren, Golden-crowned Kinglet, Brown Creeper, Black-capped Chickadee, European Starling, Song Sparrow, Dark-eyed Junco, Spotted Towhee, House Finch and Pine Siskin. Their songs are diverse in both structure and volume, ranging from the quiet songs of the kinglet and creeper, the simple two-note song of the chickadee, and the muted, haunting call of the Varied Thrush, to the exuberant outbursts of the Song Sparrow and Winter Wren.

Tundra Swans visit the Lake during their migration north.

By the end of the month, Bald Eagles and Canada Geese have already laid eggs, and a few individuals of some other early breeders, including chickadees, nuthatches, robins and jays may begin building nests.

The Lake generally reaches its lowest level late in March or during the first half of April. Read the discussion under March about things to see. By the last week of April the Spring freshet has begun and the Lake begins its rapid rise to flood levels which are generally reached in late May, early June.

Thermal stratification begins in the South Arm. This stratification will increase for many months with surface temperatures reaching 20°C in the summer, although at depths of 50m the temperature remains around 4 to 5°C. The North Arm remains colder and does not begin to stratify until mid July.

The skiing season at the local resorts (Whitewater, Baldface) comes to an end early to mid April.

April brings many arrivals of birds that have wintered in milder regions. Early in the month, we can expect the first Ospreys to return. The earliest individuals of this species are usually males and they soon settle onto their territories from previous years. Ruby-crowned kinglets often begin to pass through our area in the first week of April. They are little birds with big songs. Yellow-rumped Warblers are the first of their clan to return to the Kootenays, followed by Nashville, Orange-crowned and Townsend’s Warblers later in the month. Other arrivals in April include Red-naped Sapsuckers, Cassin’s Vireos and various species of swallows (Tree, Cliff and Northern Rough-winged) and sparrows (Savannah, White-crowned and others). Mountain Bluebirds and Wood Ducks are not common here at any time, but these striking species can sometimes be seen along the West Arm in April.

Many people—birders and non-birders alike—watch for the return of the first hummingbirds each spring. We have three lovely species: Rufous, Calliope and Black-chinned. Rufous Hummingbirds are relatively large and aggressive, and individuals may dominate a good feeding area. The Calliope is North America’s smallest bird. The Black-chinned Hummingbird is by far the least common of the three here, but reports of this bird appear to be increasing. Females of these species are very difficult to identify, but males can be distinguished provided they stay in one place long enough to give the observer a good look! The two common species, Rufous and Calliope, regularly return to Kootenay Lake during the last week of April. Placement of hummingbird feeders can begin anytime in the last half of the month. A mixture of one part white sugar to four parts water (by volume) is recommended. Please don’t use red food colouring.

Although they are sometimes heard in summer and fall, the peak drumming period for Ruffed Grouse is in April and May. The drumming sound isn’t made from the wings hitting the bird’s body or perch, but from the vacuum created by the wings beating the air. Robins, crows, ravens, juncos, killdeer, eagles and geese and others are on nests. In the last week of the month the first goslings will appear. Though there is already a lot of activity here in April, many of our long-distant migrants are still en route from their Central and South America wintering grounds!

While the female robin is busy nest building, the male defends territory. Alas, it often defends it against its own reflection in the window: repeatedly attacking what apparently is perceived as a remarkably persistent and vigourous intruder. This window bashing can carry on all day at a frequency of one every three or four seconds. Sigh, it might not let up until chicks hatch and the male becomes preoccupied with feeding them.

Buds appear on deciduous trees early in the month and blooms late in the month.

Gerrard Rainbow Trout spawning.

Snow is at its maximum depth on the highest mountains.

May has the greatest concentration of returning songbirds of any month of the year. While a few will have arrived already in April, the great majority of insect-eating species return in May, including many flycatchers, vireos, thrushes and warblers. Gray Catbirds, Cedar Waxwings, Western Tanagers, Black-headed Grosbeaks, Lazuli Buntings and Bullock’s Orioles also return to our region for the breeding season. Songbirds passing through to more northern regions (or higher elevations) include American Pipits, and Lincoln’s and White-crowned Sparrows.

Blue-winged, Cinnamon and Green-winged teal, as well as Northern Shovelers may be seen at this time of year. Most Western Grebes, Buffleheads and American Wigeon leave the West Arm during May and will not return until the autumn months. Spotted Sandpipers return to nest along our shores. Careful observers may find an occasional Wilson’s Phalarope or Solitary Sandpiper passing through.

Many birds that either over-wintered or returned earlier in spring, are already incubating eggs or tending young. [These include Canada Geese, Mallards, Bald Eagles, Ospreys, Red-tailed Hawks, Killdeer, Northern Flickers, American Crows, Common Ravens, Black-capped Chickadees, Red-breasted Nuthatches, American Robins, Song Sparrows, Dark-eyed Juncos and Pine Siskins.]

Summer solstice about June 21st. The day is about sixteen hours, the night about eight hours long. So, at our latitude, the summer solstice brings twice as much daylight (16 hours) as does the winter solstice (8 hours).

The Lake reaches its maximum flood level and begins to fall. Typically, the maximum elevation of the Lake’s surface (at Queen’s Bay) is about 532.5 m (above sea level). This is about 2.5 m above the lowest level and about a meter above a typical summer level.

In terms of comings and goings and the potential for seeing new species, June is the quietest month. There are virtually no bird species moving north, south, upslope or downslope. However, all the birds here are buzzing with activity as every one is at some stage of its breeding cycle, whether defending a new territory, building a nest, incubating, feeding flightless chicks or caring for fledglings. Even the earliest-hatching young, including Canada Geese, are still in the company of their parents. A few early-nesting songbirds, such as Song Sparrows and American Robins, are capable of raising more than one family in a season because of their relatively short nesting cycles. The males of most duck species appear to be resting during the early summer while the hens care for their broods; however, even though they are no longer occupied with breeding activity, they are undergoing a moult to renew their alternate (breeding) plumage, which also requires considerable energy.

The Earth is farthest from the Sun (its aphelion) in the first week of July. It is about 2% farther than the average distance and 4% farther than the least distance, which occurs in the first week of January. (The seasons, of course, result from the Earth’s axial tilt to the orbital plane, not its distance).

Snow has melted on the higher mountains

Thermal stratification begins in the North Arm in mid July.

The Lake level stabilizes at its summer levels.

During the first half of July, most songbirds are still busy with breeding activities, as described, above, for June. Some individuals of each species are still tied to the nest site, tending to eggs or nestlings, while many have young already out of the nest. In the latter case, the families remain together for one to three weeks, but are free to range more widely, as it is very rare for the young to return to the nest, even at night. Birdsong generally decreases during this time.

At this time of year, it is not uncommon to observe young cowbirds being cared for by their substitute parents—the adults caring for them are never cowbirds. Cowbirds are brood parasites, a term used to describe species that lay their eggs in nests of other birds. They never build their own nests. Brown-headed Cowbirds are the only brood parasites in B.C. The female cowbird lays an egg in another bird’s nest among that bird’s own eggs. The foreign egg is then incubated by the owner (or host) of the nest, and when hatched, the young cowbird is fed alongside the host’s young. Sometimes the cowbird outcompetes the rightful young for food, either because the cowbird hatches first, or because the cowbird is bigger than the host’s young. Hosts are often smaller birds like warblers and vireos. Amazingly, the host pair can sometimes manage to meet the demands of both the cowbird and its own young, and all survive. Common cowbird hosts include Yellow Warblers, Warbling Vireos and Western Tanagers. Later, when the young cowbirds are independent, they can become very tame, to the point of hopping around the feet of picnickers and sunbathers. At this stage, a young cowbird resembles a large sparrow.

Other sights to watch for in July are broods of Common Merganser ducklings, following their mother in the water, hitching a ride on her back, or lazing around on a rock or beach. Broods can be large: 10 is not uncommon and up to 16 young have been seen in one family. Most Bald Eagle young leave their nests by the middle of the month. Their plumage is all-dark at this point and they are essentially full-size, making it easy to mistake them for Golden Eagles. Numbers of Great Blue Herons and gulls increase in July, as both adults and juveniles disperse to the West Arm from breeding colonies outside our area.

Huckleberry season.

The Perseid meteor shower reaches its peak activity about August 12th. If it is clear (as it often is at this time of year), find a place where you can watch the whole sky by lying on your back on (a blanket) on the ground. The meteors which streak across the sky will all seem to have originated in (flow radially out of) the Perseid constellation.

Kokanee (Red Fish) are spawning from late August through September.

Breeding activity is winding down for most birds in August. Cedar Waxwings are among the latest-nesting songbirds; few others are incubating eggs this late. Most Osprey young remain in their nests until August, although some from early nests will have started flying in late July, and others may not fly until the first week in September.

Evidence of migration begins to mount. Warblers, vireos, flycatchers and others may start flocking and foraging in mixed-species groups. Swallows may form flocks of several hundreds. Shorebirds from northern areas have already started south and small numbers may sometimes be found on suitable mudflats in the area, including Kokanee Creek Provincial Park. However, the presence and precise location of good habitat is unpredictable due to water level fluctuations. A few hummingbirds remain through August, though adult males have generally been absent for several weeks already.

Fall equinox about September 21st. The day and night are both twelve hours long.

Migration is fully underway for most birds that are not residents. The majority of the smaller insect-eating songbirds, including swallows, warblers and flycatchers will be gone by mid-month. Passage of raptors and sparrows through the area peaks in September then continues into October. Sparrows to watch for include White-crowned, Savannah, and Lincoln’s; these species are much more common during migration than at other times of year. Now is a good time to set up a feeding station with sunflower seeds and white millet.

Male mallards are looking strange in their stages of moult due to the varying patterns of green and brown feathers on their heads. Ospreys, eagles, ravens, gulls and others congregate at the mouths of creeks that host spawning kokanee.

Cedar Bugs begin to seek shelter in the warmth of homes.

While most migratory songbirds have left the area by this time, numbers of waterbirds begin to swell in October. Western, Horned and Red-necked Grebes continue to move in, as do Ring-necked Ducks. Buffleheads and Greater Scaup arrive from northern regions. Common Loons, Mallards, and Common and Hooded mergansers are present throughout most of the year, but may be undergoing changes in their appearance. Each species is on its own moult schedule: some loons are still in their breeding (or, alternate) plumage which they have retained through the summer; most male Mallards and Hooded Mergansers have already exchanged their dull non-breeding (or, basic) plumage of summer and early fall for the bolder colours they will wear for the next nine months, but male Common Mergansers will continue to resemble females for several weeks longer.

A very few Ospreys linger around the Lake into the first few days of the month, but once they are gone it will be nearly six months until we see this species here again. Occasionally in October, Bonaparte’s Gulls can be observed migrating down the West Arm in flocks of up to eighty birds each. Several hundred gulls may pass through in one day.

The leaves of deciduous trees in the valleys and along the sides of the mountains turn yellowish, or in the case of the larch, orangish.

Snow begins to accumulate on the higher mountains.

The surface of the Lake has now cooled to the point that the summer stratification has ended. Now mixing can occur through the full depth of the Lake. The Lake will continue to be well mixed in the vertical until springtime warming brings stratification back in April in the South Arm and July in the North Arm.

By November, virtually all migrant insectivorous songbirds are gone from our region. Flying insects are few in number or absent entirely. Those songbirds that remain are the ones that can survive on a diet of seeds, berries or dormant insects.

Birds that fly south are replaced in part by new species from northern areas. These include various finches, such as Common Redpolls, as well as Bohemian Waxwings. Numbers of these birds vary from year to year depending on food supplies; they may be present in winter in flocks of dozens or hundreds - or in the case of the waxwings, even thousands - or they may not show up at all in some years. Other songbirds, like Mountain Chickadees and Pine Grosbeaks, make altitudinal migrations, nesting at higher elevations and descending to the valley bottoms in late fall.

Waterfowl numbers continue to grow. Look for increasing numbers of Buffleheads, Common and Barrow’s goldeneyes, and Greater Scaup. November through January is a good time to look for an occasional Redhead or Canvasback, particularly along the waterfront in Nelson. Common Mergansers are present here year-round, but take a look for males in their fresh breeding plumage; their moult occurs later than most of our other common duck species.

Some bird species exhibit leap frog migration, where northern populations migrate farther south than mid-latitude populations. This seems to be the case with both our Bald Eagles and our Canada Geese. These birds can be reliably found in their regular haunts along the West Arm at this time of year, while others of their species are seen migrating overhead. Geese may be observed flying high in characteristic V formation, in numbers of up to 150 or more, migrating south-west along the West Arm; individual eagles appear to follow the same route.

Also migrating along the West Arm in November are small numbers of Tundra Swans. Occasionally they will touch down for a time; Kokanee Creek Provincial Park is the best place to look for these birds.

Winter solstice about December 21st. The day is about eight hours, the night about sixteen hours long.

The early snows of December (and late November) provide a superb opportunity to see the tracks left by animals. Often the passage of a nocturnal animal goes unnoticed, but now the movement of everything from a bear to a deer mouse is suddenly visible.

Bird species composition changes little from November to December, with only local movements occurring among individuals or flocks. Sightings of some birds, such as Northern Pygmy-Owl, Gadwall and Townsend’s Solitaire may increase this month. Flock sizes of goldeneyes, scaup, waxwings and finches may increase in specific areas as birds congregate at productive feeding areas. On snowy days, robins can be seen in flights along the lakeshore, possible as a response to temporary changes in food availability. Rock Pigeons (Doves) are the only local birds known to continue nesting throughout the month of December.

The skiing season begins at the local mountain resorts (Whitewater, Baldface) early to mid December.

Events which have been suggested for inclusion, if an approximate time can be found:
wood tick season, safe removal of a wasp nest, snow disappears from Elephant Mountain, oregon grape blooms and harvesting of berries.

Fraser tartan