Spring Black Swift Flocks

Another feature of North Okanagan birding is the regular occurrence of flocks of Black Swifts over Swan Lake, north of Vernon, from about the middle of May through early June. Elsewhere in the Okanagan Valley, things are pretty hit and miss when it comes to seeing Black Swifts at anytime, but late spring is a good time to look for this species over the middle and northern sections of Swan Lake.

The Black Swift is quite simply an amazing bird. Dip into its Birds of North America account by P.E. Lowther and C.T. Collins and you'll find it is a species about which very little is known.

Adult Black Swift on nest at Banff, June 2010. Photo by Chris Charlesworth.

Historical changes in Distribution: No information. Migratory behavior: Little information. Physiology: No information. Winter Range: until very recently unknown. Food selection: No info. Daily patterns of vocalizations: No information. You get the picture.

And yet the Black Swift is, for many birders, a fascinating bird, a species of way more interest than just a checkmark on a life list.

For one thing there's the mysteries of its distribution. Look at the bird's range map and you'll see that Cypseloides niger's supposed ranges across the south two thirds of British Columbia (and yet fewer, probably far fewer, than a half a dozen nests have ever been found in B.C.) south through Washington and Oregon (no nests as of my info of 2007) and into California, and east in "colonies" to Colorado, with outposts in New Mexico and Arizona. Then the range appears again in central Mexico and Central America and on some of the Caribbean island. Are the three subspecies of Black Swift really subspecies, or species in their own right. No information.

Secondly, the Black Swift is notoriously FUSSY about its nest sites. An energetic, pioneering researcher in Colorado in mid century, Al Knorr, summarized the species' nest site requirements: a) the presence of water, and not just a pond or an alpine tarn, but usually a waterfall with a spray zone that keeps the nest site damp. In coastal California seepage around crevices in a sea cliff were acceptable as well b) high relief - in other words a site on a cliff or high on the vertical wall of a damp cave c) inaccessibility by predators. A nest on a rock shelf behind the outer spray zone of a waterfall is far less likely to be predated or even detected by some protein hungry predator d) unobstructed flyways and e) darkness.

These characteristics make to Black Swift's nest hard to find, but paradoxically, help reseachers develop   inventories of sites to search. Colorado reseachers have lead ther way for the past several decades in finding Black Swift colonies, although "colony" is a term used very loosely and may mean a site with only one nest. However, Black Swifts have a strong tendency to reuse old nests and many sites have been occupied for many years in a row.

Thirdly, and I personally find this the most fascinating of all the strange facts about this bird, Black Swifts lay a single egg. Of North American land birds, the only other species to lay a single egg is the Band-tailed Pigeon.

The swift's cousins, the Vaux's Swift and the White-throated Swift, both lay multi-egg clutches, but the Black Swift lays one. Its incubation period is very long, 23-26 days, a period common to species that hatch precocial young, like grouse, covered in feathers and almost ready to fly. However, in the case of the Black Swift, after 23-26 days, the chick is born naked and helpless. The young grow slowly and may slip into periods of tropor, an adaptation to long periods between feedings.

While the chick remains in the nest, it may be brooded by both parents at night. When it's older than 20 days, only one parent may stay with it during the dark hours. During the day the parents are generally away soaring around for their principal food, flying ants, which the parent bird binds with saliva into a bolus in its throat pouch. Californian young were fed twice a day.  Once over 30 days of age the chick was brought food only once, in the evening, but perhaps fed several times from the same bolus during the night.

The chick leaves the nest when it is about 44 days old, usually in early September. Once it leaves the nest, that's it. Nests are not revisited until it's time to nest again. The fledgling is presumed to join migratory flocks of adults.

I am deliberately omitting some information about the Black Swift which is quite as interesting as any of the facts herein. If I have whetted your appetite to learn more about the Black Swift, visit the American Birding Association's website to download Rick Levad's book, The Coolest Bird, A Natural History of the Black Swift and Those Who Have Pursued It. Try http//www.aba.org/thecollestbird.pdf

More Red-tailed Hawks

Figure 1 RTHA - white-chested adult with fairly heavy belly band.  Okanagan Landing 3 March 2013. 

This light morph adult has a white chest, fairly strong side of the chest streaking and a fairly heavy belly band. These areas - chest colour and pattern, and extent and heaviness of belly band - are key features I look at when classifying a Red-tailed Hawk. As well, I try to note the darkness of the head, the colour and pattern of the leggings, the colour and pattern of the tail, the darkness and extent of the patagial mark, the colour and patterns of the underwings, the shade of the upperwings and the extent of lightness on the scapulars.

This white-chested, dark belly banded type appears to be common around Vernon.

 Figure 2 shows a close variation on this plumage but with a slightly darker chest and a less heavily marked belly band. Birds of Fig 1 and 2 dominated the Vernon area in the first  half of March this year, probably a normal situation.

Figure 2. Tawny or light brown chested adult with medium belly band. Bella Vista Drive, Vernon 4 March 2013

Figure 3 is an unusual RTHA with a orangey-tinted tan chest and underparts as well as a minimal belly band. Vernon Commonage 4 March 2013.

The Invisible Sparrow

The Invisible Sparrow

Eastern race of Grasshopper Sparrow by Louis Agassiz Fuertes . Plate 81 from Birds of America (Garden City, New York, 1917, 1936). 

Another bird that the North Okanagan used to be well known for is the Grasshopper Sparrow. In 1983 Jim Grant, well known Vernon naturalist, showed me my first Grasshopper Sparrow in the grasslands along Goose Lake Road which connected Old Kamloops Road and the south end of Goose Lake. This site had contained as many as six pairs in 1963 and was well known the THE spot in the province to find this species. Early one late June morning we watched as a tiny sparrow energetically sang its thinly musical song from a tussock of grass east of the summit of Goose Lake Road. This became my go-to spot for the Grasshopper Sparrow from 1989 when my family and I moved to Vernon.

In the 1990s a few large houses were built on the west side of Goose Lake Road eliminating the sparse grass habitat favoured by the sparrows and the road was paved. Thereafter I was unable to find any Grasshopper Sparrows on the west side and the population on the east side dwindled to one singing male, and eventually from 2007 onwards to none.

Meanwhile during the 1990s and the first decade of the 2000s a few more Grasshopper Sparrows turned up – all of them singing males in June or July, never more than two a year. One was on the grassy slopes of Middleton Mountain in a spot now covered by big houses, and another sang in a weedy former horse pasture opposite Desert Cove Estates along Head-of-the-Lake Road.

Both of these locations were good for only a year. At this time I do not know of any spot for this species in the North Okanagan where the public can go. However, if you don’t mind going to the South Okanagan you might find a Grasshopper Sparrow in the grasslands near the parking lot of  Ecological Reserve 100 at the end of Meadowlark Lane off Black Sage Road east of Road 22, or one in the grasslands along the paved road that leads from Highway 3 to the Chopaka border crossing from mid to late May into August. Good luck. Unless the male is singing, the Grasshopper Sparrow is as hard to find as a grassland mouse. As Peter Dunne points out, the birds don't respond to pishing either. 

The Grasshopper Sparrow still occurs in the North Okanagan, but not anywhere that’s open to the public. I have found a tiny handful of individuals on the Indian Reserve and on the Department of Defense lands while running surveys for the land owners, but it would be the unwise birder indeed who dares to trespass on either of those large chunks of land.

Nine things you may not know about the Grasshopper Sparrow:

1.Currently the species Ammodramus savannarum is divided into twelve subspecies. The widespread ones are A.s. perpallidus in western North America and A.s. pratensis east of the Great Plains. One non-migratory population, A.S. floridanus, the Florida Grasshopper Sparrow, is in deep trouble. Despite habitat management in its very limited range north and west of Lake Kissimmee, the Florida Grasshopper Sparrow has been called the most endangered bird in the continental United States. Birds are known from only five breeding sites, and in 2012 steep population declines continued.

2. “Our” Grasshopper Sparrow, A.s. perpallidus, is considered endangered in British Columbia. The only areas where breeding evidence has been found are the Okanagan and Similkameen valleys.

3. The Grasshopper Sparrow belongs to a group of equally reclusive and secretive relatives, Henslow’s Sparrow, Le Conte’s Sparrow, Nelson’s Sparrow, Saltmarsh Sparrow, Seaside Sparrow, Baird’s Sparrow, and two South Americans, the Grassland Sparrow and the Yellow-browed Sparrow.

4. Ammodramus savannarum means sandrunner of the meadows. According to The Handbook of Birds of the World (Vol. 16) the German name for the species is a throat-clearing “Heuschreckenammer”.

5. The female Grasshopper Sparrow builds a grass nest on the ground, often hidden beneath a dome of grasses.

6. According to The Birds of Oregon, in that state east of the Cascades the Grasshopper Sparrow inhabits native bunchgrass remnants on north-facing slopes.

7. The males require elevated perches in their breeding habitats from which they sing their two types of song. Like most Ammodramus species, the Grasshopper Sparrow appears to put a huge effort into delivering its song.

8. It tolerates some shrubs in its habitats but favours the grasses and bare patches between the shrubs. The more the shrubs, the less chance that the sparrow will find the habitat suitable.

9. A fossil bird very similar to the Grasshopper Sparrow was found and dated to be from 10 million years ago. Two major differences were that the dinobird was eleven metres tall and sported a beak almost a metre in length, capable of crushing coconuts. Sorry, I made that up. The fossil was of a very small sparrow, A. hatcheri,  from the late Miocene.

I find magic and wonder in the Grasshopper Sparrow. Imagine this atom of a bird speeding unheaded through the darkness over the Great Basin, oriented we know not how towards Mexico where it will find just the right patch of grasses in which to winter, surviving predation, disease, exposure, and hunger, and towards mid spring with the stars shining in its eyes, it grows restless and in an instant takes flight once again toward the north and a very unsure future. 

Varieties of Red-tailed Hawk Plumage in the North Okanagan

Red-tailed Hawk - brown-chested adult. About 20% of North Okanagan Red-tails are brown-chested.

The North Okanagan is home to more varieties of Red-tailed Hawks than I have seen anywhere else in North America. By varieties I mean plumage varieties,variable plumages being a feature for which the Red-tail is well known.

Red-tails are both resident and migrant in the North Okanagan. For the past several years I have been keeping a rough track of the plumage types I have seen. I haven't formerly analysed my data yet but I have formed some impressions.

The majority of residents are light morph birds, by which I mean they have dark upperparts and lighter underparts. Many, perhaps as many as 25%,  resemble the adult calurus (a widespread western subspecies) illustrated on page 145 of the new (6th edition- 2011) of National Geographic's Field Guide to the Birds of North America.

The image above shows a fairly typical calarus type, though the large white feathers showing in the folded wing are unusual.


About 30% of North Okanagan Red-tailed Hawks are intermediate or dark morph birds, two thirds of these being brown-chested birds like the one shown at the top of this article. Here's another variation of the brown-chested Red-tail

 photographed

Perhaps the most uncommon plumage locally is that of pale birds like this immature shown below ( Swan Lake - 1 March 2013). Some birders are too quick to slap a label like Krider's Red-tail on such a bird. Since we don't know whether the bird is local (which is out-of-range for Krider's) and simply the product of a local genetic mutation, it's perhaps best to call it just a white breasted type.

Complicating matters are Harlan-type Red-tailed Hawks that appear in the North Okanagan as both
birds of passage and as winter residents. Harlan's Red-tail can be dark morph or light morph. It appears that dark morph Harlan's-types are much more commonly encountered in the North Okanagan than light morph Harlan's which I have yet to identify with certainty.

Below is a dark morph immature which could possibly be a dark morph Harlan's type photographed at Okanagan Landing in winter.