The common nighthawk (Chordeiles minor) and
chimney swift (Chaetura pelagica) - local seasonal appearance

These notes were originally based on the timing of 87 observations of two summer residents in Seymour township, Northumberland county, southeast Ontario, 1999-2004. Now updated to 20 August 2024, with 28 observations of the common nighthawk and 168 observations of the swifts. Up until 2024, it seemed that the insectivores such as swift and nighthawk, tree and barn swallow, all flew south from here no later than 19-30 August. Both the swifts and the nighthawks winter in northern South America, and so the sharply-defined summer residence period in our neighboourhood is readily understood.

Regional picture: In the wider Kingston (west to Prince Edward county) area along the north shore of Lake Ontario (Weir, 1989, pp.274-276, 278-280) the nighthawk has long been reported as a mid-May arrival: the settlement period afforded the bird many more clearings, plus the innovation of secure flat gravel roofs, for choice nesting sites (see also Merrill, 1954, pp.121-125). Reverse migration is underway by mid-August, with groups of up to 10 birds, and sometimes much larger, as in 300 birds reported at Kingston on 26 August 1977. A chimney swift banded near Kingston was recovered in Peru in 1944, demonstrating the range of these tiny yet agile and tenacious birds (McNicholl, 1994). Spring and autumn roosts of great numbers of swifts were reported around Kingston, including a flock of 10,000 on 14 May 1947 (see also Forbush and May, 1939). Average arrival is 26 April and average departure 05 October. Across Lake Ontario in New York state (Levine, 1998, pp.pp.341, 344-345) the nighthawk was by that date recorded in decline, though still "a common to abundant fall migrant", peaking in late August and early September. The chimney swift was at the same time noted as a widespread breeder and "common to abundant migrant, especially inland, occasionally very abundant". The swifts typically reach New York in the latter half of April and depart in early to mid-October. The typical migration times of these birds through Presqu'ile is around mid-May and mid-September (nighthawk) and late April and early October (chimney swift: LaForest, 1993, pp.218,221). In the Peterborough county region (Sadler, 1983, pp.99-100) nighthawks have been noted heading north as early as 12 April, and south again in late August, or even as late as 13 November, 1975. Sadler reports large southbound flocks in the past in August, e.g., 500 one day in 1958, and 200 in 1967. Sadler lists the chimney swift as a common summer resident, extreme dates being 21 April and 06 October. Swifts, nighthawks and swallows were NOT amongst 58 species whose plight was highlighted by the Ontario Rare Breeding Bird Program, nor amongst 22 additional northern species spotlighted in that review (Austen et al., 1994). It is important to view the bigger picture, which includes eastern North America and, indeed, much of the Americas, in terms of the worldwide distribution of each of these far-flung species. Epic migrations may still persist elsewhere in the continent: 30 years ago, some 1,300 common nighthawks were seen in 90 minutes at Delta, north of Winnipeg, Manitoba (Whelan, 1993).

Bird expert Pete Dunne (2022) described a short (1 or 2 mugs- of- coffee length) observing period on the Delaware Bayshore, in southwestern New Jersey, some 600 km S.S.E. of Trent Hills. The observations were made one mid-August morning, almost certainly (though not explicitly stated) in 2021. The salt marshes on the east side of Delaware Bay run north from the famed birding hot-spot of Cape May. Assorted swallow species, and a huge transient population of purple martins occur here, along with many ospreys, and other birds. Dunne also notes "chimney swifts, as omnipresent as crickets this time of year. On trembling wings, scores of swifts cut cookie-cutter patterns over our town, feasting on the insect riches of the Bayshore". That's a relief: swifts seem to be doing well in other places, even though our local population has plummeted.

Leslie Anthony (2020), writing in Canadian Geographic, reviews Humanity's variable (determined to stumbling to non-existent) efforts at stabilizing biodiversity. Buried in his good review are some worthy morsels, food for thought. Here are just two of these:

• Bridget Stutchbury (York University) is quoted as estimating the cost of improving the status of one endangered bird species at 1 million dollars a year and that, by extension, "if every taxpayer in North America gave $10 each year, we could probably save everything (in North America)" (ibid., p.63). Collectively, we have the money. No doubt - because habitat degradation is a key driver of biodiversity loss - in many cases the actions taken to help one species would help many others, at no extra cost.
• The second point is especially relevant to attempts at documenting regional biodiversity, such as the natural history listings and species profiles on this web site. Anthony cites fisheries scientist Daniel Pauly (University of British Columbia) as identifying, in 1995, a phenomenon known as shifting baseline syndrome (ibid., p.66). This refers to a tendency to overlook the past. In our case, every generation of scientist- naturalists reviews their chosen field as their careers progress, and inevitably looks back 10, 20, 40 or more years, to the conditions that applied when they began. But factors such as, say, the number of nighthawks seen in one area in a summer, will have varied for millennia, and certainly back to a time when human activity had essentially zero impact on most wildlife populations. At the very least, we need to seek the advice of our elders, while they are still with us, and to hunt the relevant literature for clues to past conditions.

Here are the complete 25-year (1999-2023) monthly data summaries for the nighthawk (73-kb pdf file) and the chimney swift (75-kb pdf file), updated into August 2024. The chimney swift chart includes data for sightings at a church chimney in June-August 2024. Both species were covered in the Ontario provincial breeding bird surveys (Cadman et al., 1987, 2007).

The common nighthawk

The nighthawk belongs to the goatsucker family (Bent, 1940; Lawrence, 1974). The earlier seasonal-residence estimate of 13 May to 25 August remains, though one report has since been made for the first week of September. Whereas swifts construct their own nest, nighthawks may elect to lay their eggs on bare ground, or a flat gravel roof. The species was widespread in the 1980s, although there were indications of a declining population: the bird bred across almost all of Ontario, thus data from a small area may be of limited value. Indeed, there were few reports mapped in for the area from Rice Lake to Belleville (Cadman et al., 1987, pp.220-221). 20 years on, the decline continued (Cadman et al., 2007, pp.308-309), possible reasons including loss of habitat (infill of clear-cuts in forests in the north, and decline in gravel roofs in the south), loss of food sources (to insecticides, and even insect roadkill: Anthony and Chua, 2015) and urban nesting predation by gulls and crows. Thus by 2007 it was "rare to locally uncommon south of the Shield".

The chimney swift

Now noted here from 11 May to 19 August. In contrast to the nighthawk, swifts do not generally breed north of Lake Superior, but occur from roughly the latitude of Timmins southward across all southern Ontario (Cadman et al., 1987, pp.226-227). 20 years on, the lovely swift was indeed much less common, and "the demise of the old-fashioned chimney appears to be a large factor in the decline" (Cadman et al., 2007, pp.314-315). Furthermore, "the species has declined markedly over at least the past 40 years". Some areas such as the Haliburton district and southern Algonquin park maintained their populations better than elsewhere in the province, perhaps because older forests afford more nest sites (ibid, p.315). Stokes (1979, pp.84-92) notes that chimney swifts fly north in smaller flocks of maybe 20-30 birds in spring, but may return in late summer in flocks numbering in the hundreds. Pairs of swifts make nests in high accessible places, including chimneys and under the eaves of tall barns. Typically just one pair nests in a given chimney, so eaves and other nest opportunities are important. In contrast, especially as the fall migration begins, large groups may seek communal roosts, as in larger chimneys. Because of the cloistered, remote or hard-to-access locations of swift nests, it is hard to know how the birds behave when out of view. Althea Sherman (1853-1943), sometime inspiration to storied Ontario naturalist Louise de Kiriline Lawrence, undertook a pioneering study of swifts (Simonds, 2022, pp.190-193). She had a wooden nest tower built at home in Clayton county, Iowa, and for the first four decades of the 20th century compiled an unrivaled set of notes on the life of this bird. The 28-foot-high tower was designed to afford views of the birds as they went about their summertime lives.

A word from renowned ornithologist Earl Godfrey (1979, p.228): "Swifts are well named, for they are indeed fast flyers. On calm summer evenings they may fly so high as to be mere specks in the sky, and their voices, like the clicking of knitting needles, drift faintly down to earth".

One wonders what swifts did prior to the widespread European settlement in our region: a brick chimney is a recent thing, here, and 200 years ago there would have been few such to the north of the shore of Lake Ontario! What was the norm then, and in centuries before? The swifts presumably were here, their preferred nest and roost sites in hollow trees.

Three distinct styles of swift house were built by kind enthusiasts circa 2010, but all have failed to attract clientele, as far as we know. Possibly less woodworking skill, and more knowledge of masonry and bricklaying is key to building a successful chimney swift house, that the birds will use and return to each summer. The rough surfaces of unfinished brickwork seem ideal, rather than wood or other materials.

The summer 2024 experience of seeing swifts roost in a church chimney in Campbellford was both reassuring and a source of wonderment. The birds flit so fast across the sky, generally inconspicuous in the twilight. They often approach the chimney, then shoot off at right-angles, maybe in search of a last mosquito or two. Then, singly or in little groups of as many of 7-8 birds, they return to the chimney and appear to drop vertically, in a corkscrew motion, wings and tails spread (which makes them look bigger, like a clump of falling leaves), until they enter for the night. None were seen to exit the chimney, after entering.

Barn swallows and chimney swifts are hard to habituate to using artificial nesting boxes and kiosks, hence the importance of saving old, open-topped chimneys used as roosts (Scallen, 2018), and allowing the swallows to continue their habit of nesting under the eaves of barns.

In conclusion, while the nighthawk seems to have abandoned our area, or at least diminished to the point of rarity, the chimney swift can still be seen, in summer, tracing its acrobatic trails over water, in pursuit of insect prey. Arriving in Canada in 1981, later years in Toronto impressed on me an iconic status for both birds. The nighthawk would make its nasal "peent" calls while hunting over the St. George campus of the University of Toronto. One late summer in the 1980s, we experienced the wonder of a southbound flock of nighthawks passing overhead, southbound, over a cemetary of the south side of Timmins. Based on the past 26 summers, future local sightings of both species may be made or, at the least, a search initiated, along the river Trent, and in town on the right (west) bank, where the swifts have reliably been sighted in 2024.

References

Anthony,L (2020) The sixth extinction. Canadian Geographic 140 no.5, 58-67, September.

Anthony,L and Chua,C (2015) We know that insect species are being lost across the planet, but no one is really looking. Canadian Geographic 135 no.6, 50-58, December.

Austen,MJW, Cadman,MD and James,RD (1994) Ontario Birds at Risk: Status and Conservation Needs. Federation of Ontario Naturalists / Long Point Bird Observatory, 165pp.

Bent,AC (1940) Life Histories of North American Cuckoos, Goatsuckers, Hummingbirds, and their Allies. Dover Publications, Inc., reprint of Smithsonian Institution Bull. 176, in 2 volumes in 1964 / as 1 volume in 1989, 506pp.

Cadman,MD, Eagles,PFJ and Helleiner,FM (1987) Atlas of the Breeding Birds of Ontario. Federation of Ontario Naturalists and Long Point Bird Observatory, published by University of Waterloo Press, 617pp.

Cadman,MD, Sutherland,DA, Beck,GG, Lepage,D and Couturier,AR (editors) (2007) Atlas of the Breeding Birds of Ontario, 2001-2005. Bird Studies Canada,Environment Canada,Ontario Field Ornithologists, Ontario Ministry of Natural Resources, and Ontario Nature, 706pp.

Dunne,P (2022) Got to make the morning last. Birdwatching 36 no.1, 14-15, January.

Forbush,EH and May,JB (1939) Chimney swift. In `Natural History of the Birds of Eastern and Central North America', Houghton Mifflin Company, Boston, MA, 554pp., 284-286.

Godfrey,WE (1979) The Birds of Canada. National Museums of Canada, 428pp.

LaForest,SM (1993) Birds of Presqu'ile Provincial Park. Friends of Presqu'ile Park / Ontario Ministry of Natural Resources, 436pp.

Lawrence,RD (1974) Wildlife in North America: Birds. Thomas Nelson and Sons (Canada) Ltd, Don Mills, ON, 256pp.

Levine,E (editor) (1998) Bull's Birds of New York State. Comstock Publishing Associates, Cornell University Press, revised version, 622pp.

McNicholl,MK (1994) Bird-banding and bird observatories in Ontario: 1905-1989. In `Ornithology in Ontario' (McNicholl,MK and Cranmer-Byng,JL editors), Ontario Field Ornithologists Spec.Publ. 1, 400pp., 112-148.

Merrill,A (1954) Wings in the Wind. Ryerson Press, Toronto, 172pp.

Sadler,D (1983) Our Heritage of Birds: Peterborough County in the Kawarthas. Peterborough Field Naturalists / Orchid Press, Peterborough, ON, 192pp.

Scallen,D (2018) Nesting instincts. ON Nature 58 no.1, 30-34, Spring.

Simonds,M (2022) Woman, Watching. Louise de Kiriline Lawrence and the Songbirds of Pimisi Bay. ECW Press, Toronto, 404pp.

Stokes,D (1979) A Guide to Bird Behavior, Volume 1. Little, Brown & Company, 336pp.

Watson,A and Nigmanova,K (2012) The state of the Avian nation. Canadian Geographic 132 no.6, 24-25, December.

Weir,RD (1989) Birds of the Kingston Area. Quarry Press, 608pp. plus map.

Whelan,P (1993) Braggarts take a tern for the better. Globe and Mail, 11 September.

Wilson,GC (2019) Wings at dusk. Trent Hills Tribune, 19, September.