Subspecies of the Horned Lark

by Ron Pittaway

Prairie Horned Lark at Keswick, Ontario, showing the erect "horns". 21 March 2005.

Revised January 2014. First published in Ontario Birds 12 (3): 109-115. December 1994

Introduction

The very first recognizable forms I learned as a young birder were the Prairie Horned Lark (Eremophila alpestris praticola) and the Northern Horned Lark (E. a. alpestris). These two subspecies were often mentioned by John Bird in his Saturday column in the Ottawa Journal. As an example, he reported on 6 February 1965, "Earl Godfrey found three Northern Horned Larks near Fallowfield. He had a close enough look to identify them as Northerns. Prairie Horned Larks would have been more suggestive of migration."

In what follows, I discuss the differences in coloration, size, behaviour, song, migration, habitat, breeding times and ranges which taken together distinguish the three recognizable forms of the Horned Lark in Ontario.

Taxonomy

The American Ornithologists' Union (AOU) (1957) and Godfrey (1986) list four subspecies of the Horned Lark in Ontario: nominate E. a. alpestris, E. a. praticola, E. a. hoyti and E. a. enthymia. The listing of enthymia in Ontario by the above authorities is based on Snyder (1938) who collected specimens in western Rainy River District for the Royal Ontario Museum. However, James (1991) who re-evaluated Snyder's work does not list enthymia in Ontario because the Rainy River birds are "more like praticola than enthymia". Peters (1960) treats enthymia as "doubtfully distinct" from the more western leucolaema. Affinities of enthymia and leucolaema require study (Godfrey1986). Below, I discuss enthymia in more detail under the Saskatchewan Horned Lark.

Plumages, Molts, Ageing and Sexing

Horned Larks have only two plumages: juvenile (juvenal) and adult (definitive basic). The briefly held spotted juvenile plumage is quite unlike the adult and has tempted some birders to believe they have found a rare pipit or longspur. See the illustration of a juvenile on page 367 in the National Geographic Guide (Dunn and Alderfer 2011) and the photograph on page 297 in Volume 2 of the Master Guide (Farrand 1983).

Horned Larks acquire their first adult plumage by late summer of their hatching year (Earl Godfrey, pers. comm.}, Unlike most birds, the post-juvenile (preformative) molt is complete (all feathers). First year adults are on average duller and with more spots than older adults; extremes may be separable with experience (Pyle 1997).

On males, the black collar, mask, crown and "horns" (erectile feathers) are more distinct than on females. Males are also larger than females. Adults have one complete molt a year after breeding but before fall migration. On fresh fall and slightly worn winter birds, the black markings on the head (including "horns") and breast are obscured by pale feather fringes and the birds are more pinkish, buffy and streaked (Figure 1). There is no prebreeding (prealternate) molt. The breeding dress is acquired by the gradual wearing away of the feather edgings, bringing the black markings into prominence. During the breeding season, the normally inconspicuous "horns" are often erected in display. Note that birds depicted in field guides are in worn, not fresh, plumage.

In summary, Horned Larks have the same plumage year round but the appearance of fresh fall birds is markedly different from worn spring and summer birds. See Ridgway (1907), Bent (1942) and Roberts (1955) for detailed plumage descriptions of each subspecies.

Figure 1. Adult male Northern Horned Lark in fresh plumage. Drawing by Peter Burke.

Prairie Horned Lark (E. a. praticola)

The Prairie Horned Lark breeds commonly in southern Ontario south of the Canadian Shield, locally and sparsely in farming areas north to the Clay Belt, as well as in western Rainy River District (James 1991). The breeding range of the Prairie subspecies is separated from the breeding ranges of the two northern subspecies by a wide band of boreal forest.

Small numbers of Prairie Horned Larks winter southern Ontario, but are normally outnumbered by the Northern subspecies (Dennis Rupert, pers. comm.). Prairie Horned Larks are very early spring migrants (earliest land bird) arriving in numbers north of Lake Erie by early February and north of Lake Ontario by mid-February. Prairie birds are usually paired, and males are singing on territories when the first flocks of Northern Horned Larks move through southern Ontario (Devitt 1967, Sadler 1983). The top of Figure 4 shows a typical early March scene near Toronto with a "skylarking" male Prairie Horned Lark singing over its breeding territory.

Separation of Prairie and Northern Horned Larks is usually straightforward. The superciliary (eyebrow) stripe is white in the Prairie (sometimes very pale yellow in front of the eye) (Figure 2) whereas the superciliary stripe is usually bright yellow in the Northern (Figure 3). A typical Prairie Horned Lark in worn plumage is illustrated on Plate 55 in The Birds of Canada (Godfrey 1986). Peterson (2008) illustrates both Prairie and Northern subspecies on page 296. A Horned Lark singing in southern Ontario is the Prairie subspecies.

Note that the Hoyt's Horned Lark is larger but very similar in appearance to the Prairie subspecies; see discussion under account of Hoyt's Horned Lark below. 

Figure 2. Prairie Horned Lark at Keswick, Ontario, 22 March 2005 

Northern Horned Lark: (E. a. alpestris)

The nominate subspecies is the northeastern form. It breeds from "northern Quebec and northern Labrador south to southern James Bay, southeastern Quebec (Gaspe Peninsula, Madeleine Islands), and Newfoundland" (Godfrey 1986). It intergrades with E. a. hoyti in northern Ontario (James 1991). See the discussion below under the heading "Intergrades".

In southern Ontario, Northern and Prairie Horned Larks have different migration and behaviour patterns that help to distinguish them. In spring, Northerns migrate later than Prairies with numbers peaking from March to mid-April after most Prairies have begun nesting. Northern Horned Larks do not sing during winter and on spring migration in southern Ontario. Farther north in Algonquin Park, Tozer (2011) shows the different spring migration times of Prairies (28 February to 1 April) and Northerns (13 April to 4 June).

Peter Burke's illustration at the bottom of Figure 4 shows migrant Northerns in early May at the airfield in Algonquin Park. A few early Northerns probably reach James Bay in April, but most arrive there from mid-May to early June (Manning 1952, Manning 1981, Todd 1963).

In autumn, the first Northerns arrive in southern Ontario by mid-September and peak through October with numbers falling off in November. Dates in Algonquin Park for Northerns range from 6 September to 21 November (Tozer 2011). Unlike Prairie birds, flocks of Northerns are often seen along the shorelines of the Great Lakes in autumn. Small numbers of Northerns winter in southern Ontario, rarely north to Ottawa, and normally outnumber the Prairie subspecies in mid-winter (Tozer and Richards 1974, Weir 1989 and Dennis Rupert, pers. comm.).

Compared with the Prairie subspecies, the Northern is larger and more robust (noticeable in the field) and the eyebrows, forehead, cheeks and throat are distinctly yellow (Roberts 1955, Todd 1963).

Figure 3. Northern Horned Lark near Oshawa on 14 January 2014

Hoyt's Horned Lark: (E. a. hoyti)

Hoyt's is the northcentral subspecies. It breeds on the “arctic islands south to northeastern Alberta, northwestern Saskatchewan, northeastern Manitoba, extreme northwestern Ontario (Fort Severn)” (Godfrey1986). It intergrades with alpestris along the coast of Hudson Bay in Ontario (James 1991).Hoyt's migrates mainly through the Prairie Provinces (Taverner 1937) and is a regular migrant from Lake Superior westward (Alan Wormington, pers. comm.).

Hoyt's is a large bird like alpestris but similar in appearance to the smaller praticola, typically with a white supercilium and pale yellow restricted to the middle of the throat (Ridgway 1907, Roberts 1955).

It is a rare to uncommon migrant and winter visitor to southern Ontario usually mixed in with large flocks of Northerns. For example, Don Sutherland, Bill Crins and Rory MacKay found one Hoyt's among 83 Northern Horned Larks and four Lapland Longspurs (Calcarius lapponicus) in Algonquin Park on 7 October 1984 (Tozer 2012). Sutherland (in litt.) describes the Hoyt's as being “conspicuous amongst the Northerns” with its “white supercilium, forehead, throat and breast; the latter two features showing just the faintest hint of yellowish wash”. In addition, Don Sutherland (in litt.), Paul Pratt and Alan Wormington visited a feeder in Leamington in February 1982, “where a wintering flock of Horned Larks contained many praticola and two hoyti amongst the predominant alpestris. There, compared side by side, the hoyti dwarfed the otherwise similar praticola, and seemed larger and distinctly paler than alpestris”, However, the paler colour may only be obvious when the birds are compared side by side.

Dates for Hoyt's in southern Ontario, based on specimens in the Canadian Museum of Nature, range from 22 September to 26 May (Bruce Di Labio, pers. comm.).

Figure 4. Top: Adult male Prairie Horned Lark in worn plumage and breeding birds on territory near Toronto in March. Bottom: Adult male Northern Horned Lark in worn plumage and May migrants in Algonquin Park. By Peter Burke.

Saskatchewan Horned Lark (E. a. enthymia)

This pale subspecies of the Prairie Provinces is listed by the AOU (1957) and Godfrey (1986) for extreme western Ontario based on Snyder (1938). However, James (1991) states, “The birds from western Rainy River, considered by Snyder (1938) to be enthymia from the central prairies, are darker than birds from Manitoba, and scarcely lighter than birds from southern Ontario. The western birds may be somewhat intermediate, but are more like praticola than enthymia, in my estimation”. Therefore enthymia is not listed for Ontario (James 1991).

Nevertheless, observers in the Rainy River area should check flocks of smaller Prairie Horned Larks for similar-sized but very pale Horned Larks suggestive of enthymia. See the illustration (poor quality) on page 367 in the National Geographic Guide (Dunn and Alderfer 2011).

Intergrades

Subspecies are not species and by definition interbreed freely where their ranges meet. Intergrades are birds showing characteristics intermediate between two subspecies (Earl Godfrey, pers. comm.). Most breeding birds along the Ontario coast of Hudson Bay are intergrades between alpestris and hoyti. James (1991) states, “Birds from northern Ontario may be similar to either hoyti, paler yellowish about the head with a less vinaceous colour, or to alpestris, with strong yellows and darker backs. Most, however, are intermediate with rather paler yellows and more vinaceous backs.” Therefore one may encounter intergrades in southern Ontario, but most migrants should be either pure alpestris or pure hoyti because the large populations of each subspecies greatly outnumber the much smaller population of intergrades. This is borne out by specimens in the Canadian Museum of Nature (Michel Gosselin, pers. comm.).

Summary

The identification of Prairie and Northern Horned Larks is usually straightforward in southern Ontario where most larks are either one or the other. Hoyt's Horned Lark is a rare to uncommon migrant and winter visitor to southern Ontario, normally found associating with flocks of Northerns. Hoyt's is a large subspecies like the Northern, but very similar in appearance to the smaller Prairie, and should be identified with caution. The identification of subspecies should be based on a number of characteristics taken together. Be aware of intergrades, and remember, you just cannot identify all birds to subspecies.

Acknowledgements

I thank David Agro (Academy of Natural Sciences of Philadelphia), Peter Burke, Bill Crins, Bruce Di Labio, Earl Godfrey, Michel Gosselin (Canadian Museum of Nature), Jean Iron, Ross James (Royal Ontario Museum), Dennis Rupert, Don Sutherland, Ron Tozer, Mike Turner and Alan Wormington for much valuable advice and assistance. A study such as this is only possible because of the information gained from the staff and collections at the Canadian Museum of Nature, the Royal Ontario Museum and the Academy of Natural Sciences of Philadelphia. Once again, I am indebted to Peter Burke for his marvellous illustrations and strong support for the concept of recognizable forms.

Literature Cited

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