The subspecies of Horned Lark are pretty complicated.
Here's a good article about the subspecies occuring in Ontario:
http://www.jeaniron.ca/2010/hornedlark.pdfShort summary:
The breeding subspecies in southern Ontario is the Prairie Horned Lark
praticola. Small numbers winter and they are very early spring migrants (February), so they should be here by now. It has white or very pale yellow eyebrow and throat.
The Northern Horned Lark
alpestris breeds in Quebec, Newfoundland and Labrador and usually outnumbers Prairie Horned Larks in mid-winter in southern Ontario. They migrate from March to mid-April, later than the Prairie Horned Larks. It is larger and darker and the eyebrow and throat is clearly yellow. The Horned Larks in the picture at
http://outdoorontario.net/birds/phpBB/v ... php?t=4711 are Northern Horned Larks.
Hoyt's Horned Lark
hoyti breeds in the northern part of the prairie provinces. It is a rare to uncommon migrant and winter visitor in southern Ontario and is similar in colour to the Prarie Horned Lark, but is considerably larger. I don't have personal experience with this subspecies, but I think it's hard/impossible to distinguish between Hoyt's and Prairie Horned Larks without a size comparison and the Prairie Horned Lark would be much more likely.
/Thomas