Male Monarch Butterfly, Danaus plexippus. The dots on the hindwing indicate the male.
Last night at around 5 PM I was in the yard and happened to look up. The sky was dark, and the clouds were low, looking like imminent rain. Against the clouds were, what I estimate conservatively to be, 200 Broad-Winged Hawks. They were circling and soaring and moving west along the north shore of Lake Ontario. Hawks will not fly over large bodies of open water if they have a choice so here in Ontario the hawks migrate south until they reach Lake Ontario and then fly west. Once past the west end they will turn south again until they reach Lake Erie where they will again turn west. This tends to create concentrations of raptors along the northern shores of the lakes. In a few places such as Cranberry Marsh in Whitby, Rosetta Maclain park in Scarborough, and Hawk Cliff south of St. Thomas, birdwatchers have organized fall hawk counts. If you are interested they will welcome you and point out some of the hawks as they fly overhead. For more info check this document.
Birds aren't the only migrants right now. This morning I took the boys for a little walk to Samuel Wilmot Nature Area in Newcastle. The place was alive with Monarch butterflies. In the hour that we were there I would guesstimate seeing 200 of them. They didn't seem to be actively migrating at the moment, more feeding up, but I imagine as soon as the winds are favourable they will be on there way south to Mexico.
What made it more interesting was the nummber of other butterflies that were about this morning. In one spot I saw Monarchs, Mourning Cloak, Red Admiral, Question Mark, and Viceroy as well as Cabbage and Sulphur butterflies. There were also a few Pearl(?) Crescents around to represent the smaller butterflies.
Question Mark, Pologonia interrogationis
Red Admiral, Vanessa atalanta
As well as all the butterflies there was a tremendous number of large dragonflies flying about. I am afraid I cannot ID the dragonflies but there were blue and green darners as well as a few others such as the one pictured below! There were also 7 or 8 hummingbirds going thru which made for some interesting dragonfly vs hummingbird encounters.
PS did some 'net research' and think the above dragonfly is a 12 Spotted Skimmer.
So this gist of migration time is to keep your eyes up and down and to the side. Heck, just keep them open!!!