Animals that migrate don’t need to see the first frost or the first few inches of snow to get the message to move farther to the south.

In fact, most of the bird migrations are keyed by the shrinking amount of daylight. Some avian migrators, like hummingbirds, heed the signals for two reasons.

Most of the hummers travel a great distance to Central or South America to find the nectar where flowering plants bloom year-round. The other reason, of course, is they are not adapted to the frigid temperatures that late autumn and winter bring.

It has been a gradual process, but by now you’ve noticed that the robins have left your backyards. They could still find enough food here, but their ancestral roots didn’t include having nicely manicured lawns with the ease of find earthworms, insects and your blueberries or cherries. They adapted to life in forest clearings.

Over the past few weeks, I have seen loose flocks of 10 to 15 robins or more scatter as I’ve driven a few back roads, and on one of my short nature forays into our woodlands.

Over the next month or so, if you live near a woodlot, don’t be surprised to see small flocks “pop out” of the trees and fly overhead just before dark. They’ve gotten the message and it’s time to move.

Raptors migrate, too. Ospreys, whose populations are greater around Canadian and New England lakes where most feed and nest, need to move because it is impossible to dive through ice-covered lakes to fish.

Most of them also travel very far south so their migrations need to start earlier. Hawk Mountain and Bake Oven Knob hawk counters are already logging them passing south through our region.

One raptor that makes a long migration to Peru, Columbia, Venezuela, etc., is the broad-winged hawk. Some of them breed here in the Times News region, while many thousands more breed throughout the Canadian provinces and New England.

Their migration is very predictable, and in fact, occurs in a narrow window. Most of the thousands that migrate, do so between Sept. 10 and Sept. 20. A few have already made their way through the area, but the big “rush” is yet to come.

Another reason they migrate earlier is because snakes are a diet staple. Being cold blooded, most snakes head to winter denning areas by mid-October and are no longer available for the broadies.

Broad-winged hawks also migrate a bit differently. They use thermals and not wind deflecting off the ridge tops. They join other broadies, and you could see a kettle of dozens or even 100 at a time swirling overhead.

I can’t predict the best day, but a warmer mid-September day with light southwest or little wind, might be the day for you to take the drive to the top of the Blue Mountain and pull out a lawn chair and watch the show. I know, and will remind you, that since they use thermals and fly higher and higher, by midday

They may be so high they could be hard to spot. I like the 9-11 a.m. time frame when they may be gliding just above the tree line at Bake Oven Knob.

Enjoy your time outdoors. The calendar is showing Sept. 13: Peak bird migrations are happening now, so get out there.

Test Your Outdoor Knowledge: In this column I referred to broad-winged hawks migrating in huge numbers at the peak of their season in September. The highest daily total recorded passing Bake Oven Knob was ____. A. 1,450; B. 3,035; C. 4,100; D. 5,655.

Last Week’s Trivia Answer: Some male butterflies gather at mud puddles to get needed salt and minerals, and don’t kill me, but it is called puddling.

Email Barry Reed at breed71@gmail.com