THESE THREE WELL-GROWN fawns at Six Mile Lake may be triplets or may just be hanging together while the does are off somewhere nearby. After more than three months, they’re grazing rather than nursing and have all but lost their spots. (Betsy Bloom/Daily News photo)

The deer are going gray — even the youngsters.

The fawns are quickly losing their spots, as their coat begins to make the switch from rust orange to the ash and brown color that will better blend in among branches and tree trunks in the winter woods.

This also usually is a sign the fawn is old enough to be weaned. The ones I photographed in the yard this week all were steadily nibbling the lawn and foliage, testing what might taste good, I imagine.

Hopefully they don’t discover the hostas, although the does long since have reduced those to nothing but stem stumps.

The winter coat of a white-tailed deer is well-suited to withstand even extreme cold, according to the University of Georgia. As expected, it is thicker and longer than the summer coat — though, surprisingly, not as dense, researchers said. But a key element is each hair is hollow, providing good insulation, like the puffy parkas we might wear.

In addition, the deer have a wooly layer underneath that keeps body heat close to the skin. It’s much the same as bird down retaining warmth, so even small birds seem impervious to winter’s chill.

Finally, deer are able to produce an oily substance that, worked through the coat makes it almost waterproof.

But once this new coat is in place, it will make it a lot tougher for deer to cool off if summer-style temperatures linger into autumn, as deer have few sweat glands, experts said. Hunters know a warm opening day can mean seeing few deer, as they bed down until the cool of the evening rather than overheat.

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We’ve had twins hanging around our property this summer but only recently have what appeared to be triplet fawns shown up. I suspect the neighbors’ well-laden apple trees are the reason; the first time the three fawns appeared was under the trees.

If they stay, it will be the second year in the past three we’ve had a doe with three fawns. The previous super-mom kept her trio thriving until spring, including one that was the darkest whitetail deer I’d ever seen.

But another explanation could be at play here — does and fawns, even some of the younger bucks, start to herd up again at this time of year. These could be fawns from different does, as we’ve seen a doe with a single fawn this year along with the doe with twins.

As you can see above, no doe was visible when these three were wandering around sampling the greenery and none showed up when the fawns finally went trotting into the trees.

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Staying on the deer theme, a few readers reported bucks in their areas have begun rubbing off antler velvet, a sign of pre-rut. This is about on schedule, with most mature bucks starting this behavior by mid-September.

The one buck I’ve reliably seen at Six Mile Lake Road still had velvet on this week, but he’s a gangly spike yearling that probably hasn’t really felt that surge of hormones enough to start rubbing and marking.

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Most of the birding lists I follow say hummingbirds have become scarce, which is to be expected, considering how far they will travel — central and South America — to reach wintering areas.

But it’s still a good idea to keep those hummingbird feeders out. The ones that were here this summer might have moved on but another wave could be yet to come from the north or even west.

And, as always, watch for ones this fall that look different, especially if they have a copper or rusty hue, as it might be a rufous hummingbird gone off its normal western range during migration.

This species turns up almost annually in Wisconsin, though they are the most northern hummingbird species in North America, nesting even into eastern Alaska.