CENTRAL MINNESOTA - Since the early 1970s, I've hunted grouse in this part of the state. Three dogs have come and gone, and a fourth dog, now riding with me in his kennel in the back of the truck, is 11 years old. Axel, a Deutsch Drahthaar, is gray in the face. His right rear hip causes him pain. Let's face it; his hunting days are numbered.

I thought about this at dawn on Saturday morning, opening day of the 2011 Minnesota ruffed grouse season. I was driving along familiar roads toward celebrated grouse haunts. A lot more than just dogs has changed during the almost 40 years I've tromped these woods hoping to flush a grouse or two.

The habitat has changed. So have the inhabitants.

During my drive I saw two flocks of wild turkeys. A decade or two ago I would not have imagined, even in my wildest of wildlife dreams, that turkeys would live and thrive here.

En route to my grouse haunts, I also saw sandhill cranes. Oh, there may have a been a crane or two around back in the '70s, but now the large, battleship-gray birds are common. If you don't see them, you've surely heard their loud, prehistoric-sounding calls.

Timber wolves now live here, too. During December grouse hunts I see their huge prints in the snow. Their deer-hair-filled scat is a common sight, though I rarely see the wolves themselves. Back in the '70s this was primarily coyote country.

Perhaps, though, the biggest change that has occurred since I began hunting this area is the habitat. The change is not noticeable unless you look through the eyes of a grouse hunter.

As grouse hunters know, Old Ruff likes aspen forests. Much to the delight of the grouse, loggers like aspen, too. When an aspen forest is just right for cutting, it's mostly beyond the ideal age to support a thriving ruffed grouse population.

My first stop of the morning illustrated this very well.

During the '70s and '80s this chunk of state land was a haven for ruffed grouse. It contained all of the habitat variables needed by the forest birds. There was an alder and willow slough that gradually rose to the ideal ruffed grouse fringe habitat containing a mix of gray dogwood and hazel that grew beneath a canopy of mixed-aged aspen. Higher still was a ridge of jack pines where, on a blustery December day, a grouse hunter could often find his prey seeking refuge.

Slowly but surely the forest matured. As a grouse hunter, I didn't notice it at first. "This spot just isn't as good as it used to be," I'd say to my friends. But we'd hunt the land anyway.

Then it hit me. Gone were most of the dogwoods, shaded out by the maturing aspens. The sun-seeking hazel was gradually thinning, too. I eventually realized the once-prime grouse hunting location had aged to a point beyond what a ruffed grouse prefers to call home.

Now, on Saturday, as I loaded my shotgun and prepared Axel for the hunt, the habitat was totally different. A decade or so ago, the loggers had arrived. They accomplished, in one winter, what Mother Nature would have taken years to perform. Now the dogwood and hazel are back, and so is a nice mix of young aspens. The loggers left enough mature aspens to feed winter grouse.

Axel and I hunted three such spots on Saturday. Although we flushed only five ruffed grouse (two ended up in the bag) in about three hours of tromping the woods, our low flush rate was not a product of hunting "old" spots that are no longer able to supply a ruffed grouse with the necessary components to live. A poor hatch this summer might be to blame. Or perhaps we simply zigged when we should have zagged.

I, like Axel, am getting a bit gray, too. With those gray hairs comes the wisdom that as ruffed grouse habitat changes, so must the hunter.

Bill Marchel, an outdoors columnist and photographer, lives near Brainerd.