OLIVIA, MINN. – A crescent moon still shimmered in the sky at dawn one day last week when the first gobble echoed from dark woods about 100 yards to the north.

Then four or five other tom turkeys joined the chorus.

"They're everywhere," whispered Dave Swenson, who hunkered in a-tent-like blind with me.

Swenson and I weren't hunting. We had gotten up at 4:30 a.m. to tag along with our friend, Tom Kalahar, while he hunted near a bluff overlooking the Minnesota River Valley.

Camouflaged head to toe, Kalahar, 63, sat against a tree just outside our blind, a crossbow in his hand instead of a shotgun, hoping to bag one of the big tom turkeys that gobbled incessantly nearby.

This is the third year that Minnesota hunters age 60 and older can use a crossbow to take a wild turkey. And beginning last year, archers, including those using crossbows, have been allowed to hunt the entire 45-day turkey season, in any zone.

Tom Kalahar took this tom a year ago using a crossbow. He waits for a bird to get within 30 yards before shooting.

Shotgun hunters, conversely, must select one of six seven-day time periods in 12 permit areas, though if unsuccessful, they can also hunt the last two weeks of the season.

Though Kalahar owns a compound bow, he decided to try hunting with a crossbow.

"We can hunt the whole season, any zone, statewide," he said. "That's a real no-brainer for a guy like me who's addicted to turkey hunting."

Other hunters also embraced the changes. Last year, the number of archery permits sold to spring turkey hunters increased 105 percent to 10,343. Which means 20 percent of the nearly 50,000 spring permits issued last year were to hunters using compound bows or similar archery equipment, or crossbows.

The DNR doesn't track how many hunters use standard archery equipment and how many use crossbows, said Steve Merchant, DNR wildlife populations program manager.

But the popularity of archery hunting continues to grow. The DNR sold 107,000 archery permits to deer hunters in 2015, continuing an upward trend over the past 20 years.

"People like the flexibility of it for turkey hunting," Merchant said. "They can go when they want to go and not be confined to a seven-day period."

Still, bagging a bird with an arrow isn't a slam-dunk.

Hunters bagged 12,313 turkeys last spring, the second-highest total on record. Overall success rate was 25 percent, but just 14 percent of those with archery licenses got a bird.

No matter the style of bow used, an archer must get a bird close to take a shot.

"I like to try to get a bird with my crossbow at 20 yards," Kalahar said. "I'll go out to about 30, but beyond that I don't shoot."

Kalahar already has passed up turkeys this spring that were 40 yards away — in the killing zone for most shotguns.

"It's not about killing a turkey for me, it's about hunting.," he said. "The perfect season for me would be to shoot a bird on the 45th day. There's just nothing like being in the woods in the spring with the turkeys gobbling."

One reason legislators liberalized crossbow use was to encourage older hunters to continue to hunt. Kalahar says that makes sense.

"I still have my compound bow, but as you get older, they get harder to pull. I think crossbows are a good fit. Even if you aren't an avid archer, it's a weapon you can easily use. It doesn't take a lot of practice. It's like shooting a gun."

While we were in the blind last week, two gobblers emerged from the woods around 6:30 a.m. and sauntered across the field 100 yards distant. Both disappeared across the field.

Still, whenever Kalahar yelped, mimicking a hen turkey on his friction call, a nearby tom gobbled in response.

"Gosh, they are talking this morning," said Swenson, 55, of Cotton, Minn., who, using a shotgun, had dropped a 22-pound tom with a 10.5-inch beard the previous day.

An hour later, five birds walked out of the woods and headed straight for us. When they got closer, we identified them as jakes, or young male turkeys.

Strolling within 20 yards of Kalahar, they eventually sauntered away. We knew Kalahar wasn't interested in shooting a jake this early in the season.

By 9 a.m., the gobbling ceased, the sun burned off the morning fog and all was quiet. By 10:30 a.m., we pulled the plug, packed our gear and headed home.

"Well, that was a lot of gobbling, boys," Kalahar said. "It was a great morning. I can't wait to go to bed so I can get up and go again."

Doug Smith is a retired Star Tribune outdoors writer. Contact him at doug.smith23@charter.net.