IN NORTHERN MINNESOTA — A throwback of sorts, Dallas Hudson makes his own bows and arrows, takes long walks in the woods carrying a notebook and isn't averse, as on this evening, to forgo an outboard motor for a pair of oars.

Saying we would be fishing for crappies would be accurate but not completely so. There would be some of that, but also a lot of hot air expended about angle-wings and mourning cloaks, and of course monarchs — butterflies that Dallas, as a phenologist, counted this spring and summer.

Also, we would chat about bear and wolf numbers in this part of northern Minnesota (both are up), deer numbers (down dramatically, said Dallas), and whether jewelweed, woodland sunflowers and asters had bloomed yet, signaling fall's onset.

All of this would transpire on a windless evening beneath cobalt skies and pillowlike clouds whose mirror images shimmered on the glassy lake as Dallas' tin boat sliced them in half, and half again.

"You want to keep some tonight?''

"Keep a meal,'' I said.

Being a Minnesotan means different things to different people. Where Dallas grew up, hard by the shores of Eleventh Crow Wing Lake in Hubbard County, it meant running a trap line in winter before school, beginning in third grade.

A lesser boy would have nodded off while his teacher yodeled sonorously about the importance of multiplication tables. But Dallas was keen to learn what a dozen muskrats could earn him at $5 apiece, so he paid attention.

I fooled the first crappie, an 11-incher. Using no bait, we deployed instead Mr. Twisters affixed to tiny jigs. Cast to a weed line and retrieved slowly, they kept us busy enough, picking and choosing specimens we kept and those we returned to the lake.

In a way, we were cheating. This was a limited-access lake that sees few anglers. Having experienced firsthand what over-harvest can do to a fishery, Dallas likes it that way.

"When I was a kid, my friends and I speared northern pike on this lake until they were all gone, or almost all gone,'' he said. "I was part of the problem. But no more.''

After 25 years with the U.S. Department of the Interior — 10 with the U.S. Fish and Wildlife Service and the remainder with the U.S. Geological Survey — Dallas retired last year.

Yet he hasn't stopped doing for fun what he once did for work: counting things. If not butterflies, then dragonflies, wild turkeys, foxes, coyotes, hawks, owls, acorns and all manner of berries, including blueberries, raspberries, blackberries and chokeberries.

It's what a phenologist does: monitor changes to plants, fish and wildlife in relation to climate, weather and other variables.

Northern pike, in particular, fascinate Dallas, in part because he believes Minnesota anglers underappreciate them as game fish, and in part because he believes northerns are mismanaged by the Department of Natural Resources (DNR).

More accurately, he believes northern pike anglers are mismanaged by the DNR.

"The few really big pike that remain in northeast Minnesota, for example, those over 40 inches, should be catch-and-release only,'' he said. "And in northern-central Minnesota, where you can keep two northern pike over 26 inches, they should knock that limit down to one. Better yet, these bigger northerns should be managed like lake sturgeon. Anglers should get two or three tags a year to keep these fish, and that's it.''

In 2018, the DNR enacted a three-part northern pike management scheme that divides the state into south, north-central and northeast regions. The goal, generally, is to reduce the number of "hammer handle'' pike — the 18- and 20-inchers — that proliferate in so many state waters.

"What the DNR did was increase the northern pike limit in north-central Minnesota to 10, with two allowed over 26 inches and the rest must be under 22 inches,'' Dallas said. "What that does is target too many northerns over 26 inches, while taking the most aggressive individuals out of the smaller northern-pike population. Those are the fish that eat the most and have the best chance to grow to 26 inches and longer.''

To satisfy his curiosity about Esox lucius, Dallas caught by hook and line, and by net, about 80% of the northern pike in his 160-acre lake. With the DNR's permission, he measured, weighed, sexed, and tagged each fish over about eight years.

All northerns are aggressive and opportunistic feeders, Dallas learned. But certain individuals are more so.

"We could identify each fish by its tag, and sometimes we caught the same fish by hook and line twice in an outing,'' Dallas said. "I believe these extra-aggressive northerns are the same ones under 22 inches that are most likely to be caught and kept in the DNR's 10-northern limit, reducing the chance they'll grow to more than 26 inches and larger, which are the sizes we all want more of.''

Bethany Bethke, a DNR research scientist stationed in Duluth, monitors the agency's northern pike regulation changes. It's too early to tell what effect, if any, the new program is having, she said.

Yet the effort is important, she said, not only for how it might improve northern pike sizes but because northerns interact in critical ways with other fish, including yellow perch and walleyes, both of which are forage for northerns.

"Studies have shown, for example, that walleye stocking is less successful in lakes with large northern pike populations,'' Bethke said.

The other evening, Dallas and I mused about these matters and others.

"The bottom line,'' he said, "is that in too many instances too many people are putting too much pressure on fish, in some cases reducing sizes. This is true for sunfish and crappies, in addition to northerns, and by cutting the sunfish and crappie limits, the DNR is doing the right thing. With northerns, the issue, in my opinion, is more complex.''

As darkness gathered over the lake, I pitched my fake bait one more time.

"Last cast,'' I said.

Minutes later, rowing to shore, Dallas considered what he might see the next day when he walked in the nearby woods, notebook in hand.

"I heard a tremendous amount of grouse drumming this spring,'' he said. "But I haven't counted a single brood.''

Correction: Angle-wing and mourning cloak butterflies were misspelled in an earlier version of this story.