Addressing the birds vs. new-Vikings-stadium controversy, a recent editorial in this newspaper touched on a wildlife management topic that might in the future entangle hunters — and non-hunters — more fully than it does today.

The stadium issue centers on whether its planned (huge) glass façade will endanger birds — perhaps songbirds, particularly — migrating along the Mississippi River, the arterial center of a flyway that is home to more birds than any other North American migratory route.

Audubon Society members and other bird enthusiasts want the Minnesota Sports Facilities Authority, owner and builder of the stadium, to kick in an extra $1.2 million to replace the structure's clear glass with a type of glass that birds can see better, and therefore avoid.

For now, the sports authority isn't budging, apparently believing that retaining the stadium's glassy architectural aesthetics outweigh the cost and (apparently) degraded appearance that would accompany requested changes, especially considering that only a nominal number of birds might be affected.

Whether this last is true, or perhaps lots of birds might be affected, no one really knows until the stadium is built.

But there's another, more philosophical side to this and similar debates, the gist of which is encapsulated in this sentence from the editorial: "… Individual bird deaths from collisions are almost meaningless as long as bird populations remain constant.''

The same approach, generally, has underpinned game management since its inception a century or more ago.

Consider waterfowl: State and federal biologists and managers base duck season lengths and harvest limits not on the number of mallards and other fowl hunters might kill in aggregate but on the number of these birds that return to the breeding grounds in spring.

Put another way, some ducks will perish while nesting or nurturing their young, or while flying south in fall — be it at the hands of a stadium (not likely for ducks) or a 12-gauge. But the means of these deaths, generally, don't matter to waterfowl managers, so long as the number of ducks killed by hunters is compensatory to (meaning, a part of) overall annual mortality, not in addition to it.

Of course, what is compensatory in a given year for an individual species, and what is additive, is often difficult to determine exactly. Thus the biologists' management fallback: Count ducks (via aerial surveys) that return to continental breeding grounds in spring, and worry less about harvest details.

Now consider a wrinkle:

What if, as some waterfowl managers have suggested recently regarding blue-winged teal — if only for discussion — so few hunters are afield nowadays that those who are could kill an unlimited number of these birds without harming the overall population?

In such cases, should individual hunters be allowed to take all they want? If not, why not? For that matter, why is the daily duck limit six and not four — or eight? And why not shoot ducks on the water, rather than on the wing?

Such questions aren't entirely hypothetical, and answers to them are generally favorable to many of today's hunters (and anglers), suggesting that a significant percentage of these enthusiasts have developed self-limiting, morally based behavior standards by which they conduct themselves in the field.

In the process — considering that many hunters and anglers also contribute to conservation groups — they have become, if only implicitly, net contributors to "the environment,'' rather than simply takers from it.

Which is good, because our fast-evolving society is becoming evermore demanding, and judgmental, of the ways that each of us, individually and collectively, interacts with natural resources.

Some of this can be dismissed as post-modern hogwash, a complete misunderstanding of how the natural world works and our effects on it.

But rejecting outright the sincere concern over sustainability, broadly defined, that is fast gaining a foothold in America, especially among young people, would be a mistake.

A century ago, it was socially acceptable to use a punt gun to kill hundreds of ducks in a single shot. Now it's not.

A few decades ago, it was socially acceptable to dispose of drink cans by tossing them from car windows, into ditches. Now it's not.

Today, it's still socially acceptable to build a glass stadium that might or might not threaten individual birds, or their populations.

Enjoy it while you can.

Because times — and people — are changing.

Dennis Anderson • danderson@startribune.com