While young Minnesotans appear to increase their interest in pursuing deer and small game during their initial years in the field, the same hunters in significant numbers drop out of waterfowling, according to recent Department of Natural Resources license data reviewed by the Star Tribune.

In a comparison of small-game and deer-hunting license sales with sales of waterfowl stamps over an eight-year period beginning in 2003, young hunters slightly increased their interest in small-game hunting and nearly doubled their participation in deer hunting, according to the DNR data.

Yet license sales to young waterfowl hunters as they aged through the period dropped by nearly 20 percent.

License sales to Minnesota waterfowl hunters have been at or near record lows in recent years, and wildlife managers have struggled to rekindle interest in the sport amid declining duck numbers.

Traditionally, Minnesota has put more duck and goose hunters in the field than any state -- more than 125,000 at one time, compared to about 70,000 now.

In the newspaper's study, significant percentages of middle-age and older waterfowlers whose license purchases also were tracked between 2003 and 2010 dropped out of duck and goose hunting by the end of that period.

Yet as the years progressed, both age groups increased deer-hunting license purchases, and only the older set -- age 58-65 -- bought fewer small-game licenses.

A separate study released Friday by the DNR at its stakeholders meeting in St. Paul suggests that as many as 60 percent of waterfowlers who have dropped out of duck and goose hunting are unlikely to return to the sport unless a son, daughter or other family member shows an interest, or unless duck numbers jump significantly.

The percentage of waterfowlers unlikely to return to the sport might be even higher for young duck and goose hunters who drop out, because they haven't yet fully developed wildfowling traditions.

License sales tracked by the newspaper found that the number of Minnesota hunters who were at age 40 and purchased small-game licenses in 2003 -- 4,615 in all -- didn't decline as that group reached age 47 in 2010.

The same age group increased its deer-hunting license purchases by 10 percent.

Yet about 20 percent fewer of these middle-age hunters purchased state duck stamps when their group was age 47 than when it was age 40.

Hunters who were 58 in 2003 and who bought deer-hunting licenses that year also boosted their ranks by 2010 -- 4,511 to 4,786.

Yet waterfowl-license purchases among that group fell by about a third.

Combined with the DNR's study of lapsed waterfowl hunters, the prospect that the state might see a recovery in waterfowl hunter numbers anytime soon seems, at best, uncertain.