Doug Leier column: Wildlife population needs all the right ingredients to be successful

Building and maintaining healthy fish and wildlife populations is in some ways similar to establishing a successful football team.

You may raise your brow and wonder how fish and fowl compare to football, but take my beloved Minnesota Vikings for example. Even with stars like Randy Moss and Daunte Culpepper, the team can struggle to maintain success if key ingredients are missing.

Wildlife population shifts can follow the same pattern as the won-loss record of your favorite football team from season to season, depending on weather and habitat conditions. If one or more ingredients is missing, regardless of how good the others are, the following hunting season won't be as good as the years when all factors are in peak condition.

All wildlife populations depend on habitat -- food, water, shelter and space. It's obvious that no animal can survive without food, but over time a lack of shelter or space is just as detrimental.

One example is the current mid-continent snow goose population. This population is so high that overcrowding on arctic nesting grounds is threatening long-term health of the species. It's a case of too many animals for the available space.

For many animals, overcrowding leads to increased competition for food and a greater potential for disease transmission. In the worst cases, the end result can be death by starvation or sickness.

People like to have abundant wildlife, but problems are likely when a population grows beyond what available habitat can support.

The same can hold true for football, when star players compete for time on the field. Team success is often compromised when players are unhappy with their amount of playing time.

Upland game birds

Hunters understand that a harsh North Dakota blizzard can decimate a pheasant population. The extreme stress put on wildlife during the winter of 1996-97 was felt for a number of years, and serves as a contemporary reminder of the importance of shelter in the habitat equation.

Even if pheasants could find food, that was not always enough to save birds from succumbing to exposure due to lack of suitable winter cover.

The necessity of all habitat elements becomes apparent each spring and summer. Cool, wet weather during June affects upland game birds reproduction success. Young pheasant, grouse and partridge chicks are unable to regulate their own body temperature for several days after they hatch.

During that critical time, cool wet days can cause significant losses. Back to my football analogy. While the star quarterback injuring a knee may generate headlines (like winter blizzards that wipe out thousands of pheasants) and lead to a poor season, losing a reliable lineman can yield similar results without as much fanfare.

For North Dakota's upland game birds, winter weather usually grabs the headlines, but June weather is probably just as important, since the fall population is usually 50 percent or more young-of-the-year birds.

If June weather is cold and wet, or hot and dry, it can mean reduced success in the fall even if spring adult bird numbers are high.

Waterfowl

Migratory waterfowl do not endure harsh North Dakota winters, consequently, significant population shifts from one year to the next are not as likely as would be for pheasants.

Waterfowl populations rise and fall more gradually, like a young football team eventually developing into a contender. As long as the main habitat ingredients are in place, waterfowl populations can grow and prosper.

One of the key factors for ducks is small, temporary wetlands. North Dakota has tens of thousands of these shallow basins that typically collect water from spring snow melt or rain but may dry up by summer's end.

Ducks find food in these temporary wetlands, and also use them for breeding territories. Duck production is diminished when many temporary wetlands are dry in spring, as was the case this year after a winter with little snowfall and a dry April and May.

While recent significant rain in parts of the state likely recharged many small wetlands, for ducks it may be a little late for this year. For upland game birds, early June rains fell before peak hatch dates; chick survival will depend moreso on weather over the next three weeks.

As with football and its preseason games, we can make some guesses as to how our "team" will do this fall, based on current habitat and weather factors.

But we'll have to wait until the real season starts to determine if our preseason forecasts come true.

Leier, an outreach biologist for the North Dakota Game and Fish Department in West Fargo, can be reached at (701) 277-0719 or at dleier@state.nd.us