A Most Unusual Season

Biologists' observations on the 2001-2002 waterfowl migration
By Keith McKnight, Ph.D.
This past fall and winter, waterfowlers in many areas across North America witnessed the strangest and, for some, the most frustrating hunting season in memory. Coming on the heels of a 2000-2001 season that was one of the better hunting periods for many duck hunters in a long time, the most common question this past season was: "Where were all the ducks?" Biologists across the continent had warned us of a somewhat reduced fall flight, but that certainly is not an adequate explanation for what occurred during this past duck season. While there is no single answer for every case and every location, a look at what we do know sheds some light on the important interplay of weather and waterfowl behavior.

If you ask a group of people why ducks go south for the winter, the majority will respond "because it is cold up north." However, that is only part of the answer. Ultimately, ducks fly south during winter when the availability of food, relative to their energy needs, is inadequate. The natural pattern is for temperatures to turn progressively colder through fall and winter, with an associated increase in snowfall and ice cover at northern latitudes. Sustained cold weather turns open water into ice and increases the energy needs of waterfowl, while accumulation of snow covers waste grain.

As long as there is plenty of food and some open water, however, ducks (especially mallards and scaup) have little reason to migrate farther south. Even extreme cold snaps of up to a week in length are often not enough to send a healthy mallard on its way. In fact, one of these factors alone (open water or available waste grain) is enough to postpone or even cancel southerly flight plans. This year, much of the country saw both record warm temperatures and low snowfall. The result was an odd distribution of ducks that left many waterfowl hunters scratching their heads.

Mild weather in Massachusetts also spawned predictable results. Midwinter duck numbers appeared to be good, with a preponderance of ducks in the north. "In hard winters, we see few birds north of Boston, with many more around Cape Cod and south. This year we saw large numbers of black ducks and other species in the northern portion of the state in mid-January," says H.W. Heusmann of the Massachusetts Division of Fisheries and Wildlife. Hunting for wood ducks and mallards was also good in inland areas of the state. Sportsmen witnessed a rarity for New England this season, according to Heusmann. Flocks of green-winged teal were encountered in many places throughout the duck season. Lack of harsh winter weather apparently allowed these birds to remain far north of their usual wintering areas.

Dry conditions in New Jersey through summer and fall had a negative impact on food production in coastal marshes. "Pools and ponds that normally provide widgeongrass and salt grass seed just didn't have the groceries," says Paul Castelli of the New Jersey Division of Fish and Wildlife. So, although midwinter waterfowl numbers were about normal, birds could not be found in their typical haunts. As Castelli explains, "We had a double-whammy at Forsythe National Wildlife Refuge (NWR). The big impoundments held tens of thousands of puddle ducks, but there were few ponds off the refuge that provided much food. Add the mild weather to that mix, and hunting was boom or bust."

The late, mild winter had predictable effects on duck movement farther down the flyway in the Mid-Atlantic region. Numbers of ducks in Maryland, Virginia, and North Carolina typically build from November into December. However, this year the ducks didn't show up in any number until after the holidays, and according to Gary Costanzo of the Virginia Department of Game and Inland Fisheries, "not in as great a number as there should have been." On top of that, Costanzo adds, "Conditions were too mild to force the birds to move around." This scenario was amplified farther south along the Atlantic. As summarized by Tommy Strange of the South Carolina Department of Natural Resources, "Our midwinter [waterfowl] counts were down substantially this year. But with such a warm winter, it's no surprise that birds were somewhere to the north of us." There was at least one positive note for the midcoast, however. Canada geese provided a real bright spot for some Mid-Atlantic states. Virginia hunters saw good numbers of Atlantic Population Canada geese, providing for a relatively satisfying goose season.

The story was much the same in Louisiana. The south Louisiana midwinter survey recorded about 1 million fewer ducks than the five-year average. With midcontinent breeding populations of most duck species down, but above the long-term average, hunters in the South were searching for answers.

The disappointing season in Arkansas doesn't help much in explaining where Texas' and Louisiana's birds were. Preliminary indications from waterfowl surveys suggest that ducks certainly were not "stacked up" in Arkansas. In addition, extremely wet conditions helped ensure that the ducks had plenty of places to avoid pressure. "Ducks were spread everywhere in small bunches of 50 to 100," remarks Mike Checkett, waterfowl biologist for the Arkansas Game and Fish Commission. "There was a lot of water, so when ducks were hunted they could easily find places to sit where they weren't shot at." On top of that, warm temperatures made it less necessary for these ducks to move around. Checkett sums up the season, "The ducks were scattered and relatively stationary, basking in the Indian summer conditions."

Weather conditions through fall and early winter in Missouri were similar to other states in the region, with open water available later than usual. However, Missouri was extremely dry, with habitat limited to state and federal management areas, duck clubs, and a few Wetland Reserve Program sites, according to Dale Humburg, wildlife research biologist for the Missouri Department of Conservation. "Dry conditions concentrated large numbers of birds on limited habitat," explains Humburg. Many hunters were somewhat frustrated with the odd conditions. According to Humburg, "Historically, Missouri receives consistent pushes of birds at biweekly periods. This year there were long lulls between substantial migrations of birds into the state." The midwinter count of half a million birds, while higher than the 2001 count, was well within the long-term range [85,700-714,000].

The weather seemed to bring mixed blessings in Illinois. With a full 60 days of hunting (compared to 30 or less in the harsh freeze-out winter of 2000-2001), duck harvest on state areas was up 49 percent in 2001-2002, according to Ray Marshalla, state waterfowl biologist for the Illinois Department of Natural Resources. "We set harvest records on some important state waterfowl hunting sites this year, such as Carlyle Lake." Peak duck numbers for the state occurred on January 7, compared to mid-November, as is normal. While the midwinter index recorded almost two times the number of ducks this year versus last, only half the Canada Geese were recorded. In the southern Illinois quota zone, the peak count was 100,000 geese fewer than the previous record low in 1985. And according to Marshalla, "Although there were more geese in the north and central zones, hunting was generally very slow due to mild weather and the occurrence of many geese on golf courses and lawns."

Across the Mississippi into Iowa, we find more evidence of where those midwinter ducks were hiding. Guy Zenner, waterfowl research biologist for the Iowa Department of Natural Resources, relates that with the warmest November in 129 years, and a December nearly eight degrees above normal, duck counts were the second-highest on record. "This year, almost everybody was hunting open water through the last day of the season on December 6. Since I came to northern Iowa in the late 1970s, I can remember only three seasons in which we could hunt through the end of the duck season." As an example, Clear Lake in northern Iowa posted the latest freeze-up on record (Christmas Eve). "On a typical Christmas Eve, people are driving out on the ice to go ice fishing," says Zenner.

To the west, both Nebraska and Kansas experienced extremely mild temperatures and no snow cover, providing waterfowl open water and abundant food throughout the season. However, Kansas was very dry, especially in the east and southeast, and according to Marvin Kraft, waterfowl project leader for the Kansas Department of Wildlife and Parks, "Mallards never showed up in the eastern portion of the state." On the other hand, midwinter counts in Nebraska indicated greater overall populations of ducks, especially mallards. In addition, Mark Vrtiska, waterfowl biologist for the Nebraska Game and Parks Commission, reports "Southern Nebraska had good numbers of mallards late on five- to 20-acre lakes that are not typically surveyed during the midwinter counts."

The Dakotas and Minnesota experienced excellent waterfowl seasons. South Dakota in particular saw extremely mild temperatures and no real snow cover until late November. "Indications are that this was the best waterfowl and mallard season in 30 years for South Dakota," says Spencer Vaa, migratory bird biologist for the South Dakota Game, Fish and Parks Department. "South Dakota had a lot of waterfowl, and these populations were sustained until the late November blizzard." Historically, South Dakota freezes up by the first week in November. Minnesota also posted record high temperatures and a record late freeze-up. In fact, hunters at Thief Lake in northwest Minnesota were able to hunt 59 of 60 days - an extreme rarity. "Mallard shooting was excellent well into November," reports Jeff Lawrence, waterfowl staff specialist for the Minnesota Department of Natural Resources. "There were good numbers of birds and lots of opportunities."

Open water as far north as Michigan's Upper Peninsula and portions of southern Canada in December and even in January, coupled with readily available waste grain in fields that are normally blanketed in snow, served up a season to remember in many northern states, and a season they'd like to forget across the South.

Some areas in California fared well. Harvest at Gray Lodge State Wildlife Area, for example, was up from 2000-2001, according to Mike Womack, wildlife area manager with the California Fish and Game Department. However, local conditions that are conducive to good hunting, such as heavy fog, just didn't occur very often throughout the Valley. "December was poor, but the January success bolstered the season totals," says Womack. The Suisun Marsh and West Delta may not have experienced a similar upswing, and there were certainly individual clubs throughout the state that did not rebound in January, but California should account for 45-50 percent of all ducks harvested in the Pacific Flyway, as has been the historical pattern.

Lingering effects of the prolonged drought reduced available habitat in some portions of the flyway, such as south-central Oregon. The Klamath Basin was particularly hard hit by drought, with only a little relief in time for fall flood-up. Dave Mauser, U.S. Fish and Wildlife Service wildlife biologist for the Klamath Basin refuges, reports that wetland habitat was only at about 50 percent of what it should have been, due to lack of water. Accordingly, peak bird numbers were about half of the 1990s average, with much of the reduction felt at Lower Klamath National Wildlife Refuge (NWR). As Mauser explains, "Hunting opportunity around the basin was reduced as a result of the shortage in wetland habitat."

Western Oregon also saw below average numbers of ducks and geese. "The Willamette Valley, in particular, had plenty of water," reports Brad Bales, game bird biologist with the Oregon Department of Fish and Wildlife, "but there just weren't a lot of birds." Fortunately, areas in eastern Washington and Oregon saw a late influx of ducks. According to Bales, "The Snake River and upper Columbia River experienced a marked increase in puddle ducks during the last three to four weeks of the season."

Waterfowlers in the Great Salt Lake marshes generally experienced a below-average season, according to Tom Aldrich, waterfowl program coordinator for the Utah State Division of Wildlife Resources. "For the most part, we didn't have the traditional build-up of birds through the season. The north end of the lake experienced one of the driest years ever, which reduced habitat availability, particularly around Bear River NWR. In wet years, water tops spillways at the refuge and floods state-owned lands that can hold a lot of birds," explains Aldrich. "This year we just didn't get the water for that." Lower than normal swan abundance was also largely attributable to the dry conditions at Bear River NWR.

Overview
In general, unseasonably warm and snow-free weather in the northern latitude states, especially east of the Rockies, made it possible for birds to linger father north this year. In addition, unusual moisture patterns created drought in some areas and abundant water in others, resulting in either a scarcity of birds (no wetlands) or a dispersion of birds (a few birds on a lot of wetlands)--both of which made for challenging hunting. It is safe to say that this past season held many surprises for sportsmen across the country - some good, some bad.

Regardless of how many ducks flew near us this season, though, our resolve should be to ensure the habitat is there in years to come. As was well stated by Ken Babcock, director of DU's Southern Regional Office, "We need to stay focused on the most important issue for waterfowl, and that's habitat conservation. Our best hope for healthy waterfowl populations tomorrow is to work together to conserve their habitat today." And as we move into another nesting season, that's exactly what DU is going to do.