By Tina Yerkes, Ph.D.
Upon arriving in the prairie pothole country in early spring, pintails find a cold and often frozen landscape. To pintails, the spring thaw can provide a virtual paradise of spring wetlands, or a dry, barren desert.
The Prairie Pothole Region is recognized as the duck factory of the world, and for good reason. Before European settlement, it was a vast and beautiful country dotted with more than 20 million acres of wetlands supporting unbelievable numbers of breeding ducks. Today, pothole country is still the most amazing place in the world for a waterfowl lover, but it has fewer wetlands than it once did, especially the shallow spring wetlands that pintails love.
Shallow spring wetlands, technically called ephemeral or temporary wetlands, are shallow depressions in the prairie landscape. Because they are shallow, they warm with the first hint of spring and melt before all others. They also trap melting snow and runoff. These wetlands are critical for attracting early-arriving ducks to settle in an area and are very important food sources. Duck pair densities are associated with the number of spring wetlands: More wetlands mean more duck pairs that settle in the area.
But not all spring wetlands are the same: Some are deep and will hold water throughout the year, while some are very shallow and will hold water for only a month or two. It is the shallow ephemeral and temporary wetlands that are the most important to pintails, and these are the first to be adversely affected by drought and farming practices (they are easier to drain and can often be cropped during dry years).
Pintails have a love-hate relationship with spring wetlands. Historically, pintail numbers tracked wetland numbers very well in the prairies. When the prairies were wet, in prime condition, and covered with spring wetlands, pintail numbers were high. But, when drier times occurred and fewer spring wetlands existed, pintail numbers were low. This pattern is due to the unique nature of pintails: Their numbers can boom when conditions are right. Pintails have several characteristics that set them apart from other ducks.
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They have the ability to "get in and get out." That is, they are the first duck to arrive and nest in the spring; they lay fewer and smaller eggs, incubate for a shorter period, and have the shortest brood-rearing period. All this allows a hen pintail to produce ducklings in about nine weeks, compared to about 11 weeks needed by a mallard hen.
The best pintail years are those with the wettest springs. In these years, pintails can be found in great numbers on the prairies and experience good production. However, if the prairies are dry, they move on to greener (or wetter) pastures. This will result in fewer birds settling in the Prairie Pothole Region. Because pintails don't home as strongly as other ducks (see "Homeward Bound" in the March/April 2001 issue), they can respond to drought conditions by searching farther north.