Moto-duck, an effective new mechanical decoy, is causing a flap this season among California duck hunters and environmentalists-prompting a team of UC Davis wildlife biology researchers to study its impact. John Eadie, a professor of wildlife, fish and conservation biology, is leading the study of the device's effect on duck response, hunter success, seasonal effects, extent of use and effect on harvest. The hunting aid consists of a motorized revolving disk-one side painted white, the other brown or black-that produces a strobe effect that may mimic the flashing wings of landing ducks. Placed among more traditional decoys, it is said by some to lure ducks in droves, significantly increasing numbers of ducks bagged and potentially altering bird behavior and increasing the state's duck harvest. Hunters began using moto-duck last year, and by this year, it became very popular. Just how lethal is moto-duck? "It clearly can be an effective decoy, but we really don't know if it has any impact whatsoever on California's waterfowl populations," said John Eadie, a professor of wildlife, fish and conservation biology who is leading a study of moto-duck's effect on duck response, hunter success, seasonal effects, extent of use and effect on harvest. In the worst-case scenario, if the device is effective -- altering bird behavior and increasing the harvest -- it could add to the total harvest of waterfowl and that would be undesirable, "but we're just beginning to examine the possible impacts," Eadie said. Environmentally, the device could detract from habitat conservation efforts, particularly those among the duck- hunting community. "There's some concern that making hunting more successful in marginal habitats could reduce interest in developing good habitat," Eadie said. "But, on the other hand, it could drive up interest in waterfowl hunting and recreation, which would ultimately provide more funds-through sales of game licenses and duck stamps-for wetland management and conservation." The issues raised by the moto-duck controversy extend to social and ethical considerations -- even, Eadie says, the question of whether hunters are 'hunting or shopping'. "It is a revealing debate. Although the device is remarkably simple, it has opened many of the undercurrents involved in wildlife management." Eadie and his team will conclude the data collection when duck-hunting season ends later this month, and spend the spring analyzing the findings.