A Review of Predation Management for Wetland Birds
in North America
ERIK K. FRITZELL
School of Natural Resources, University of Missouri, 112 Stephens
Hall, Columbia, MO 65211
Predation management is the purposeful manipulation of predation rate to achieve specific wildlife management objectives. Management techniques involve modifying habitat (including artificial structures), indirectly and directly manipulating predator populations or behavior, and influencing people. A history of ideas relating to predation management in North America, emphasizing wetland bird production, is presented. Technical and popular literature of the last century depicts three dimensions to the topic: ecological, economic, and ethical. As knowledge of predator-prey dynamics changed, so did attitudes of professionals and the public. Widespread predator control to protect "beneficial" species in the first half of the 20th century changed to a retreat from the practice by the 1970s. Increasingly refined knowledge of wildlife ecology coupled with increasing human demands from a limited resource base have resurrected the potential for predation management to enhance populations of desired wildlife. The public, however, may not yet accept some forms of predation management. Their doubts may reflect disagreement with management goals more than specific practices. For example, predator control to protect endangered species has seldom been questioned, yet control for game production remains controversial. Interestingly, the post-1930's recognition of "balance" among many predator-prey systems was not accepted by leading scientists when considering predator-waterfowl relationships. Observed predation rates on breeding ducks often did not conform to hypotheses and dogma generated from other predator-prey systems. Seasonal abundance of migratory birds in human-altered wetland landscapes may promote high vulnerability. Greater knowledge of predator-prey relationships and refinement of predation management practices should promote confidence for decision-making. Acceptance by a diverse public will influence further development of predation management practices in the future.
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