![]() ![]() It will be issued as a series of chapters over the next several years, each with a unique number, designed to be inserted in an accompanying looseleaf binder. This product differs from most Fish and Wildlife Leaflets. The assistance of these reviewers, who included Federal and State wildlife managers, Federal and State biologists, and scientists in the United States and Canada, is most gratefully acknowledged. A prototype handbook was developed in 1987 and critiqued by 38 reviewers who provided suggestions on style and substance as well as topics for inclusion. Much of this information exists in scientific papers, unpublished reports, or has never been recorded, and thus is not readily accessible by waterfowl managers. The North American Waterfowl Management Plan, the Service's most recent mandate for management of migratory waterfowl, and recent legislation such as the Farm Bill all underscore the need for a single source of information about the management of waterfowl and their habitat. My presentation addresses disease as a factor suppressing waterfowl numbers and the relation of habitat quantity and quality with waterfowl disease. This is a tenable thesis if other factors suppressing waterfowl numbers are dealt with and the habitat base being enhanced sustains waterfowl rather than contributes to their death. A basic premise of the focus on wetlands is that restoration of waterfowl populations is habitat dependent. The importance of habitat loss also is reflected in many of the presentations at this conference on wetland conservation, including one special session devoted solely to that topic. Numerous joint ventures focusing on key waterfowl habitat requirements are being developed under the North American Waterfowl Plan. Loss of habitat is an accepted major cause for the decline of waterfowl numbers and the wildlife conservation community is responding with initiatives to prevent further loss of existing wetland acreage, restoration for degraded wetlands and creation of new wetlands. The decline of North American waterfowl resources since the 1960s is well-known to this audience and need not be detailed to establish that population numbers for several key waterfowl species are at or near their lowest levels since records have been kept. ![]() Various challenges exist to wetland management for invertebrates for waterfowl, but the lack of data on factors influencing production may be the most limiting.Įnvironmental influences on major waterfowl diseases Similarly, some terrestrial vertebrates (e.g., beaver (Castor canadensis)) may positively or negatively impact invertebrate communities in waterfowl habitats. Fish can compete with waterfowl for invertebrate forage in wetlands and harm aquatic macrophytes biomanipulation (e.g., stocking piscivores) may improve waterfowl habitat quality. Sparse study has been devoted to understanding the influence of waterfowl and wetland management on production of invertebrates for waterfowl foods however, manipulation of hydrology and soils may change or enhance production. Invertebrates are an important food for breeding, migrating, and wintering waterfowl. Invertebrates in managed waterfowl marshes ![]()
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