Double-crested Cormorants in the Midwest: symposium summary

TitleDouble-crested Cormorants in the Midwest: symposium summary
Publication TypeConference Proceedings
Year of Conference1999
AuthorsCuthbert FJean
Conference NameProceedings of the 1997 Symposium on Double-Crested Cormorants: Population Status and Management Issues in the Midwest
PublisherNational Wildlife Research Center, United State Department of Agriculture

An important contribution to this symposium was the conclusion by Trapp and colleagues that scientific evidence does not support the contention that cormorants significantly affect sport-fish populations or angler catch. Additionally, agency responses to their survey expressed mixed opinions about cormorant control, and no States provided evidence that increased cormorant populations have affected local economies associated with sport fishing or tourism. Furthermore, no States surveyed have developed public education material on cormorants and the problems they cause. The latter is clearly needed. The Canadian Wildlife Service has produced a Great Lakes Fact Sheet: "The Rise of the Double-Crested Cormorant on the Great Lakes: Winning the War against Contaminants" (Weseloh and Collier 1995), which serves as an excellent example of public education available on this species in Ontario. The link between the breeding colonies and wintering areas is vital to understanding population increases in both areas. More information is needed on winter ecology and how it affects the life history of breeding birds. Do cormorants that feed at aquaculture facilities have higher survival, breed earlier, and/or produce more offspring than those that winter in areas remote from catfish farms? As Bedard and colleagues pointed out, many problems of over-abundant wildlife are lurking on the horizon and complex philosophical issues affect control decisions. This symposium was organized to examine issues related to control of cormorants in the Midwest and ended with general consensus that more data are needed to justify regionwide control efforts. At present, cormorant human conflicts in the Midwest appear best addressed at the local level on an individual case basis.