We examined the use of Lake Christina, Minnesota, USA, by nongame waterbirds following an autumn 2003 application of rotenone to eliminate its fish base and enhance migrating canvasback (Aythya valisineria) habitat. The only nongame waterbirds observed attempting to nest in 2004 were black terns (Chlidonias niger), but they failed to hatch any young. We recorded 246 Western grebes (Aechmophorus occidentalis) on Lake Christina in the spring of 2004, but by mid-June most had left the lake. During this period, few fish were available, and we suggest that although the emergent vegetation was suitable for nesting, the lack of food prevented colony formation. In spring 2005, small fish were again available on the lake, and numbers of all nongame species were greater than in 2004. We located 315 western grebe nests, of which 198 hatched ≥1 young (63% of all attempts). Landscape-level manipulation may enhance habitat for some species but also has the potential to exclude trophic levels from future use and should be considered when manipulating large-scale systems.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 71 • No. 4