USGS Home
Contact USGS
Search USGS

BELL, J. F., G. W. SCIPLE, and A. A. HUBERT. 1955. A microenvironment concept 
     of the epizootiology of avian botulism. J. Wildl. Manage. 19:352-357.

COTTAM, C. 1939. Food habits of North American diving ducks. U.S. Dep. Agric. 
     Bull. 643. 140pp.

DOWNING, J. A. 1979. Aggregation, transformation, and the design of benthos 
     sampling programs. J. Fish. Res. Board Can. 36:1454-1463.

DUNCAN, R. M., and W. I. JENSEN. 1976. A relationship between avian carcasses 
     and living invertebrates in the epizootiology of avian botulism. J. Wildl. 
     Dis. 12:116-126.

ELLIOTT, J. M. 1977. Some methods for the statistical analysis of samples of 
     benthic invertebrates. Freshwater Biol. Assoc. Sci. Publ. No. 25. 159pp.

EULISS, N. H., JR., and S. W. HARRIS. 1987. Feeding ecology of northern 
     pintails and green-winged teal wintering in California. J. Wildl. Manage. 
     51:724-732.

_____, and G. A. SWANSON. 1989. Improved self-cleaning screen for processing 
     benthic samples. Calif. Fish and Game 75:126-128.

GRUE, C. E., M. W. TOME, T. A. MESSMER, D. B. HENRY, G. A. SWANSON, and L. R. 
     DEWEESE. 1989. Agricultural chemicals and prairie pothole wetlands: 
     meeting the needs of the resource and the farmer-U.S. perspective. Trans. 
     North Am. Wildl. Nat. Resour. Conf. 54:43-58.

JENSEN, W. I., and J. P. ALLEN. 1960. A possible relationship between aquatic 
     invertebrates and avian botulism. Trans. North Am. Wildl. Nat. Resour. 
     Conf. 25:171-181.

MARTIN, A. C., and F. M. UHLER. 1939. Food of game ducks in the United States 
     and Canada. U.S. Dep. Agric. Bull. 634. 157pp.

MERRITT, R. W., and K. W. CUMMINS. 1984. An introduction to the aquatic insects
     of North America. Second ed. Kendall-Hunt Publ. Co., Dubuque, Ia. 441pp.

REINECKE, K. J., and R. B. OWEN, JR. 1980. Food use and nutrition of black 
     ducks nesting in Maine. J. Wildl. Manage. 44:549-558.

RESH, V. H. 1979. Sampling variability and life history features: basic 
     considerations in the design of aquatic insect studies. J. Fish. Res. 
     Board Can. 36:290-311.

SWANSON, G. A. 1978a. A water column sampler for invertebrates in shallow 
     wetlands. J. Wildl. Manage. 42:670-672.

_____. 1978b. Funnel trap for collecting littoral aquatic invertebrates. 
     Prog. Fish-Cult. 40:73.

_____. 1978c. A simple lightweight core sampler for quantitating waterfowl 
     foods. J. Wildl. Manage. 42:426-428.

_____. 1983. Benthic sampling for waterfowl foods in emergent vegetation. 
     J. Wildl. Manage. 47:821-823.

_____, and J. C. BARTONEK. 1970. Bias associated with food analysis in 
     gizzards of blue-winged teal. J. Wildl. Manage. 34:739-746 

_____, G. L. KRAPU, and J. R. SERIE. 1979. Foods of laying female dabbling 
     ducks on the breeding grounds. Pages 47-57 in T. A. Bookhout, ed. 
     Waterfowl and wetlands - an integrated review. Proc. Symp. North Cent. 
     Sect., The Wildl. Soc. Madison, Wis.

WARD, H. B., and G. C. WHIPPLE. 1959. Freshwater biology. Second ed. John Wiley
     and Sons, New York, N.Y. 1248pp.