• Hunter, Malcolm L
  Division of Wildlife, College of Forest Resources, University of Maine, Orono, ME U.S.A. 04469
  
• Witham, Jack W.
  Division of Wildlife, College of Forest Resources, University of Maine, Orono, ME U.S.A. 04469
  
• Dow, Hillary
  Culterty Field Station, University of Aberdeen, Newburgh, Ellon, Aberdeenshire, Scotland AB4 0AA
  

In recent years the eastern spruce-fir forest has been heavily infested by spruce budworm Choristoneura fumiferana, (MacLean 1980). Control programs for the insect have involved aerially spraying millions of hectares with insecticides. Since the early 1970's the insecticides used have generally been short lived chemicals which are not know to be accurately toxic to vertebrate at normal dosages, but may be very toxic to aquatic invertebrates. Invertebrates constitute the major food for young ducks during the first 2-3 weeks after hatching. (sugden 1973; Swanson and Meyer 1973; Reinecke 1979) and there is potential for significant, although indirect, impact of spraying on duck broods.