control was reported in New Brunswick (Pearce et al. 1976; and Erskine 1978). 

 Declines in the population of small, high canopy feeding passerines in sprayed 

 areas were reported in 1975. 



The major agricultural spraying program in coastal Maine is for control of the 

 blueberry maggot (see atlas map 2 for the distribution of blueberry barrens). 

 Guthion has been used since 1969 for the control of this pest. Prior to that, 

 DDT and sodium arsenate compounds were used. Guthion is considered more 

 toxic than chemicals used on spruce budworm. Three bird species (marsh hawks, 

 vesper sparrows, and upland sandpipers) currently considered declining on a 

 regional basis by the National Audubon Society (Arbib 1979), nest or feed in 

 blueberry barrens sprayed with Guthion. The vesper sparrow began declining in 

 eastern Maine during the 1940s (Bond 1947). The relationship between the 

 declining populations of these species, blueberry field management techniques, 

 and Guthion needs evaluation. 



In addition to direct toxicity, insect control programs deprive birds of food 

 during the breeding season, a time when nearly all terrestrial birds in 

 coniferous forests are insectivorous. Most of these feed in the canopy where 

 food loss from insect control programs is greatest. Outer canopy feeders 

 (middle and upper canopy species) are most affected, while bark drillers, bark 

 gleaners, ground feeders, and shrub feeders are less affected. 



Although the subject has not been studied extensively, evidence suggests 

 changes in behavior and reproductive success may be related to changes in food 

 supply. For example, a recent study evaluating the effects of Sevin on birds 

 reported a steady decrease in canopy feeders for 8 weeks following spraying 

 (Moulding 1976). The decrease was the result of birds moving into nearby 

 unsprayed areas where food was more accessible. These trends are similar to 

 those reported for the insecticides Dylox (Chambers 1972; and Caslick and 

 Cutright 1973), Orthene, and Matacil (Pearce 1970; and Moulding 1976). In the 

 above studies a 12% to 16% decline in numbers was reported 2 to 3 weeks 

 following field applications of the pesticides. Moulding' s study extended to 

 8 weeks after spraying, at which time a 45% decline in bird numbers was 

 reported. He concluded, "...nesting failure with concurrent food stress might 

 lead to a breakdown in further nesting behavior or a shift toward unsprayed 

 habitats for renesting later in the season, with a resulting site loyalty 

 shift expressed the following year." The nestlings of birds flying longer 

 distances to gather food in unsprayed areas could have reduced growth rates or 

 reduced fledging success. 



Accidental mortality . An estimated 62 million birds die annually in the 

 U. S. as a result of collisions with automobiles and human-made structures 

 (Banks 1979). An estimated 297 of human-induced mortality results from road 

 kills. The most common victims are song sparrows, robins, house sparrows, 

 small owls, and pine grosbeaks. Birds also collide with lighthouses, radio 

 towers, transmission lines, large plate-glass windows, airport ceilometers, 

 and bridges. 



Little quantitative data on collision fatalities are available for coastal 

 Maine. Kills have been reported for lighthouses and airport ceilometers 

 (Ferren 1959; Fobes 1956; Packard 1958; and Reitz 1954) but mortality at large 

 towers has not been reported in the coastal zone. Plate glass windows on 

 large buildings and houses result in the death of many migrating birds. 



16-30 



