16 2 HE A UD UB O Ne BUT eee 
contained four dead nestling robins, surrounded by dead carrion beetles 
which had in turn been poisoned. 
Adult birds may fly many miles from a sprayed area before they are 
seized by the convulsions which precede death from DDT. It should also 
be borne in mind that insectivorous birds avoid or abandon any territory 
in which insect life has been practically exterminated. This explains the 
disappearance of birds from many areas subjected to repeated heavy spray- 
ing. Practically all our land birds are insectivorous in the nesting season. 
The opinions of many qualified officials who have generously cooperated 
in our survey emphasize that rigorous measures should be taken by 
farmers, municipal authorities, golf course officials and other private 
property owners to avoid damage from using excessive amounts of these 
poisons. The experience of the fish and wildlife service in treating many 
types of land should serve as a dependable guide to safe, effective con- 
centrations for various purposes. 
With regard to DDT, the fish and wildlife service recommends the use 
of less than one-fifth pound per acre over water or marsh — in oil solution, 
not in dust — to avoid kills of fish, crabs and crayfish. Less than two 
pounds of DDT per acre should be used even in forest areas, to prevent 
death or injury to birds, frogs and mammals. On turf and lawns heavily 
infested by Japanese beetles, effective larva control can only be carried out 
by concentrations as high as 20 or 25 pounds of actual DDT per acre. 
DDT should be applied in early spring for early insects and not again 
until late July or August, after the bird nesting period, to control late 
appearing insects. The extreme sensitivity of fish and crabs to this poison 
makes its direct application inadvisable on streams, lakes and coastal bays 
where injury would be inflicted on commercial or sport fishing, and on 
ducks, shorebirds and other species which feed on aquatic animals. 
The National Audubon Society would welcome specific reports of insecti- 
cide experience from entomologists and other qualified individuals or organ- 
izations. Such observers should carefully determine the concentrations and 
amounts employed, as well as the specific mortality or reduction in bird or 
other animal population that may result in a given area. 
ff fi fH 
Peterson Makes It Easy 
“How To Know the Birds” is Roger Tory Peterson’s latest addition to the 
fund of information he ‘has made available to bird students. It is designed 
primarily for the beginner, but experienced field students will find that it 
puts into a few sentences and in proper order for quick identification the 
characteristics which will help the observer classify ‘a bird in its family 
group and narrow the possibilities as to species. Containing 400 line 
drawings and much detailed information, it comes in two editions priced 
at $2 for the bound volume and only 35 cents for a water-proof paper cover 
edition. If it is not available at your retail book shop, either edition may 
be purchased through the Service Department, National Audubon Society, 
1000 Fifth avenue, New York 28, 'N. Y. 
