Show y Poison Gas for Pests In some sections of of- the country certain species of birds are a pest which annually destroys fruit and grain mounting into tens of thousands thousands thousands thou thou- sands of dollars The United States biological survey and tae me warfare service have joined forces to combat the destructive nuisance if possible Some of th birds travel In great flocks Notable among these are the blackbirds which are said to be re re- for much damage to growing growing growing grow grow- ing crops not at al all compensated for forby forby forby by their work as Insect killers It Its s s impossible to destroy these birds with poisoned bait but as they roost on on the reeds in the marshes it is thought that they can be killed by a agas agas agas gas cloud at night when the wind Is favorable Imperial valley California California Cali Calf fornia has been selected as the place for Cor the first experiments on a large scale The blackbirds are migratory ana return to the same places year after year It Is thought by experts that a abig abig abig big killing in a certain locality might free it of the pest for several years A few other birds in to the tIle black black- infested bird-infested marshes will be killed at the same time but the department department depart depart- ment believes that these local birds will soon reach their normal number number num- num ber ier again Arrangements are also being made by the bureaus mentioned for investigating the possibilities of usIng using using us us- ing poison polson gases on such burrowing rodents as rats prairie dogs ground squirrels and woodchucks Tests on pocket gophers and ground squirrels by these two cooperating branches of the government in California show that chlorine may be used with good results if properly handled The chemical warfare service used phosgene on rats in Porto Rico with good results Some of these war gases will be compared with carbon for the killing of woodchucks and other rodents in their burrows |