BUREAU OF BIOLOGICAL SURVEY. 425 



NEW LURE FOR MOUNTAIN LIONS. 



One of the important developments of the year has been the intro- 

 duction of oil of catnip as a lure in trapping and poisoning moun- 

 tain lions and bobcats. Heretofore the taking of mountain lions 

 has been exceedingly arduous work because of the rough and inac- 

 cessible country which they frequent and the fact that it has been 

 necessary chiefly to trail them with dogs and to shoot them when 

 treed or driven into caves. A representative of the Biological 

 Survey had ascertained that mountain lions and bobcats were at- 

 tracted by the odor of catnip. Effort was made to obtain an extract 

 of this plant or a synthetic product which would carry the attractive 

 odor in a form sufficiently permanent for use in field operations. 

 Oil of catnip was not produced on a commercial scale and the 

 Bureau of Chemistry advised that only very minute quantities had 

 ever been extracted in connection with laboratory experiments. 



The securing of a supply of oil of catnip for the desired purpose 

 is a most interesting case of effective cooperation. From the Drug 

 Investigations Division of the Bureau of Plant Industry the Bio- 

 logical Survey in 1920 obtained a very small quantity, sufficient to 

 determine that the oil carried the characteristic odor and that this 

 would persist for several months when exposed in the open air. 

 A small area was planted to catnip by the Bureau of Plant Industry 

 on the Arlington Experimental Farm, from which enough was pro- 

 duced to extract sufficient catnip oil for a thorough test in field 

 operations. It was found that the oil of catnip could be diluted 

 with oil of petrolatum and still retain the characteristic odor. This 

 permitted a more extensive use of the limited supply, and through 

 it several mountain lions and large numbers of bobcats have been 

 lured into traps or to take poisoned baits. The odor of catnip ap- 

 pears to exert an almost unfailing attraction for these animals and 

 other members of the cat family. Discovery of this use of the mate- 

 rial is an important contribution to the methods of taking these 

 destructive animals. 



PREDATORY ANIMALS AND GAME. 



State game departments and sportsmen's associations have coop- 

 erated heartily with the bureau in efforts to destroy predatory ani- 

 mals. Timber wolves, coyotes, wild cats, and foxes all join in game 

 destruction, the kill being heaviest in winter when the snow is deep 

 and especially in early spring after the snow becomes crusted. At 

 this period wolves and coyotes often appear to kill for no apparent 

 reason other than amusement or sheer lust of killing. During the 

 spring and summer the losses of young game animals and the de- 

 struction of ground-nesting birds, their nests, and young is one of 

 the most serious checks on game increase. In many sections of the 

 West, where operations have been in progress for a sufficient length 

 of time for the reduction of predatory animals to become effective, 

 State game departments report a notable increase in quail, grouse, 

 and deer. 



