GROUSE LIBERATIONS 507 



seem not to acquire a strong fear of him, even after some time spent in their native coverts. 

 Breeding birds escaping from the Research Center are occasionally picked up in the yards 

 or gardens of the surrounding farms. One such bird traveled three miles during a period of 

 several weeks, only to be caught quietly feeding in a greenhouse. Another, liberated on the 

 Hyde Park estate of President Franklin D. Roosevelt, was killed in Poughkeepsie six miles 

 away. 



Of the marked birds subsequently contacted from among the 191 hand-raised grouse, not 

 necessary for propagation experiments and therefore available for liberation, about one- 

 quarter never established a fear of man, one-half would flush at distances of from 25 to 50 

 feet when approached and the remainder compared well in wildness to native birds on the 

 liberation area. 



With wild-trapped stock the situation obviously is somewhat different. Unless they are kept 

 for a month or more in constant contact with people, they usually remain wild both in cap- 

 tivity and when released. Only adults are trapped for restocking, for the younger birds from 

 six to ten weeks of age are usually quite difficult to catch. Where the birds are heavily hunted 

 and therefore difficult to approach, as in the Northeast, the Investigation found it practicable 

 to trap birds for banding only on the nest or in the late fall or winter*. For this reason re- 

 stocking with grouse in the younger age classes has seldom been attempted. 



Age 



The tanieness of artificially-raised adults mitigates against their utili/ation for liberation. 

 Young birds, however, are much more adaptable than are the adults. In restocking a covert, 

 the age of the birds liberated often exercises a measurable effect on the results attained. Most 

 game birds raised in captivity seem to adapt themselves best to a new environment at a rela- 

 tively early age. Experience to date indicates tliis may also be true of young grouse. 



There are no published records to indicate that any number of young grouse six to eight 

 weeks of age have ever been released. At the Center, in order to secure the proper records of 

 survival to be utilized as one criterion in the selection of the following years' grouse breeders, 

 all young birds, except escapees, have been carried through to October before those to be 

 liberated were chosen. 



Though few records are available to support the theory, it was observed that those birds 

 accidentally liberated from the rearing pens in August usually went native quickly. Few of 

 these birds were subsequently recaptured. Some were recognized months later by their col- 

 ored leg bands. 



The indications are, then, that the best age at which to liberate captivity-raised grouse, is 

 when they are eight to ten weeks old. Older birds are more likely to seek the habitations of 

 man unless they are liberated at a considerable distance therefrom. 



Physical Conditions 



Another common cause for the failure of liberated birds to survive is poor physical condi- 

 tion at the time of release. In 1931 the Investigation received a shipment of .34 Canadian 

 birds, only 18 of which were in fit shape for liberation. That this situation is not unusual is 

 indicated by many similar reports such as one from Martha's Vineyard where many of the 

 birds received were described as "sick if not dead." Those released were never heard of again. 

 Or. the other hand, two shipments from Nova Scotia arrived in excellent shape. 



* See Appendix, p. 716. 



