134 THE RIDDLE OF MIGRATION 



and return them to the University for examination. 

 Every bird was banded. Since Sunday shooting is 

 prohibited in Alberta, the crows had nearly 48 hours 

 in Avhich to get accustomed to their regained free- 

 dom and to choose their roads before being hunted. 

 The controls were turned out together with the 

 experimentals. The following Monday being 

 Thanksgiving Day it was hoped that crow shooting 

 would be widely indulged in and our returns duly 

 benefited. The birds remained wild and wary, 

 however, and although hundreds of gunners turned 

 out, only a small percentage of birds was retaken. 

 This was disappointing for had it not been for the 

 incidence of this national holiday on the 11th, the 

 birds would have been liberated two weeks later. 

 Interstitial tissue was just appearing in the testes of 

 the experimental samples but two more weeks of 

 lighting would probably have produced greater uni- 

 formity. As far as the controls were concerned we 

 felt that we were perhaps liberating them pre- 

 maturely and that some of them might still proceed 

 south, but the advantages of a large turn-out on 

 Thanksgiving Day promised to outweigh the dis- 

 advantages of a somewhat early liberation. 



Of the 69 experimentals, all but 28 left for good. 

 These were retaken within three days, given two 

 additional weeks of lighting and then again turned 



