iS8s.] Bicknell on the Singing of Birds. 2 49 



other hand, from just within the desert — the exact locality where 

 the hybrids were found — might have come from Utah or Arizona 

 so far as comparison shows to the contrary. They are in every 

 respect typical of the species and reveal no tendency to an approach 

 towards californicus as a result of their proximity to the habitat 

 of that bird. The specimens in question can, therefore, be nothing 

 else than pure hybrids. 



To what extent hybridization between the two species occurs 

 at this point is at present not known, but Mr. Herron promises to 

 pay attention to the matter and ascertain, if possible, the relative 

 proportion the hybrids bear to the unmixed birds. It will be 

 found, probably, that the hybrids are comparatively rare, as of a 

 considerable number of Gambel's Quails already shot at the 

 same locality, Mr. Herron recalls nothing peculiar. Probably it 

 will be found that actual mating between the two species does not 

 take place, but that the hybrids are the result of unusual meetings 

 between the opposite sexes of the two species, which are more in 

 the nature of accidents than anything else. 



A STUDY OF THE SINGING OF OUR BIRDS. 



BY EUGENE P. BICKNELL. 



[Concluded from p. 154^ 



Agelseus phceniceus. Red-shouldered Blackbird. 



In mild winters squads of Red-winged Blackbirds sometimes 

 wander northward ahead of time. These find the swamps unpre- 

 pared for them, and keep silence save for the dull chuck which it 

 is customary for Blackbirds to use on all occasions. But song 

 always accompanies the general migratory movement however 

 early it may be entered upon, and I have known their spring con- 

 cert to begin as early as February 22. No matter how backward 

 the season, they will not brook more than a reasonable delay, and 

 after the middle of March will come and settle and start singing 

 even when the swamps are still ice-bound and they themselves 

 are the only sign of spring. 



