20 Grinnell, Large-billed Sparrow. ffa'n 



Santa Barbara " [!]. Also : "Its breeding habits are so similar to 

 those of the Belding Marsh Sparrow that no separate description 

 is necessary." What positive assurance ! Such things would be 

 only amusing if they were not a menace to the reputation of orni- 

 thology as a serious science. 



In recounting the foregoing evidence I have not been endeav- 

 oring to prove that the Large-billed Sparrow does not breed at 

 all ! But simply that its whereabouts during the nesting season 

 are not so far definitely known. This is for us to yet find out. 

 To sum up, Passerculus rostratus is a migrant, occurring in winter 

 on suitable seashores from Cape St. Lucas and Guaymas, Mexico, 

 north as far as Santa Cruz, California. Its numbers are large 

 enough so that its time of arrival and departure are easy to 

 determine. But the interval between its departure in the spring 

 and arrival in the autumn amounts to a period of four months, 

 during which we know nothing of its whereabouts. It might not 

 be a sin to speculate somewhat in this regard. 



On the Atlantic coast a similar problem puzzled ornithologists 

 for many years. The Ipswich Sparrow occurred on the coast of 

 New England in winter, but totally disappeared in summer, no 

 one knew where. The breeding grounds were finally discovered 

 to be on Sable Island near Nova Scotia, to which it is now known 

 to be exclusively confined during the nesting season. I once 

 thought that Passerculus rostratus might have a similarly restricted 

 habitat to the northward or westward somewhere. But all of the 

 Santa Barbara' group of islands have been explored in summer, 

 and so has every other likely locality on the coast and islands 

 of British Columbia and Alaska. That the Large-billed Sparrow 

 has a northern insular breeding area, paralleling the case of the 

 Ipswich Sparrow, seems to me therefore extremely doubtful. 



The alternative theory is that the Large-billed Sparrow breeds 

 somewhere to the south of its winter home, and migrates north in 

 the fall, returning southwards each spring! Such a suggestion 

 may seem absurd, but nevertheless fits best the limited amount of 

 data so far in our possession. This possible southern summer 

 home may exist on either coast of Lower California, or on the 

 coast of Mexico, great stretches of which remain unexplored. 

 The possibility that the closely related forms sanctorum and gutta- 



