162 A NATURALIST ON DESERT ISLANDS. 



on our previous visit, we only saw a single specimen (a 

 male in full plumage) ; and in January of the year follow- 

 ing that, not a single specimen was seen. The only ex- 

 planation that we can advance, is that possibly this 

 diminutive little bird is in the habit of migrating annually 

 during the winter months to the mainland, flying back- 

 wards and forwards over ninety-five miles of open sea ; 

 or else that it only occurs in casual influxes. In any 

 case, Blanquilla would seem to be the most northerly 

 limit of its distribution. 



A still stranger fact, is that this humming-bird is not 

 found on Margarita Island, which is very much nearer the 

 mainland, where it is common. It can hardly be that 

 the conditions found in Margarita are not suitable, for 

 three other humming-birds are found there. Yet the fact 

 remains, that neither Mr. Wirt Robinson nor Mr. Clarke 

 found it on Margarita during the summer, and I myself 

 only came across one solitary specimen, which was an 

 obvious straggler, during two winter visits,* in which we 

 covered a great extent and variety of ground. Such is 

 another instance of the strange anomalies of distribution 

 so often seen in visiting any outlying islands, all the more 

 strange too, in this case, since the vegetation frequented 

 by this bird on Blanquilla is found in abundance on 

 Margarita. 



But veiy often an island may be almost as interesting 

 for what is does not contain, as for what it does ; and in 

 this connection, we were surprised to find on Blanquilla 

 no examples of the following genera, all of which are quite 

 common along the coast of the mainland, and some of 

 which are also found in the islands of Margarita, Ouragao, 

 Bonaire and Amba. These genera were Cardinalis (cardinal 

 finch), Conurus (parakeet), Quiscalus (grackle). Icterus 

 (yellow oriole), Dendraplex (woodheweT),Melanerpes (wood- 

 pecker), Coereba (honey-creeper), and Polioptila (gnat- 

 catcher). It was all the more surprising, as there 



*Lowe, on the Birds of Margarita Islands, Venezuela. Ibis, 1907, 

 pp. 647-570. 



