1887.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 633 



OBSERVATIONS ON THE BIRDS OP SOUTHWESTERN TEXAS. 

 By ('IIAI£liB:M \» B « IS 8,11 FFK BKCKITAITI. 



Southwesteru Texas has always been regarded as one of the most 

 prolific fields for zoological research comprised within the limits of the 

 Nearctic region, and, as far as the birds are concerned, it affords some 

 very interesting problems of fauna! distribution. 



It was my fortune to spend the latter half of the month of December, 

 1880, and all of the months of eTanuary, February, and March, 1887, at 

 four ditlereut places in this region collecting and studying the birds 

 found there. The localities were San Antonio and Leon Springs in 

 Bexar County ; Beeville in Bee County, and Corpus Christi in Nueces 

 County, on Corpus Christi Bay, at the mouth of the ]^ueces River. By 

 reference to a map it will be seen that these four points are located ap- 

 I)roximately on a line, trending northwest and southeast, of about 70 

 miles in length. 



At first it was my purpose to record only the results of my own obser- 

 vations, but upon reflection it seemed better to embody the notes of the 

 other observers who had collected in the same localities,*and thus pre- 

 sent a pretty fair picture of the avifauna along what I believe to be an 

 important line of faunal inosculation, if such a term is permissible. 



Mr. iST. C. Brown, in the first of his papers on the Birds of Kendall 

 County, which adjoins Bexar County on the northwest (Bull. N. O. C, 

 1880, p. 33), alludes to this remarkable intermingling of Eastern and 

 Western Province birds, and remarks particularly the intergradation 

 shown in the cases of the Song Sparrow and the Pipilos. This mixing 

 up of geographical races which my material illustrates is by far the most 

 interesting fact in connection with my observations in Texas that has 

 come to my knowledge, although this occurrence of intermediate forms 

 is just what was to have been expected. As examples I may cite the 

 cufies of MGlothrus afer, and M. atcr ohscuriis, Chondcsfes grainmacus, and 

 C. grammacus strigatiis, Poocaies gramineus, and P. gramineus co)iJinis, 

 etc., all of which are more fully explained in another place. 



San Antonio, in Bexar Count}^ G80 feet above the sea-level, where most 

 of n)y observations were made, is a peculiarly favored locality for birds. 

 The San Antonio Eiver, a respectable stream for southwestern Texas, 

 has its source a mile or two above the town in several very large springs 

 which issue from a soft limestone belonging to the Cretaceous series of 

 formations, and which is the surface rock in this region. These springs 

 or fountains unite to form the river, which, after winding through the 

 town in a very tortuous course, is Joined some distance below by the 

 San Pedro, a large creek having a source of supply similar to that of 

 the river. 



