^°'l (^^^1 Mearss, Bescrif^iOH of a Hybrid Swallozv. 73 



DESCRIPTION OF A HYBRID BETWEEN THE BARN 

 AND CLIFF SWALLOWS. 



BY EDGAR A. MEARNS. 



In the 'Bulletin of the Nuttall Ornithological Club,' Vol. Ill, 

 No. 3, July, 1878, page 135, Doctor Spencer Trotter described a 

 hybrid between Hirundo eryt/irogaster Boddaert and Fetrochelidon 

 lufiif/vns (Say). The specimen was taken at Lin wood, Delaware 

 County, Pennsylvania, May 22, 1878, by C. D. Wood. "Unfortu- 

 nately he [Wood] did not carefully determine its sex by dissection, 

 though he believed it to have been a male." 



On June 14, 1893, at Fort Hancock, El Paso County, Texas, 

 I found a pair of swallows which were mated, and had almost com- 

 pleted a nest attached to a rafter of an old building, in a situation 

 too difficult for jne to reach. As I recall it, the nest was similar 

 to that of the Barn Swallow, having the entrance at the top. Both 

 birds were shot. The male (No. 134,420, U. S. National Museum) 

 Avas a typical Barn Swallow; but the female (No. 134,421, U. S. 

 National Museum), which was about to lay eggs, was a hybrid 

 between Hirundo erythrogaster and Fetrochelidon iiinifrons} It 

 may be described as follows: Length, 149 mm.; alar expanse, 

 296; wing, 107; tail, 59; culmen (chord), 8; tarsus, 12; middle 

 toe with claw^ i5-8.'^ The characters are, in general, intermediate 

 between those of the two genera — Hirundo and Fetrochelidon — 

 and species. As regards the form of the bill and the form and 



1 The resident Cliff Swallow of the Rio Grande Valley is Petj-ochelidon 

 l7inifro7ts, not P. melanogaster, which latter occurs on the Mexican boundary 

 line to the westward, from the San Luis Mountains to Nogales (monuments 65 

 to 122 of the latest survey). See Proc. Biol. Soc. Washington, Vol. XIV, 

 September 25, 1901, p. 177. 



^ Its mate, a typical male of Hirundo erythrogaster, measures: Length, 169; 

 alar expanse, 308 ; wing, 114; tail, 82; culmen, 6.9; tarsus, 11; middle toe 

 with claw, 16.2. 



An adult female of Petrochelidoti Intiifrons (No. 163,687, U. S. National 

 Museum), taken at Fort Clark, Kinney County, Texas, April 28, 1898, measures : 

 Length, 145; alar expanse, 300; wing, 106; tail, 53; culmen, 7.7; tarsus, 

 14.5; middle toe with claw, 16. 



