720 U.S. NATIONAL MUSEUM BULLETEST 237 part 2 



Distribution 



Bange. — The San Benito Savannah sparrow is rasident on the 

 San Benito Islands off central western Baja California. 

 Egg date. — San Benito Islands : 1 record, April 1 . 



PASSERGULUS SANDWICHENSIS GUTTATUS Lawrence 



Abreojos Savannah Sparrow 

 Contributed by Wendell Taber 



Habits 



The "guttatus" group occurs in the southern part of the western 

 Baja California peninsula from Pond and San Ignacio Lagoons south 

 to Magdalena Bay. It is distinct from beldingi and anulus in the 

 notably diffused and blended character of the dorsal plumage with 

 much less contrast between feather centers and edgings, even in fresh 

 fall plumage. The color tone dorsally is olive and the superciliary 

 streak is normally yellow at all seasons. When compared with anulus 

 to the north, the biU of guttatus averages decidedly larger, the tail 

 longer, and the dorsal coloration distinctly dull, olivaceous gray with 

 the pattern relatively inconspicuous and diffused instead of con- 

 trasted. When compared with the other member of the "guttatus" 

 group, magdalenae, the size averages smaller in aU dimensions except 

 for the slightly longer biU. Also, the coloration is darker and the 

 dorsal pattern is less conspicuously contrasted. 



McGregor (1898) described, at Abreojos Point, what he thought 

 at the time was the habitat, nest, and eggs of a new species, Ammo- 

 dramus halophilus, which has since been reduced to the synonomy of 

 P. s. guttatus. He states the birds were "found in a salt marsh about 

 five miles long by half a mile wide. The common amphibious plant 

 known as glasswort (Salicornia ambigua) covers the moist ground. 

 The entire marsh is cut by tide creeks, which empty into a salt lake 

 or pond lagoon. As the marsh is surrounded by ocean on one side 

 and hot desert on the others, it is probable that A. halophilus [P.s. 

 guttatus] is confined to that region." 



The single nest McGregor found was 16 inches from the ground 

 in a tall bunch of glasswort, the top of which was bent over and in 

 to form a covering. The nest was made of salt grass and fined with 

 fine shreds of grass and a few gull feathers. The three bluish-white 

 eggs were heavily marked all over with large blotches of raw umber 

 and smaller spots of lilac. As he found a nest and eggs in mid-April 

 and collected females ready to lay in mid-June, McGregor (1898) felt 

 that two broods were probably raised in a year. 



