860 U.S. NATIONAL MUSEUM BULLETIN 237 part 2 



as in its technical binomial. Many systematists consider it only a 

 well-marked subspecies of A. maritima; among those who have written 

 me to that effect are O. L. Austin, Jr., R. A. Paynter, Jr., and C. G. 

 Sibley. Beecher (1955) lists it subspecifically as A. maritima mirabilis. 

 Griscom (1944) writes: 'A. mirabilis (Howell) * * * has no real 

 claim to specific distinction, certainly none of equal weight with those 

 of nigrescens." After discussing the various differences he adds: 

 "These are all differences of degree, none are absolute. Indeed it 

 could be argued that the whiter underparts of mirabilis deprive 

 nigrescens of one of the latter's absolute characters." 



Although I am not a systematist, it seems to me that the differences 

 in color between mirabilis and the races of maritima, or even between 

 mirabilis and nigrescens, are no greater than, for instance, those be- 

 tween certain races of the song sparrow or of the rufous-sided towhee. 

 The similarities between mirabilis, nigrescens, and the maritima 

 subspecies in song, nesting habits, and other behavior are striking, 

 and the differences very slight. The present complete isolation of the 

 mirabilis population from all other seaside sparrows in Florida can be 

 explained by recent geological events (Stimson, 1956). However, 

 the A.O.U. Check-List stiU considers it a full species, and until the 

 Check-List Committee rules otherwise, we will have to abide by that 

 decision. 



The Cape Sable sparrow's only known remaining habitat today is 

 the marshes lying a few miles inland behind the southwest coast of 

 Florida northwest of Cape Sable. Along this coast inland from the 

 Gulf of Mexico first lies a belt of mangroves, commonly called the 

 mangrove fringe, from 2 to 17 miles wide and cut by streams, inland 

 bays, and a few salt marshes. Some of these marshes look from the 

 air as though they might be suitable seaside sparrow habitat, but few 

 have been investigated on the gound. Over the centuries this fringe 

 has acted as a buffer, protecting the adjoining marshes farther inland 

 from the destructive fury of the hmTicanes that periodically sweep 

 the coast. The marshes at Cape Sable lack such protection. 



Inland from the mangrove fringe is a belt of marshes from 3^ to 3 

 miles or so in width. These marshes vary from salt through brackish 

 to fresh, and contain extensive stretches of cord grass (Spartina sp.), 

 which seems to be one of the Cape Sable sparrow's preferred habitats. 

 Bordering the marshes landward are cypress swamps, or strands, and 

 some pine woods interspersed with wet prairie, usually fresh and dry 

 during droughts. From the Lostmans Pine Islands area southeast- 

 ward to Broad River and the Shark River Valley, the forest border is 

 absent and the marshes merge directly into the marsh prairie of the 

 southern Everglades. It was here that the surprising discovery was 



