NAfTURAL HISTORY OF THE KING RAIL 



31 



1960, 1 estimated a density of one pair per acre in the cutgrass marsh 

 bordering the river. A year later I also heard many King, Virginia, 

 and Sora Kails calling at night in the same marsh. 



Much of the refuge canal system and some of the ponds are choked 

 with alligatorweed, a plant that forms extensive mats upon which 

 rails, gallinules, coots, herons, and several species of ducks do much 

 of their foraging for aquatic insects (fig. 14). Small patches of giant 



Figure 14. — Alligatorweed (Alternanthera philocoeroides) in canal at Savannah 

 National Wildlife Refuge, Jasper County, S.C., April 1960. This plant forms 

 spongy, extensive mats upon which rails, gallinules, coots, herons, and ducks 

 forage for aquatic insects, fish, amphibi>ans, and crustaceans. Such mats have 

 an ohvious value to birds that utilize its growth form to facilitate their quest 

 for food. Note alligator on far side of canal. Alligators feed on many forms 

 of animal life including various water-birds such as rails. 



cutgrass in which Purple Gallinules nest are sparsely distributed 

 along the canals. I located many King Rail pairs with feeding terri- 

 tories along sections of the canals. Some of these territories were not 

 more than 20 feet square, indicating the high food productivity of these 

 aquatic mats. All of the King Rails that I observed feeding in the 

 choked-up canals, however, nested on the other side of the dike in a 

 deep-water impounded marsh containing a mixture of giant cutgrass, 

 sawgrass, cattail, royal fern (Osmunda regalis), buttonbush {Oeph- 

 alanthtcs occidentalis) , and myrtle {Myrica cerifera) . 



I made a roadside count of calling males on April 12, 1960, along 

 a 7-mile route beginning at the north entrance to the refuge on U.S. 



