76 



NORTH AMERICAN FAUNA 67 



From 1959 to 1961, several hundred observations were made during 

 the nesting season of King Rails feeding in brackish marshes along 

 the Delaware Bay between Fleming's Landing and Woodland Beach, 

 Del., where the red- jointed fiddler crab occurs in great abundance. 

 This little crab formed the main diet of the rail ; the only other item 

 of any importance was a clam {Macoma halthica) (fig. 31). Stomach 

 examinations confirmed field observations. 



Table 12, — Principal foods of 118 King Rails from Arkansas ricefields 



[Volume = percent of total volume of stomach contents. Occurrence= percent of stomachs in 



which found] 



Collected in- 

 Winter Spring Summer Fall Annual 

 Food item (Dec.-Feb.) (Mar.-May) (June-Aug.) (Sept.-Nov.) volume, 

 33 stomachs 48 stomachs 16 stomachs 21 stomachs 118 



stomachs 



Vol- Occur- Vol- Occur- Vol- Occur- Vol. Occur- 



ume rence ume rence ume rence ume rence 



Animal: 



Invertebrate: 



Crayfish 



Aquatic beetles. 



Land beetles 



Grasshoppers- 

 Aquatic bugs... 

 Other insects. 



Spiders 



Snails 



Vertebrate: 



Fish 



Frogs 



Miscellaneous.-. 



Total 



Plant: 



Rice 



Ricefield weed seeds. 

 Woody plant seeds-.. 

 Tubers 



Total. 



7 



18 



61 



81 



22 



25 



3 



5 



23 



20 



76 



7 



21 



19 



31 



10 



48 



14 



1 



13 



8 



56 



11 



87 



4 



38 



6 



5 



24 



3 



8 



6 



63 



14 



57 



7 



5 



24 



-1 



15 



10 



44 



6 



29 



6 



- (0 



21 



2 



17 



8 



75 



5 



38 



4 



- (1) 



3 



0) 



2 



(1) 



13 



1 



10 



(1) 



3 



12 



2 



8 



(1) 



6 



(1) 



10 



1 





30 



1 



21 



8 



19 



26 



43 



11 



5 



21 



4 



15 



5 



50 



4 



24 



5 



5 



7 



6 



8 - 











3 





















58 -- 





95 





90 





74 





79 



30 



52 



4 



19 



10 



31 



21 



29 



16 



- (1) 



36 



(1) 



4 



(0 



56 



2 



38 



1 







1 



2 







3 



10 





12 



21 













3 



















42 -- 





5 





10 





26 





21 



1 Trace. 



There is considerable variation in food items taken by different 

 individuals in the same habitat and at the same time. Two birds col- 

 lected from a tidal marsh on the Choptank Eiver in Maryland in 

 February 1961 present an interesting contrast. Bird A fed entirely 

 on fish, while bird B ate a wide and rather unusual assortment of 

 foods including the seeds of arrow-arum, hackberry {Oeltis occiden- 

 talis), halberd-leaved tearthumb (Polygonum' arifoUmrh) ^ dogwood 

 {Comus -fiorida)^ and grape {Yitis sp.). Bird B had also eaten cray- 

 fish and a snail (Gastropoda). The seeds of arrow-arum contain 

 calcium oxalate crystals and apparently are rejected by virtually all 

 water birds except the Wood Duck {Aix sjxonsa) . This was the only 

 time I encountered them during my studies of rail foods. 



Only in the Arkansas ricefields has a fairly complete seasonal 

 survey of King Kail foods been made (Meanley, 1956, p. 252-258). 



