ORTMANN : THE CRAWFISHES OF THE STATE OF PENNSYLVANIA 495 



dentally, but must have been brought in by the crawfish. In one case (October 9, 

 1905, Nine-Mile Run), I found in a side-pocket of a hole of a female C. monoiigalen- 

 sis a number of ripe fruits of GraUpgux, about a handful, which under no circum- 

 stances could have fallen into the position where they were found. The hole was 

 under a large Crataegus bush. 



Thus it seems that any vegetable or animal matter, either fresh, or decaying, 

 serves as food for crawfishes, and although some species may prefer certain classes of 

 food on account of taste or necessity, they all take readily to any kind, as is seen by 

 the fact that in captivity they eat everything that is offered to them without dis- 

 crimination. If nothing is given, the}' eat one another. 



Crawfishes in turn serve as food for many animals, chiefly those which are 

 aquatic. Among mammals we know that raccoons hunt for them. As has been 

 mentioned above, birds eat them, and the kingfisher and other equatic birds do so 

 quite regularly. The report of Audubon, (see Ortman, 1900, p. 1250), that the White 

 Ibis captures the cliiinne3'-builders by throwing fragments of the chimney into the 

 hole, and watching for the crawfish to come up, does not seem strange to me. At 

 Ohiopyle I was told that a domesticated turkey kept upon the grounds of tlie hotel 

 had the habit of watching the holes of C. carolimis, and that frequently he captured 

 this species. I have myself seen this turkey standing motionless before a hole, but 

 I (lid not observe the actual capture. I do not entertain the slightest doubt that 

 this and other birds are able to catch crawfishes in this way, and do not think that 

 it is necessary to drop dirt into the hole, since the crawfish conies up frequently on 

 its own account, when it may be seized. 



Crawfishes constitute an important part of the diet of certain snakes, more par- 

 ticularly of the water-snakes, Nairix sipedon and leheris. 1 have seen the latter dis- 

 gorge C. obscurus when captured. (See also Atkinson, Ann. Carn. Mus., I. 1901, p. 

 149, 150.) On two occasions I have found garter snakes, EuUenia sirlalh, in holes of 

 G. monongahnsis ; two specimens of this snake in one hole on Octol)er IH, 1904, 

 (Fern Hollow), and one snake in a hole on October 28, 1905, (Edgewood I'arkK 

 However, whether the snakes were after the crawfishes, or whether they simply were 

 using the holes for winter quarters, remains doubtful. 



Professor H. A. Surface writes to me tiiat Criiiiloln-nnclin.'^ tillcglicitini.s-!.'< and Xcc- 

 turus maculosus are among the chief enemies of the crawfishes, and, indeed, these 

 two salamanders are generally found at places where crawfishes abound. (Comjiare 

 Eydeshymer, American Naturalist, XL. \'.H)C>. j). 128.) 



They are, however, most valuable a.s food for the tish-fauna of our watei-s. As 

 has been mentioned above, crawfishes are good bait for certain fishe.-;, and it is very 



