THE REPTILES OF OHIO 237 



Natrix sipedon msularutn Conant and Clay 

 Lake Erie Water Snake 



(Page 86; maps 19 and 56; plate II, fig. 2) 



Among the new Ohio records for imulariim are the following: 



Ottawa County: Fisher's Pond. Middle Bass Island (ROMZ 5732); Gibraltar 

 Island, Put-in-Bay (CM 19038; ROMZ 5730); Green Island (OSM 850.1-32); 

 North Bass Island (CA 6020); South Bass Island (CA 5248; OSM 612-3, 834.1-4, 



851.1-24, 852.1-23, 853.1-20, 854.1-16, 855.1-17, 856.1-11, 857.1-30, 858.1-7, 859.1- 

 16; ROMZ 5549). 



The extraordinary abundance of this snake on many of the islands in Lake 

 Erie has been repeatedly demonstrated. A large catch, made on South Bass 

 Island on June 1, 1935, has already been described (page 87), and several 

 other collectors have obtained specimens in numbers on the same r.nd on other 

 islands. Trautman, who has been resident in the archipelago for ten years, 

 advises me. however, that insularum is now far less comm.on on the inhabited 

 islands than formerly. On small, outlying islands, where it is more or less 

 free from human predation, this subspecies appears to be holding its own. 



Thomas (1949) reported on a large population that he encountered on 

 Middle Island, Ontario, which lies just north of the Ohio boundary and which 

 has had no human residents since about 1933. His visit was made on August 

 30, 1945, and a great number of large water snakes were seen sunning or lying 

 in the shade of shrubbery on limestone ledges running along the north shore 

 of the island. Juveniles were conspicuous by their absence. A party of seven 

 persons visited the same island on April 30, 1949. and they succeeded in cap- 

 turing 600 snakes during the course of the day. Of these, about 200 were 

 Thamnophis s. sirtalis (including two melanistic individuals), live were 

 S tor end dekayi, and the remainder were insularum. Triplehom, who was a 

 member of the party, states, "During the morning few specimens were seen 

 ranging or sunning, and, although we collected between 200 and 300 snakes 

 before noon, we got fewer than two dozen juveniles. In the afternoon we 

 began to see the water snakes sunning themselves, but not along the water as 

 we had expected. They were all about fifteen to twenty yards from the water's 

 edge, and many were far inland. Early in the afternoon we came across an 

 old well which was banked rather deeply with limestone. From this small 

 area (about 5 feet square) we pulled 90 snakes, all but about two dozen of 

 which were juvenile insularum, probably of last year's litters." 



Only two specimens were collected during Thomas' visit to Middle Island, 

 but both were exceptionally large; one measured 49 inches in length and the 

 other was 504^4 inches. Not only is the latter snake the largest ins:t!arvm on 

 record, but it also contained the amazingly high number of 57 embryos. The 

 other snake had 25 embryos. The Ohio Snake Museum collection has recent- 

 ly been augmented by skins, embryos, etc. representing ten litters of insularum 

 from South Bass Island; the young in these number 6. 10, 15, 15, 16, 19, 22, 

 23, 29, and 31, respectively. 



The extraordinary amount of variation that occurs in the dorsal and ventral 



