100 SEVENTH REPORT. 



VARIATION IN THE BLUE RACER. 



C. C. WHITTAKER. 



In the Amer. Nat., Vol. 73, Jan., 1903, Dr. Clark summarized his 

 work on our common water snakes Natrix leberis/N. fasciata sipedon, 

 and 'Natrix erythrogaster, and in the Pro. Mich. Acad, Sci., 1903, Mr. 

 Sperry summed up the results of his investigation of variation in our 

 common garter snake ThamnopMs sirtalis comparing its variation with 

 that of Erythrogaster and Hipedon. The present paper will follow the 

 same general outline and aims to sum up the variation observed in the 

 blue racer, (Bascanion constrictor) and compare the variation of that 

 snake with that of Natrix and Enta&nia. The deductions with regard 

 to the blue racer are based upon .58 specimens taken in the springs of 

 1903 and 1904 in Olivet and vicinitv.* 



NATURAL HISTORY. 



The habits of Bascanion have been so fully given by Cope (Rep. Nat. 

 Museum, 189S, ]>p. 783-795) as to need no general discussion here. The 

 color of the Michigan blue racer when adult is very constantly a dull 

 brownish blue color, and more or less clear light blue below. These 

 snakes are exceeding active and can travel as fast as the average man 

 can run. They are good climbers and will sometimes take to trees to 

 avoid capture. Their pugnacity is very marked and they will strike 

 viciously when attacked, some individuals will even assume the offen- 

 sive and move to the attack with the head raised a foot or two from 

 the ground, especially when cornered, and if a person is timid and 

 shows a disposition to retreat, they may even pursue. 



The fear so commonly aroused by these snakes is however entirely 

 groundless. The wound made by a blue racer bite is very slight and 

 almost painless. If one could overcome the instinctive retraction when 

 the snake strikes it may even be doulited if their tiny teeth would draw 

 blood. Of course, retraction causes them to scratch and sometimes the 

 wound will then bleed freely. Their constricting power even if used 

 certainly is not dangerous to any except very small children. Cope's 

 statement that they are easily tamed is open to question. Specimens 

 kept in confinement for over a year were as pugnacious at the end as at 

 the beginning of confinement. It seems, however, to be largely a matter 

 of individual temperament, as one young male was very gentle when 

 taken and remained so in captivity. Older specimens, especially of the 

 males are very savage. The chief food of the blue racer consists of 

 moles, mice, young birds, and birds eggs. They do not, as many suppose, 

 eat frogs, at least none of the Olivet specimens, even when hungry, 

 could be induced to do so. 



* The term variation has been objected to in this connection but since it was used in similar 

 papers by Messrs. Clark and Sperry it is thought best to retain it here even though some other term, 

 such as diversity, might be preferable. 



