136 Charles K. Smith 



The ponds were visited during the day once a week, and on every 

 rainy night beginning with the first rains of late fall (19 December 1979 

 and 1 November 1980). During each visit the ponds were searched for 

 adults and egg masses. Developmental stages of the embryos were used 

 to determine lengths of the breeding, incubation, and hatching periods. 

 Masses in early stages of development (preblastula) were assumed to be 

 recently deposited. In addition, data on the number of eggs per mass, 

 mass size (greatest length and diameter), and mass placement were col- 

 lected from Pond 3 on 23 March 1980 and 8 March 1981 while transects 

 were waded across the pond. 



RESULTS AND DISCUSSION 



A summary of breeding and incubation periods oi Amby stoma jef- 

 fersonianum is given in Table 1 . Substantial differences occurred between 

 years in the initiation and duration of the breeding season. Hatching, 

 however, occurred over a 1 to 2 week period at approximately the same 

 time during both years. 



Since the migration oi Amby stoma to breeding ponds is correlated 

 with precipitation and temperature (Baldauf 1952; Whitford and Vin- 

 egar 1966; Douglass and Monroe 1981), variable weather conditions 



Table 1. Summary of dates and duration of breeding and incubation periods for 

 Ambystoma jeffersonianum in three central Kentucky Ponds. ' 







1980 







1981 





Ponds 



1 

 19 



2 



3 



P 



2 



3 



Initiation of 



3 



22 



21 



21 



21 



breeding period 



Jan. 



Jan. 



Jan. 



Feb. 



Feb. 



Feb. 



Egg deposition 



6 



11 



9 



- 



3 



3 



period (wks) 















Incubation 















period (wks) 



4-10 



4-13 



4-10 



- 



3-6 



3-6 



Hatching 



23 Mar. 



30 Mar. 



30 Mar. 



- 



28 Mar. 



28 Mar. 



period 



5 Apr. 



5 Apr. 



13 Apr. 



- 



5 Apr. 



5 Apr. 



' Dates are approximate 



, based on first observation of the event. Duration of an 



event is based on observations of first and last occurrence. 







2 Drying destroyed all eggs in pond 1 during 1981; 



see text. 







