36 Mark S. Davis and George W. Folkerts 



from mid- January to late February. Calling began on 21 February dur- 

 ing the 1979 breeding season (air and water temperatures 11 °C). 

 Although egg deposition was completed in all pounds by 1 March, 

 males continued to call intermittently until 5 March. Similar postbreed- 

 ing calling was noted by Waldman (1982). Breeding occurred sporadi- 

 cally between 21 February and 1 March whenever air temperatures were 

 above 5 °C. Vigorous calling occurred on 22 February (air 16 °C, water 

 14 °C) and 24 February (air 16 °C, water 12 °C). No calls were heard 

 after 5 March even though air and water temperatures were above 10 

 °C. In 1980, males began calling on 17 January after unseasonably 

 warm weather (air 15.5 °C, water 9 °C, at 2130 CST), but calling ceased 

 early the next morning when the temperature dropped considerably (air 

 4 °C, water 9 °C, at 0200). Males were in full chorus in all ponds visited 

 on 22 January (air 9 °C, water 12 °C, at 1915). Egg deposition was 

 completed in all ponds by 22 January. 



Development of Ovarian Eggs 



Females collected throughout the year yielded information on egg 

 development. Body weights of preserved specimens before ovary re- 

 moval, ovary weights from each specimen, and ovary weights as a per- 

 centage of body weights are given in Table 1. Eggs were stored in 

 ovisacs in one female that had completed ovulation. For this specimen, ovisacs 

 (instead of ovaries) with ripe oocytes are expressed as a percentage of 

 total body weight, as indicated. 



Examination of females indicated that ovarian weight (expressed as 

 a percentage of body weight) remains fairly constant from early Sep- 

 tember to late November. No preovulating females were collected 

 immediately prior to the breeding season, but we assume that the great- 

 est increase in size of oocytes occurs during this time (later stages of 

 vitellogenesis). All gravid females collected in the breeding ponds had 

 completed ovulation and mature ova were present in the ovisacs. Ovi- 

 sacs in a gravid female collected in the breeding pond on 18 January 

 composed 41.7% of the total body weight. Ovarian weight in spent 

 females drops to 3.9 to 5.0% of total weight. The ovaries of a female 

 collected on 14 May were macroscopically similar in appearance to 

 those of spent females. In this female, ovaries equaled 5.3% of total 

 body weight. 



Because no females were collected between May and September, we 

 could not determine when oocyte enlargement begins; however, based 

 on the size and appearance of oocytes in females collected during Sep- 

 tember, we estimate that enlargement begins in July or August. Because 

 ripe oocytes in gravid females compose such a large percentage of total 



