100 
Raymond D. Semlitsch and Michael A. McMillan 
RESULTS AND DISCUSSION 
Breeding migrations. —The peak terrestrial activity period for adult 
E. quadridigitata appears to be late July through October (Fig. 1). During 
the 1978 season, animals caught between 21 September and 14 October at 
Rainbow Bay (N = 122), and on the night of 30 September, at Ellenton 
Bay (N = 40), represented mature adults entering the bays. Likewise, the 
majority of E. quadridigitata caught from 14 July through 30 October 
1979 (N = 164) were adults entering Rainbow Bay in breeding condition 
(males with enlarged cirri; gravid females). Since these incoming 
salamanders were mature and in breeding condition we assume they were 
entering the bays to breed. Breeding migrations during 1979 appeared to 
be more diffuse than during 1978. This could be due to rainfall pattern, 
since the autumn of 1978 was very dry, whereas rainfall occurred fre- 
quently during the autumn of 1979 (Fig. 1). The amount and timing of 
rainfall has been shown to be an important proximate factor that may 
determine the onset and duration of these breeding migrations of other 
salamanders (Baldauf 1952; Shoop 1960, 1965; Gill 1978). There was no 
correlation between total number of captures per week and cumulative 
rainfall for the week or mean minimum and maximum air temperatures 
(r = 0.16, p > 0.10; r = 0.09, p > 0.20; r = 0.14, p > 0.20; respectively). 
Fig. 2. Size-frequency distributions of breeding Eurycea quadridigitata entering 
Rainbow Bay and Ellenton Bay from 21 September through 30 November 1978. 
