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[Vol. 91 
again. The copulating male stayed in the male-above position, and 
copulation was not prolonged. After copulation, the male dis- 
mounted and flew away, leaving the female outside her burrow. The 
rival male then located the female and mated with her. 
Discussion 
Females are difficult for males to locate (Lloyd 1979). With a 
period of only about 18 min nightly to operate in, the usual male 
strategy after finding a female is to mate and, within a minute or so, 
return to the air searching for another female. 
Females pause after mating, but do not answer the flashes of 
passing males. They then enter the burrow. Less than 3% of the 
females that mated ever made themselves available to males again 
(also see Wiklund 1982), and those that did may have had some 
fault in the mechanism that indicates whether sufficient sperm was 
acquired (also see W. Walker 1980). 
During the pause before re-entering the burrow females are 
susceptible to another mating if found. Even after re-entering the 
burrow a female may be dug up and remated. Generally, then, if a 
male can gain physical access to a female, he can mate with her. The 
fact that an accessible female could be mated if found has led to 
prolonged copulation when a rival male is present (Parker 1970). 
Copulating males make the female physically unavailable by 
occupying her until she has returned to her burrow (see Sivinski 
1983). Rival males try to break the coupled pair apart and attempt 
to gain access to the female by digging her from the burrow. The 
“sneaky” rival avoids triggering mate-guarding by the coupled male, 
and thereby gains access to the female after her first mate leaves. 
The frequency of male encounters with rivals might vary with 
male density, but the overall proportion of females that mate 
repeatedly is probably rarely if ever much greater than the four per 
hundred found in this study. 2 The complex of male strategies and 
counter-strategies shown here reflects how important the potential 
for female multiple mating can be, even when only a small 
proportion of females actually mate more than once. 
2 Based on 71 matings observed when male density was at a 3-year peak (Wing 
unpublished data). It should also be noted that mated females are sometimes flooded 
from their burrows, and may remate under these circumstances (Wing 1982 and 
unpublished). 
