1985] 
Pamilo, Crozier, & Fraser — Rhytidoponera 
233 
November, whereas ants from nest 61 had been uniformly hostile to 
such ants in September, is not, however, consistent with the 
hypothesis of a multinest colony. That moving in R. sp. 12 rests on 
the pronota of elite movers is consistent with observations from 
other ants (Moglich 1978; Moglich and Holldobler 1974, 1975), as is 
the observation of reduced ovarian activity in these mover workers 
(Moglich and Holldobler 1975). Carrier ants may not, of course, be 
acting in the “interests” of those carried: carrying in Formica aqui- 
lonia (Rosengren and Pamilo 1983) can represent the robbing of 
workers by one nest of another (closer to true slavery than is 
dulosis). 
If carrying is an “amicable” activity, then it might be expected to 
occur between nests more closely related than the average. The 
analyses so far available (Crozier et al 1984) cannot yield that 
information, because the relatedness estimates are regression coef- 
ficients pertaining to the population as a whole. But the determina- 
tion of genetic distances between colonies, based on further data, 
may overcome this lack. 
Acknowledgements 
This work was supported by a grant from the Australian 
Research Grants Scheme to RHC. We also thank the US National 
Science Foundation for a travel grant making JF’s participation 
possible, and Dr. C. Carter, Officer in Charge of Fowler’s Gap 
Research Station, for providing general aid and assistance, and for 
identifying a plant species. 
Summary 
We report studies on the reproductive and foraging biology of 
Rhytidoponera sp. 12, a large ponerine ant which lacks a 
morphologically-differentiated queen caste. 
Based on dissections of 437 ants from an established colony, 
about 7.5% of the mature workers are mated egglayers (equivalent 
to the gamergates of Peeters and Crewe, 1984). These mated 
workers are concentrated in the lower regions of the nest, or move 
preferentially to them during disturbance. Workers taken from the 
upper regions of the nest had low levels of ovarian activity whereas 
unmated workers from the lower regions had high such levels; 
