Reproductive allocation within a polygyne, polydomous colony of the ant Myrmica rubra

1. Ant colonies commonly have multiple egg-laying queens (secondary polygyn y). Polygyny is frequently associated with polydomy (single colonies occupy multiple nest sites) and restricted dispersal of females. The production d ynamics and reproductive allocation patterns within a population comprising one polygyne, polydomous colony of the red ant Myrmica rubra were studied. 2. Queen number per nest increased with nest density and the number of adul t workers increased with the number of resident queens and with nest densit y. This suggests that nest site limitation promotes polygyny and that worke rs accumulate in nest units incapable of budding. 3. Nest productivity increased with the number of adult workers and product ion per queen was independent of queen number. Productivity increased with nest density, suggesting local resource enhancement. This shows that produc tivity can be a linear function of queen numbers and that the limiting fact or is not the egg-laying capacity of queens. 4. The total and per capita production of reproductives decreased towards t he periphery of the colony, suggesting that the spatial location of nest un its affects sexual production. Thus nests at the periphery of the colony in vested more heavily in new workers. This is consistent with earlier observa tions in plants and could either represent investment in future budding or increased defence. 5. The colony produced only five new queens and 2071 males, hence the sex r atio was extremely male biased.