Proximate determinants of reproductive skew in ant populations
Final Report Abstract
How reproductive rights are shared among group members and what determines reproductive skew are central questions in behavioral ecology and evolutionary biology. Numerous models explain the magnitude of "reproductive skew", but all assume that Individuals are capable of adaptively adjusting their behavior to the present environmental and social condifions. We therefore investigated whether the reproductive behavior of queens of the ant Leptothorax acervorum from populations with different reproductive skew is flexible or genefically determined. While all populations south of the Pyrenees are characterized by queen-queen aggression and high reproductive skew, queens from central and northern Europe are mutually tolerant, and reproduction is more or less equally partitioned among nestmate queens (low skew). Experimental manipulation of worker numbers and food availability elicited queen fighting In colonies from a low skew population. Furthenmore, exchanging queens between colonies showed that both the origin of workers and queens is responsible for determining the occurrence and frequency of queen antagonism, again suggesting that queen behavior is plastic as suggested by skew models. A phylogeographic analysis of several populations of L acervorum did not suggest a clear separation of high skew and low skew populations. Instead, the haplotype network suggests a central position of the Spanish high skew populations. Microsatellite data suggest that these isolated and decreasing populations are currently still large enough to counterbalance the effects of genetic drift.
Publications
- (2009) Formation of reproductive hierarchies in functionally monogynous colonies of Leptothorax acervorum. 102nd annual meeting of German Zoological Society, Regensburg
Leopold S, Trettin J, Heinze J
- (2010) Occurrence and establishment of reproductive dominance hierarchies in the ant Leptothorax acervorum. 103rd annual meeting of German Zoological Society, Hamburg
Trettin J, Haubner M, Heinze J
- (2010) Queens or workers - who decides about reproductive dominance in the ant Leptothorax acervorum? XVI Congress of International Union for the study of social insects, Copenhagen, Denmark
Trettin J, Haubner M, Buschinger A, Heinze J
- (2011) "Should I stay or should I go" - News from a high skew Insect society from central Spain. 4th Central European Workshop on Myrmecology, Cluj, Romania
Trettin J, Haubner M, Buschinger A, Heinze J
- (2011) Queen dominance and worker policing control reproduction in a threatened ant. BMC Ecology 11:21
Trettin J, Haubner M, Heinze J
