Lethal sibling rivalry for nest inheritance among virgin ant queens

Abstract

Fights among conspecific animals are normally restricted to ritualized interactions. They may escalate to serious injury and death when the contested resource has a very high value and the chances of finding alternative resources later in life are low. This appears to be the case in young queens of the ant Cardiocondyla ''latifrons'', a species that builds its nests in rather stable rock crevices. Young queens in small colonies without a mature queen fought violently for inheritance of the nest site and its workers. Queen aggression and subsequent attacks by workers killed about 50% of the young queens in our experimental nests. Queen killing differs qualitatively from previously reported dominance interactions among prospective female reproductives in other ants, which are mostly ritualized and allow losers to pursue alternative ways of increasing their direct or indirect fitness. Our observations add a novel case of siblicide to the previously reported lethal aggression among nestling birds, parasitoid larvae, and honey bee queens. They corroborate the hypothesis that relatedness does not play a significant role in local competition for highly limited resources.

Social influence on age and reproduction: reduced lifespan and fecundity in multi‐queen ant colonies

“…For example, fighting among queens for reproductive rights or resources might result in a lower lifespan and fecundity (e.g. Heinze & Weber, 2011), or workers might care only for queens with a high egg‐laying rate. Furthermore, queens themselves or their workers might adjust queen lifespan to changed life history and reproductive tactics.…”

Massacre of the innocents in Cardiocondyla thoracica: Manipulation by adult ant males incites workers to kill their immature rivals

“…Cardiocondyla thoracica forms the well‐supported sister taxon of a clade comprising C. pirata (Seifert & Frohschammer ) and several undescribed taxa of the Southeast Asian C. “ argentea ” group (Oettler et al . ; Heinze & Weber ). The cluster of C. thoracica and C .…”

“…To determine whether queens of C. thoracica form dominance hierarchies by aggressive interactions as they do in related species (Yamauchi et al . ; Heinze & Weber ) we individually marked 12 queens from three colonies (AUS 23, AUS23a and AUS 20) with 30 µm copper wire (Electrisola, Eckenhagen, Germany) between alitrunk, petiole, postpetiole and gaster. Observations were done at room temperature under a binocular microscope for 10 h per colony with individual observation sessions of 60–120 min.…”

“…In the Cardiocondyla clade with males with sickle‐shaped mandibles it ranges from mutual tolerance in C. obscurior (polygyny) to dominance hierarchies and fighting in C. “ latifrons ” and C. “ argyrotricha ” (provisional names of recognized morphospecies currently described by B. Seifert) (Yamauchi et al . ; Heinze & Weber ; Schmidt et al . ).…”

Life-history evolution in ants: the case ofCardiocondyla

“…[41]). Two lineages-a few species of the Southeast Asian Cardiocondyla 'argentea' group ( preliminary name for a taxon currently being described by B. Seifert) and the large clade of Palaearctic Cardiocondyla-have convergently evolved singlequeening (monogyny) [10,[43][44][45]. Nevertheless, both lineages have retained intranidal mating, which results in the temporary presence of multiple potential reproductives in a single nest.…”