Conservation genetics and ecology of the endangered Black Bog Ant, Formica picea

Abstract

In this study I aimed to investigate the genetic and ecological factors that may Influence the distribution and conservation of the Black Bog Ant, Formica picea, within the UK, where it is classed as an endangered species. All main UK F. picea sites known at the start of this study (Cors Goch Llanllwch, Carmarthenshire Rhossili Down, West Glamorgan Hartland Moor, Dorset the New Forest, Hampshire) were investigated. The first study of its kind of a UK ant species, this investigation involved measuring micro-geographic ecological parameters and using both microsatellite and mitochondrial DNA markers for genetic analyses. High percentage cover of Bell Heather (Erica tetralix) and Deer Grass ( Trichophorum cespitosum) in the immediate vicinity of the nest and a low density of Heather (Calluna vulgaris) in the local area occupied by F. picea appear to contribute to favourable habitat. Water table level may be the most influential determinant of F. picea nest distribution, however, as an unoccupied area appearing favourable in terms of E. tetralix and T. cespitosum cover revealed significantly lower relative humidity and vegetation height in 2003. Colonies of all studied populations were highly polygynous, containing multiple reproducing queens per colony, and two populations revealed significant levels of inbreeding. Isolation by distance was detected in two populations, suggesting nest reproduction by budding and poor dispersal. All populations were genetically differentiated from one another, with the exception of the physically closest pair. Within Cors Goch Llanllwch a degree of social polymorphism was identified, with two sectors showing differing levels of polygyny and polydomy (multiple nests per colony). Aggression between non-nestmates was absent in this population, suggesting a largely unicolonial organisation. Despite relatively large population sizes conferred by polygyny, UK populations of F. picea are at risk due to ecological specificity, inbreeding and limited dispersal. Within this study I make suggestions for conservation management including detailed ecological analyses and colony relocation