Ethiopia’s church forests are some of the last remaining patches of forest in the highlands of Ethiopia. These forests surround Orthodox Christian churches, some dating back to the 4th century. The stewards of these churches are priests and they believe that the forests are sacred. When looking from above the church forests appear as little islands in an otherwise rugged landscape dominated by farmland. An ongoing conservation effort led by Dr. Meg Lowman (“Canopy Meg”) is trying to combat the continuous decline of these forests (see Dr. Lowman’s website for more details). In January 2012, I was part of a team to study these church forests. The goal was to survey the biodiversity and my job (along with Dr. Mark Moffett) was to look at ants (- no surprise there).
What we found was intriguing. There was a single ant species that dominated entire forests, in fact, it was hard to find any other ant species around. Lepisiota canescens exhibited behavioral characteristics similar to invasive species like Argentine ants or fire ants. We conducted aggression assays to determine if these ants, like Argentine ants (Linepithema humile) and fire ants (Solenopsis invicta), might also form supercolonies. And indeed, our results support this hypothesis – we found stretches of up to 38 km with no aggression between workers. In addition, we analyzed mitochondrial genetic diversity to investigate if these ants, like Argentine ants in most places, are indeed invasive. Our results show the genetic signature of a native species. In fact, they show significant genetic diversity within supercolonies.
The paper describing our results has been published in the journal Insectes Sociaux:
Sorger D.M., W. Booth, A. Wassie Eshete, M. Lowman & M.W. Moffett (2016) Outnumbered: A new dominant ant species with genetically diverse supercolonies in Ethiopia. Insectes Sociaux. DOI 10.1007/s00040-016-0524-9 PDF