Predicting community structure of ground-foraging ant assemblages with Markov models of behavioral dominance.
Although interference competition is a conspicuous component of many animal communities, it is still uncertain whether the competitive ability of a species determines its relative abundance and patterns of association with other species. We used replicated arena tests to quantify behavioral dominance of eight common species of co-occurring ground-foraging ants in the Siskiyou Mountains of southern Oregon. We found that behavior recorded in laboratory assays was an accurate representation of a colony's ability to monopolize resources in the field. We used interaction frequencies from the behavioral tests to estimate transition probabilities in a simple Markov chain model to predict patterns of relative abundance in a metacommunity that is dominated by behavioral interactions. We also tested whether behavioral interactions between each pair of species could be used to predict patterns of species co-occurrence. We found that the Markov model did not accurately predict patterns of observed relative abundance on either the local or the regional scale. However, we did detect a significant negative correlation at the local scale in which behaviorally dominant species occupied relatively few baits. Pairwise behavioral data also did not predict species co-occurrence in any site. Although interference competition is a conspicuous process in ant communities, our results suggest that it may not contribute much to patterns of relative abundance and species co-occurrence in the system studied here. However, the negative correlation between behavioral dominance and bait occupancy at the local scale suggests that competition-colonization trade-offs may be important in resource acquisition and persistence of behaviorally subordinate species.
Wittman
Sarah E
SE
Department of Biology, University of Vermont, Burlington, VT 05405, USA. S.Wittman@latrobe.edu.au
Gotelli
Nicholas J
NJ
D000818:Animals; D001000:Ants; D002140:California; D003163:Competitive Behavior; D017753:Ecosystem; D008390:Markov Chains; D009922:Oregon; D012930:Social Dominance