Ants pick up the slack when other scavengers are absent from rainforest ecosystems, despite already doing the lion’s share of such work.
Ants help to keep rainforest floors clear by taking seeds, other plant matter and even decaying carcasses back to their nests, which, in turn, creates hotspots of forest diversity. Louise Ashton at the Natural History Museum in London and her team quantified, for the first time, how much of the clean-up ants actually take on, by manipulating food availability and forager numbers in the rainforest in Sabah, Malaysia.
In a normal foraging community, ants took on 52% of the workload, leaving the rest for other insects and small vertebrates. When scavenging vertebrates were removed, ants compensated for the loss of help and took home 61% or more of the food resources. Other invertebrates did not pick up the slack in any significant way. The authors say the finding shows the importance of preventing ant decline in areas threatened by human activities.