The impact of ants and vertebrate predators on arthropods and plants: a meta-analysis

We report a meta-analysis of 486 experiments gathered from 157 publications reporting the effect of insectivorous vertebrates (birds and bats) and ants on richness and abundances of all arthropods; predatory (spiders, ants, others) and herbivorous (chewers and others) arthropods; and on plant damage. We conducted an extensive survey of the literature on manipulative field studies where (i) birds, bats, lizards, and ants were experimentally excluded individually or in combination with either field cages or netting, (ii) matched with appropriate open-access controls, and (iii) the effects of their removal were measured on terrestrial plants and/or naturally occurring arthropod populations or communities. In Web of Science (All collections) and Google Scholar, we searched the terms “bird AND exclosure”, “bat AND exclosure”, “ant AND exclosure” and “lizard AND exclosure”. In addition, we searched for the term “exclusion” instead of “exclosure”, in the same combinations. Our initial search found 546, 18, 19 and 4 studies, respectively. Subsequently, we removed all duplicates, and we ended up with 382 potentially suitable studies. We also identified several meta-analyses such as (Mooney et al. 2010) who reviewed 64 studies and (Maas 2019) who reviewed 30 to identify any studies we had missed. We identified a further 153 suitable studies and topped up the dataset with 4 unpublished datasets which we obtained by contacting authors directly.