Local coexistence of native and invasive ant species is associated with micro-spatial shifts in foraging activity

Abstract

Invasive species often displace native species by outcompeting them. Yet, some native species can persist even in heavily invaded areas. The mechanisms mediating this local coexistence are still unclear. Fine-scale microclimatic heterogeneity could promote the local coexistence of native and invasive animal competitors. We tested if native ant species could coexist with a recent ant invader, Tapinoma magnum, by shifting their foraging activity in time or space to different microclimatic conditions. We compared the foraging activity of native epigeic ant species among invaded and uninvaded sites. We collected ants at baits in green spaces on the north, east, south and west sides of buildings in the morning, at noon and in the afternoon to test if native species foraged under different microclimatic conditions in invaded sites. Invaded sites had lower ant species richness, diversity, and relative abundance. The native black garden ant Lasius nigerone of the most widespread Palearctic ant speciespersisted at high densities in invaded areas but foraged less on the east side of buildings and more on the west side.Microclimatic heterogeneity might promote native and invasive species coexistence by allowing some native species to shift their foraging behaviour to locally avoid or outcompete invasive competitors. Better understanding how fine-scale micro-environmental heterogeneity affects native species' persistence in invaded areas could help to predict and locally mitigate the negative impacts of biological invasions.

Colonization and coexistence of non‐native ants on a model Atlantic island

“…Our results did support the conclusions drawn by Balzani et al (2021) and Gippet et al (2022) on resource‐partitioning and climate heterogeneity, respectively. While we found considerable evidence that both processes promote non‐native ant coexistence on islands, we also found that not all studied species were impacted by each.…”

“…A third coexistence hypothesis is that environmental variation prevents competitive exclusion in diverse assemblages (Andersen, 2008;Hutchinson, 1961). Gippet et al (2022) found that native and invasive ants were able to coexist around buildings as a result of daily microclimatic variation.…”

“…A third coexistence hypothesis is that environmental variation prevents competitive exclusion in diverse assemblages (Andersen, 2008; Hutchinson, 1961). Gippet et al (2022) found that native and invasive ants were able to coexist around buildings as a result of daily microclimatic variation. In complex ecosystems, it is likely that diverse ant communities are maintained by a combination of each of the three mentioned coexistence mechanisms, although we can find no evidence that this has previously been tested.…”

Co‐occurrence of native white‐tailed deer and invasive wild pigs: Evidence for competition?

“…While interpreting co‐occurrence as a direct proxy for interactions without direct behavioral observations runs the risk of assuming negative responses reflect interspecific competition, there is some evidence from this work that deer might experience interference competition from wild pigs at a fine scale. However, we found no evidence that wild pigs broadly displace deer from using an area, and fine‐scale spatial adjustments may be the mechanism enabling long‐term co‐existence of deer and wild pigs, as observed in other native species (e.g., blue tit, Cyanistes caeruleus , and great tit, Parus major , Peck et al, 2014; green anole lizard, Anolis carolinensis , Bush et al, 2021; black garden ant, Lasius niger , Gippet et al, 2021; wild turkeys, Meleagris gallopavo , Walters & Osborne, 2022).…”