Effects of Invasive European Fire Ants (Myrmica rubra) on Herring Gull (Larus argentatus) Reproduction

Abstract

Various invasive ant species have negatively affected reproductive success in birds by disrupting nest site selection, incubation patterns, food supply, and by direct predation on nestlings. Impacts can be particularly severe when non-native ants colonize seabird nesting islands where thousands of birds may nest in high densities on the ground or in burrows or crevices. Here we report on the first documented effects of Myrmica rubra, the European fire ant, on the reproduction of birds in its non-native range. We documented herring gulls (Larus argentatus) on Appledore Island, Maine, engaging in more erratic incubation behaviors at nests infested by the ants. Newly-hatched chicks in some nests were swarmed by ants, leading to rapid chick death. Due to high overall rates of chick mortality, survival probabilities did not vary between nests with and without ant activity, however chick growth rates were slower at nests with ants than at ant-free nests. Ant infestation likely leads to longer-term fitness consequences because slower growth rates early in life may ultimately lead to lower post-fledging survival probabilities.

Thermal ecosystem engineering by songbirds promotes a symbiotic relationship with ants

“…Ants, like other predators, such as spiders or mites, might provide nest sanitation for birds by www.nature.com/scientificreports/ reducing numbers of ectoparasites 22,24,29,50,51 . Although ants may also occasionally kill nestlings 29,52,53 , no cases of ant aggression toward the hosts were observed during this study. Even when ants were disturbed by observers, and defensive workers emerged from the warbler nests, the nestlings inside remained unharmed and adult birds showed no sign of distress.…”

Cohabitation of tree holes by ants and breeding birds in a temperate deciduous forest

“…In a nest box experiment in Northern Sweden, Haemig (1999) found that tits (Paridae) were attracted to trees used by foraging Formica aquilonia, but only at places with the high predation risk. As ants can constitute threats to birds' nests (Haemig 1999;DeFisher & Bonter 2013), breeding next to the ant colonies could also have negative consequences to birds.…”

Prevalence and consequences of ants and other arthropods in active nests of Midwestern birds

“…Some ants also occasionally associate with bird nests. Workers of many ant species have been found in the nests of birds (Hicks 1959;Blem and Blem 1994;Di Iorio and Turienzo 2009) and can even kill nestlings (reviewed in Suarez et al 2005;DeFisher and Bonter 2013). A few species have been documented occupying bird nests, wherein ants will move all or a significant portion of their colony into the nest material (Smith 1928;Fessl et al 2006;Lambrechts et al 2008;Gouveia et al 2012;Lambrechts and Schatz 2014;Mitrus et al 2015;Maziarz et al 2018).…”