02301nas a2200157 4500008004100000245009800041210006900139260002100208300001200229490000800241520172300249100001501972700001601987700001602003856012402019 2009 eng d00aInvasive ants compete with and modify the trophic ecology of hermit crabs on tropical islands0 aInvasive ants compete with and modify the trophic ecology of her cMay 2009, Publis a187-1940 v1603 a*[Here, we demonstrate how the trophic ecology of the remote atoll nation of Tokelau is changing due to competition between the invasive ant, Anoplolepis gracilipes, & native terrestrial hermit crabs, Coenobita spp., for carrion. A significant negative correlation was observed between A. gracilipes & hermit crab abundance. On islands with A. gracilipes, crabs were generally restricted to the periphery of invaded islands. Very few hermit crabs were found in central areas of these islands, where A. gracilipes abundances were highest. Ant exclusion experiments demonstrated that changes in the abundance & distribution of hermit crabs on Tokelau are a result of competition. The ants did not kill the hermit crabs. Rather, when highly abundant, A. gracilipes attacked crabs by spraying acid, driving crabs away from carrion resources. Analysis of naturally occurring N and C isotopes suggests that the ants are effectively lowering the trophic level of crabs. According to delta-15N values, hermit crabs have a relatively high trophic level on islands where A. gracilipes have not invaded. In contrast, where these ants have invaded, we observed a significant decrease in delta-15 N for all crab species. This result concurs with our experiment in suggesting long-term exclusion from carrion resources, driving co-occurring crabs towards a more herbivorous diet. Changes in hermit crab abundance or distribution may have major ramifications for the stability of plant communities. Because A. gracilipes have invaded many tropical islands where the predominant scavengers are hermit crabs, we consider that their competitive effects are likely to be more prominent in structuring communities than predation.]1 aMcNatty, A1 aAbbott, K L1 aLester, P J uhttps://antkey.myspecies.info/en/content/invasive-ants-compete-and-modify-trophic-ecology-hermit-crabs-tropical-islands00847nas a2200109 4500008004100000245018100041210006900222260008500291520021400376100001600590856013100606 2004 eng d00aAlien ant invasion on Christmas Island, Indian Ocean: the role of ant-scale associations in the dynamics of supercolonies of the yellow crazy ant, Anoplolepis gracilipes0 aAlien ant invasion on Christmas Island Indian Ocean the role of  bPh.D. Thesis, Bioloical Sciences, Monash University, Melbourne, Australia, 227 p3 a

*Cited from: Abbott, K.L., 2005, Supercolonies of the invasive yellow crazy ant, Anoplolepis gracilipes, on an oceanic island: Forager activity patterns, density and biomass, Insect. Soc. 52: 266-273.

1 aAbbott, K L uhttps://antkey.myspecies.info/en/content/alien-ant-invasion-christmas-island-indian-ocean-role-ant-scale-associations-dynamics01130nas a2200133 4500008004100000245015200041210006900193260001600262300001200278490000700290520055000297100001600847856013300863 2005 eng d00aSupercolonies of the invasive yellow crazy ant, Anoplolepis gracilipes, on an oceanic island: Forager activity patterns, density and biomass0 aSupercolonies of the invasive yellow crazy ant iAnoplolepis grac cAugust 2005 a266-2730 v523 a*[Densities of up to 2254 foraging ants per m/2 and a biomass of 1.85 g per m/2 were recorded and nest densities reached 10.5 nest entrances per m/2. These population cand kill red endemic land crabs. Ant activity was estimated by the number of ants crossing a 10 cm X 10 cm laminated white card on the ground in 30 seconds. Biomass estimated by weighing and counting vacuum-collected unfed workers with undistended abdomens. Biomass estimates did not account for brood, queens or alates. Nest entrances were counted in 3 m X 3m quadrants.]1 aAbbott, K L uhttps://antkey.myspecies.info/en/content/supercolonies-invasive-yellow-crazy-ant-ianoplolepis-gracilipesi-oceanic-island-forager01913nas a2200133 4500008004100000245013700041210006900178260001700247300001200264490000700276520134300283100001601626856013701642 2006 eng d00aSpatial dynamics of supercolonies of the invasive yellow crazy ant, Anoplolepis gracilipes, on Christmas Island, Indian Ocean0 aSpatial dynamics of supercolonies of the invasive yellow crazy a cJanuary 2006 a101-1100 v123 a

*[This study examines the spatial dynamics of high-density supercolonies of the invasive yellow crazy ant, Anoplolepis gracilipes, on Christmas Island, Indian Ocean, and the associated impacts at their boundaries. Since the early 1990's, A. gracilipes supercolonies have occupied over 30% of the 10,000-ha of rainforest on Christmas Island. Thirty-four discrete high-density supercolonies formed between 1989 & 2003, ranging in size across nearly 3-orders of magnitude from 0.9 to 787-ha. Supercolonies boundaries are diffuse, & ants were observed in low densities in some cases up to 200-m from the main high-density supercolony. The 13 boundaries examined were all dynamic over a 10-20 observation month period, 9 boundaries expanded, & the maximum rate of spread was 0.5-m day-1. Across boundary transition zones, between high-density supercolonies & intact rainforest, A. gracilipes reduced other ant species richness, occupied red crab burrows, & killed resident red crabs, which was the trigger for 'invasional meltdown' on Christmas Island. The highly variable & unpredictable nature of A. gracilipes boundaries poses a challenge for incorporation into a predictive framework, as well as for their management. Gives good evidence that mating flights do occur as well as colony budding.]

1 aAbbott, K L uhttps://antkey.myspecies.info/en/content/spatial-dynamics-supercolonies-invasive-yellow-crazy-ant-ianoplolepis-gracilipesi-christmas02236nas a2200169 4500008004100000245015200041210006900193260001400262300001200276490000600288520157000294100001601864700001901880700001701899700001601916856013401932 2007 eng d00aBehaviourally and genetically distinct populations of an invasive ant provide insight into invasion history and impacts on a tropical ant community0 aBehaviourally and genetically distinct populations of an invasiv cJune 2007 a453-4630 v93 aPopulations of invasive species often exhibit a high degree of spatial and temporal variability in abundance and hence their effects on resident communities. Here, we examine behavioral, genetic and environmental factors that influence variation in populations of the yellow crazy ant, Anoplolepis gracilipes, on the remote Nukunonu Atoll of Tokelau, Pacific Ocean. Behavioral assays revealed high levels of aggression between two groups of yellow crazy ants from different islands, and genetic analysis confirmed the presence of two distinct populations with unique mitochondrial (mt)DNA haplotypes, designated A and D. The two populations likely resulted from two separate invasion events. The populations exhibited significant differences in abundance of A. gracilipes, with a mean sevenfold difference in relative abundance between the two main haplotypes. The higher density haplotype D population coexisted with 50% fewer other ant species and altered ant community composition. Vegetation composition was also significantly different on islands harbouring the two populations. The results suggest genetic differences could play a role in the spatial and temporal variation in the effect of the yellow crazy ant on a small oceanic atoll. We could not differentiate between genetic effects and effects of vegetation. However, our results indicate that spatial variability in behavior and impacts within populations of invasive species could be in part due to genetic differences, and play a substantial role in influencing the outcome of biological invasions.1 aAbbott, K L1 aGreaves, S N J1 aRitchie, P A1 aLester, P J uhttps://antkey.myspecies.info/en/content/behaviourally-and-genetically-distinct-populations-invasive-ant-provide-insight-invasion01649nas a2200145 4500008004100000245007500041210006900116260000900185300001400194490000800208520115400216100001601370700001501386856010201401 2007 eng d00aCollapse of an ant-scale mutualism in a rainforest on Christmas Island0 aCollapse of an antscale mutualism in a rainforest on Christmas I cJuly a1238-12460 v1163 a

Positive interactions play a widespread role in facilitating biological invasions. Here we use a landscape-scale ant exclusion experiment to show that widespread invasion of tropical rainforest by honeydew-producing scale insects on Christmas Island (Indian Ocean) has been facilitated by positive interactions with the invasive ant Anoplolepis gracilipes. Toxic bait was used to exclude A. gracilipes from large (9-35 ha) forest patches. Within 11 weeks, ant activity on the ground and on trunks had been reduced by 98-100%, while activity on control plots remained unchanged. The exclusion of ants caused a 100% decline in the density of scale insects in the canopies of three rainforest trees in 12 months (Inocarpus fagifer, Syzygium nervosum and Barringtonia racemosa), but on B. racemosa densities of scale insects also declined in control plots, resulting in no effect of ant exclusion on this species. This study demonstrates the role of positive interactions in facilitating biological invasions, and supports recent models calling for greater recognition of the role of positive interactions in structuring ecological communities.

1 aAbbott, K L1 aGreen, P T uhttps://antkey.myspecies.info/en/content/collapse-ant-scale-mutualism-rainforest-christmas-island