Ant brightness and size influence the seasonal vegetation use by ground-dwelling ants (Hymenoptera: Formicidae) in an Amazonia-Cerrado transition zone
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Wiley
Abstract
• Several factors influence species distribution within communities, with ecological filters playing a major role by shaping morphological, physiological and behavioural adaptations. Seasonal changes in environmental conditions—light incidence, temperature and humidity—can favour species capable of foraging under varying conditions or in different strata.
• Ants are excellent models for studying how ecological filters structure communities throughout the year, as they exhibit traits that enable them to occupy a wide range of microhabitats. Two such traits that may reflect responses to environmental filters are body size and brightness. In this study, we investigated how ant distribution varies between soil and lower vegetation across two seasons, and how these patterns relate to ant morphology in an ecotonal area between the Amazon and Cerrado biomes.
• Ants were sampled using pitfall traps placed on the ground and in the lower vegetation. We measured the size and brightness of representative individuals from each species. A total of 2659 occurrences were recorded, representing 237 species, 53 genera and 8 subfamilies. Species richness was higher during the dry season, especially in the soil. Species turnover was the main component of beta diversity, although this pattern varied with season. During the rainy season, many ground-dwelling ants shifted to the vegetation, increasing the nestedness component in cross-strata comparisons. Larger ants were more frequent in vegetation, while smaller ants predominated in the soil. Darker individuals were more common in vegetation during the dry season; however, this seasonal migration of ground ants to the vegetation led to a lighter-coloured ant community on average during the rainy season.
• These findings show that ant community composition in the soil and lower vegetation is not stable year-round. Seasonal climatic conditions influence foraging activity and species presence, highlighting the importance of seasonal dynamics and vertical stratification in shaping community structure.
Description
DATA AVAILABILITY STATEMENT : The data that support the findings of this study are openly available in Dryad at https://doi.org/10.5061/dryad.r2280gbp8.
SUPPLEMENTARY MATERIAL
TABLE S1. Data of filtered environmental variables from September 2023 and February 2024 available at the National Institute of Meteorology (INMET) of the meteorological station in São José do Xingu-MT, Brazil. Available at: https://portal.inmet.gov.br/ [Accessed 25th March 2024].
TABLE S2. Records of ant species (Hymenoptera: Formicidae) collected at Xingu State Park across two seasons (dry and rainy) and two strata (ground and low vegetation). The numbers for each species represent their frequency (number of sampling points where they were present) in each treatment.
FIGURE S1. Raw number of species (on the left) and Hills diversity (q = 1) (on the right) of ants collected per plot in Xingu State Park (PEX) in the Dry and Rainy seasons in the terrestrial and vegetation strata. The number of species is higher on the soil (Negative Binomial GLMM χ21,19 = 158.16, p < 0.001) but did not differ between seasons (GLMM χ21,19 = 0.7, p = 0.4) and there is no interaction between strata and seasons (GLMM χ21,19 = 2.15, p = 0.14). We employed here hill number to attenuate the effect of differences in the number of occurrences (abundance) of ants, however the results are virtually the same of the found on real number of species: The is Hills diversity of ants per plot was higher on ground strata (GLMM χ21,19 = 150.16, p < 0.001), but, we did not observe any significant differences in the richness of vegetation ants between seasons (χ21,19 = 1.7, p = 0.19) or interaction (χ21,19 = 2.78, p = 0.10). The different letters above the boxes indicate statistically significant differences (p < 0.05).
FIGURE S2. Rarefaction curves (solid lines) with extrapolation to 1034 individuals (dashed lines), representing the maximum sample size observed (Soil/Dry season). The overall community pattern reinforces the differences in species richness per plot observed in Figure S1a,b, showing consistent differences between strata. However, the rarefaction curves reveal an emergent pattern not detected at the plot level. While vegetation strata exhibit stable species richness across seasons (Vegetation/Dry ≈ Vegetation/Rainy), the soil strata show higher overall richness in the dry season than in the rainy season. This difference is observable in the median number of species in the raw data (Figure S1a), but it is not significant, as there is natural variance among plots.
Keywords
Adaptations, Ants, Colour, Morphology, Seasonality, Stratification
Sustainable Development Goals
SDG-15: Life on land
Citation
Bochenski, W.S., Vicente, R.E., Bishop, T.R. & Izzo, T.J. (2025) Ant brightness and size influence the seasonal vegetation use by ground-dwelling ants (Hymenoptera: Formicidae) in an Amazonia-Cerrado transition zone. Ecological Entomology, 50(6), 1082–1095. Available from: https://doi.org/10.1111/een.70000.