DOI: 10.5061/dryad.pg4f4qrzf
title: Common ant species dominate morphospace: unraveling the morphological diversity in the Brazilian Amazon Basin

description: Rare plant and vertebrate species have been documented to contribute
 disproportionately to the total morphological structure of species
 assemblages. These species often possess morphologically extreme traits
 and occupy the boundaries of morphological space. As rare species are at
 greater risk of extinction than more widely distributed species,
 human-induced disturbances can strongly affect ecosystem functions related
 to assemblage morphology. Here, we assess to what extent the distributions
 of ant morphological traits are supported by morphologically extreme
 species and how they are distributed among habitats in a global
 biodiversity hotspot, the Brazilian Amazon. We used a morphological
 database comprising 15 continuous morphological traits and 977
 expert-validated ant species distributed across the Brazilian Amazon. We
 produced species range estimates using species distribution models or
 alpha hulls (when few records were available). Next, we conducted a
 principal components analysis to combine traits into a space with reduced
 dimensionality (morphospace). Then, we identified morphologically extreme
 species in this space and quantified their contributions to morphological
 diversity across different habitat types in the Brazilian Amazon Basin. We
 identified 114 morphologically extreme ant species across the Amazon ant
 morphospace. These species also accounted for a large percentage of
 morphospace filling, exceeding 99% representation in the most disturbed
 habitats in the Amazon. Our results suggest that a few morphologically
 extreme species capture most of the variation in ant morphology and
 therefore, the spectrum of ecosystem functions performed by ants in the
 Brazilian Amazon Basin. Further, unlike for many other groups, these
 extreme morphologies were represented by the set of most common species.
 These results suggest greater functional redundancy and resilience in
 Brazilian Amazon ants, but more broadly, they contribute to our
 understanding of ecological processes that sustain ecosystem functions.
description: <strong>Occurrence and Morphological
 Datasets</strong> The primary occurrence database
 comprises historical and current ant records for the Brazilian Amazon
 (from 1817 to 2020). Data were obtained from the Global Ant Biodiversity
 Informatics project (GABI: Guénard et al. 2017; but also see database
 treatment in Andrade-Silva et al. 2022). We updated this dataset by
 incorporating new literature published in 2021 and 2022. Valid species
 names were based on the Online Catalog of the Ants of the World (AntCat:
 Bolton 2022, last checked in November 2022). We only considered nominal
 ant taxa (valid species and subspecies); informal taxa (morphospecies)
 were not included. We developed the morphological
 database from a set of 977 ant species (about 91% of the species recorded
 for the Brazilian Amazon Basin) and measured 15 continuous morphological
 traits, including HW = Head width; HL = Head length; CL = Clypeus length;
 ML = Mandible length; MW = Mandible width; FL = Hind femur length; SL =
 Scape length; WL = Weber’s length; ID = Inter-ocular distance; EL = Eyes
 length; PrW = Pronotum width; DEM = Distance of eye to mandible insertion;
 PeL = Petiole length; PeW = Petiole width; PeH = Petiole height.
 <strong>Vegetation Type Dataset</strong>
 We used a vegetation-type shapefile for the Brazilian Amazon
 provided by the Instituto Brasileiro de Geografia e Estatística (IBGE
 2012) to describe the regional morphological structure of ants from
 different habitats. The complex vegetation structure in the Amazon Basin
 is one of the main drivers of animal diversity, hosting varied
 microhabitats that enable interspecific coexistence (Laurance and
 Vasconcelos 2009, Fichaux et al. 2019). We defined nine main vegetation
 types in the Brazilian Amazon: (1) anthropic, (2) white sand forests
 (Campinaranas), (3) dense ombrophilous forests, (4) open ombrophilous
 forests, (5) pioneer vegetation (i.e., sand bars, mangroves), (6)
 savannah, (7) seasonal deciduous forest, (8) seasonal semideciduous
 forest, and (9) vegetational refuge (i.e., high-altitude fields, peat
 areas). We reclassified the IBGE vegetation shapefile by grouping
 vegetation classes within their immediately superior vegetation types. For
 example, we reclassified the classes "alluvial dense ombrophilous
 forest" and "lowland dense ombrophilous forest" into
 "dense ombrophilous forest". We reclassified vegetation types
 using shapefile dissolve operations in QGIS, version 2.18.2 (QGIS
 Development Team 2019).
description: # Common ant species dominate morphospace: unraveling the morphological
 diversity in the Brazilian Amazon Basin
 [https://doi.org/10.5061/dryad.pg4f4qrzf](https://doi.org/10.5061/dryad.pg4f4qrzf) Data on ant occurrence by vegetation types (Appendix table S1) and morphological measurements of ant species (Appendix table S2) were recorded in the Brazilian Amazon Basin. Morphological traits were delimited by the first four axes of a principal component analysis (PCA) and were used in the manuscript "Common ant species dominate morphospace: unraveling the morphological diversity in the Brazilian Amazon Basin". Morphological measurements taken for ant species included: HW = Head width; HL = Head length; CL = Clypeus length; ML = Mandible length; MW = Mandible width; FL = Hind femur length; SL = Scape length; WL = Weber’s length; ID = Inter-ocular distance; EL = Eyes length; PrW = Pronotum width; DEM = Distance of eye to mandible insertion; PeL = Petiole length; PeW = Petiole width; PeH = Petiole height. ## Description of the data and file structure **Table S1**: Occurrence database for ants by vegetation types in the Brazilian Amazon Basin. Ant records used in this study can be retrieved freely from [https://doi.org/10.5061/dryad.ht76hdrj8](https://doi.org/10.5061/dryad.ht76hdrj8), and metadata are available in Andrade-Silva et al. (2022). We used nine main vegetation types in the Brazilian Amazon, as provided by the Instituto Brasileiro de Geografia e Estatística (IBGE 2012): (1) anthropic, (2) white sand forests (Campinaranas), (3) dense ombrophilous forests, (4) open ombrophilous forests, (5) pioneer vegetation (i.e., sand bars, mangroves), (6) savannah, (7) seasonal deciduous forest, (8) seasonal semideciduous forest, and (9) vegetational refuge (i.e., high-altitude fields, peat areas). For more details on each vegetation type, please see 'Table 1' in Andrade-Silva et al. (2024). **Table S2**: Morphological database developed from a set of 977 ant species (about 91% of the species recorded for the Brazilian Amazon Basin) and 15 continuous morphological traits (see Table S1 in Andrade-Silva et al. 2024). We used the first four axes of an ordination (PCA) to reduce the number of input variables. Measurements were taken primarily through high-definition images available on Antweb or during visits to collections. Taxonomic literature was consulted for morphological measurements of ant species without available high-definition images from online databases. ### Reference cited Andrade-Silva, J., Baccaro, F. B., Prado, L. P., Guénard, B., Warren, D. L., Kass, J. M., Economo, E. P. and Silva, R. R. 2022. A large-scale assessment of ant diversity across the Brazilian Amazon Basin: integrating geographic, ecological and morphological drivers of sampling bias. Ecography, 9, e06295. [https://doi.org/10.1111/ecog.06295](https://doi.org/10.1111/ecog.06295). IBGE (Inst. Brasileiro de Geografia e Estatística). 2012. Manual técnico da vegetação brasileira: Sistema fitogeográfico, inventário das formações florestais e campestres, técnicas e manejo de coleções botânicas, procedimentos para mapeamentos. - IBGE. ### Citation: Andrade-Silva, J., Baccaro, F. B., Prado, L. P., Guenard, B., Kass, J. M., Warren, D. L., Economo, E. P. and Silva, R. R. 2024. Common ant species dominate morphospace: unraveling the morphological diversity in the Brazilian Amazon Basin. Ecography.