These are the supplementary materials associated with a project titled "Temporal differentiation in environmental niche modeling of Nearctic narrow-winged damselflies (Odonata: Coenagrionidae)". This work will be submitted as a manuscript to PeerJ. This work is supported by the NSF Grant Number EF-1400993.


General Information


Temporal differentiation in environmental niche modeling of Nearctic narrow-winged damselflies (Odonata: Coenagrionidae)


Project Dates

December 2016-May 2019


  • Amphiagrion abbreviatum
  • Argia moesta
  • Argia tibialis
  • Argia translata
  • Argia vivida
  • Chromagrion conditum
  • Enallagma civile
  • Enallagma hageni
  • Ischnura ramburii
  • Nehalennia irene


Narrow-winged damselflies (Odonata: Coenagrionidae) can be observed in a variety of habitats with relative ease, by both professional collectors and amateur odonatologists. Their high abundance and ease of recognition has resulted in a large amount of occurrence data, which can be used to establish species distribution through niche modeling. Often, distributional models aim to maximize the quantity of occurrence points and environmental variables to relate to the distribution, neglecting both the quality and overlap of these two datasets when generating the models. In order to examine the effects of temporal data and environmental variables influencing change in species distributions, we used digital occurrence data for twelve species of Coenagrionidae damselflies to generate niche models separated by time periods of specimen collection. Our study examines environmental niche models generated for four time periods for each of these coenagrionid species: Amphiagrion abbreivatum (Selys,1876), Enallagma civile (Hagen,1861), Chromagrion conditum (Hagen in Selys, 1876), Nehalennia gracilis Morse, 1895, Enallagma hageni (Walsh, 1863), Hesperagrion heterodoxum (Selys, 1868), Nehalennia irene (Hagen, 1861), Argia moesta (Hagen, 1861), Ischnura ramburii (Selys, 1850), Argia tibialis (Rambur, 1842), Argia translata Hagen in Selys, 1865, and Argia vivida Hagen in Selys, 1865. The best supported models in each analysis were generated with occurrences of specimens collected from the 1970s to 2000s, and we used occurrence data outside of this range, from the 1800s to 2017, to compare the consistency of model predictions based on specimens of different time periods. In this approach, combining traditional ecological niche modeling and analysis of the specimen records themselves, we have found that ranges for narrow-winged damselflies expand over time, with increase in distributional coverage and decrease in model strength without temporal overlap between occurrences and environmental variables.

File Descriptions

  • The folder S1. Raw occurrence data as CSVs from OdonataCentral used for generating occurrence file of each species for input into MaxEnt.
  • The folder S2 contains CSV files of the cleaned individual occurrences that were used to make the models of species distribution, separated by the following time periods: 1. pre-1970, 2. 1970-2000, 3. post-2000, 4. All available data.
  • The file S3 contains the Pearson Correlation Coefficients of the BIOCLIM climate variables, generated using SDMToolBox.
  • The file S4SupplementaryFigures contains supplementary figures for the other species referenced in the manuscript, generated from the raw MaxEnt output and edited in QGIS 3.4.4-Madeira.
  • The file S5 contains the AUC values and top variables in the models generated by MaxEnt.


The species occurrence coordinates were examined using ArcGIS. The occurrence and variable data were analyzed and the distribution maps were generated using MaxEnt software

To return the analysis in MaxEnt:

Input occurrence file for one species and/or partitioned species occurrence using the samples pathway. Input BIOCLIM files with all environmental variables that have already been analyzed for correlation in SDMToolbox and clipped to the region of North America.
Settings should be to create response curves, make pictures of predictions, do jackknife to measure variable importance, output format cloglog, output file, asc. Basic settings should be skip if output exists, random test percentage of 20.
The bias file of occurrences should be used to make a shapefile using the BIOLCLIM layers for the Nearctic. The shapefile (.asc) should be input as the bias file.
Output directory should go to a blank folder for that particular species. Once analyses are run, the folder will contain several files for each species and/or partitioned species.
These output files include an html file of the resultant model predicted by MaxEnt, including a list of settings and points/occurrence records used to generate the model. The CSV files in the output folder, show the occurrence pont averages, predictions, and omitted points.


Sandall, EL and Deans, AR, "Temporal differentiation in environmental niche modeling of Nearctic narrow-winged damselflies (Odonata: Coenagrionidae)", 2018. DOI: tbd.


Attribution 4.0 International (CC BY 4.0)

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