. Author manuscript; available in PMC: 2021 May 26.

Published in final edited form as: Exp Appl Acarol. 2020 Jan 21;80(2):227–245. doi: 10.1007/s10493-019-00460-7

Table 1.

Three sets of environmental variables used for three Amblyomma americanum MaxEnt calibration models and the four steps of the jackknife procedure used to select the environmental variables in each set

Jackknife step/environmental variable set	Bioclimatic variables used in Maxent calibration model
Step 1	All Bioclim variables^a
Step 2/Set 1	BIO_{1 =} Annual Mean Temperature BIO₂ = Mean Diurnal Range (Mean of monthly (max temp—min temp)) BIO₅ = Max Temperature of Warmest Month BIO₆ = Min Temperature of Coldest Month BIO₁₁ = Mean Temperature of Coldest Quarter BIO₁₂ = Annual Precipitation BIO₁₃ = Precipitation of Wettest Month BIO₁₄ = Precipitation of Driest Month BIO₁₅ = Precipitation Seasonality (Coefficient of Variation) BIO₁₆ = Precipitation of Wettest Quarter BIO₁₇ = Precipitation of Driest Quarter
Step 3/Set 2	BIO₁ = Annual Mean Temperature BIO₅ = Max Temperature of Warmest Month BIO₁₁ = Mean Temperature of Coldest Quarter BIO₁₂ = Annual Precipitation BIO₁₄ = Precipitation of Driest Month BIO₁₅ = Precipitation Seasonality (Coefficient of Variation) BIO₁₇ = Precipitation of Driest Quarter
Step 4/Set 3	BIO₁ = Annual Mean Temperature BIO₁₂ = Annual Precipitation BIO₁₅ = Precipitation Seasonality (Coefficient of Variation) BIO₁₇ = Precipitation of Driest Quarter

The following BioClim bioclimatic variables, Mean Temperature of Wettest Quarter (BIO₈), Mean Temperature of Driest Quarter (BIO₉), Precipitation of Warmest Quarter (BIO₁₈), Precipitation of Driest Quarter (BIO₁₉) were a priori excluded from the WorldClim archive because these layers have been shown to have spatial artefacts that could affect niche modelling (Escobar et al. 2014)