Environmental niche unfilling but limited options for range expansion by active dispersion in an alien cavity-nesting wasp

Table 1 The 20 environmental (climate and altitude) variables retrieved from Worldclim and used in the study to build the environmental niche of I. mexicana

Worldclim code	Definition	Factor 1	Factor 2	Factor 3
BIO1	Annual mean temperature	0.935	0.325	− 0.102
BIO2	Mean diurnal range [mean of monthly (max temp − min temp)]	0.327	0.724	0.093
BIO3	Isothermality (BIO2/BIO7) (* 100)	0.911	0.047	0.132
BIO4	Temperature seasonality (standard deviation * 100)	− 0.900	0.019	− 0.138
BIO5	Max temperature of warmest month	0.734	0.561	− 0.249
BIO6	Min temperature of coldest month	0.962	0.161	− 0.054
BIO7	Temperature annual range (BIO5–BIO6)	− 0.843	0.187	− 0.108
BIO8	Mean temperature of wettest quarter	0.732	0.399	− 0.151
BIO9	Mean temperature of driest quarter	0.893	0.248	− 0.093
BIO10	Mean temperature of warmest quarter	0.797	0.490	− 0.251
BIO11	Mean temperature of coldest quarter	0.959	0.217	− 0.028
BIO12	Annual precipitation	0.669	− 0.699	0.096
BIO13	Precipitation of wettest month	0.701	− 0.464	0.326
BIO14	Precipitation of driest month	0.300	− 0.805	− 0.290
BIO15	Precipitation seasonality (coefficient of variation)	0.257	0.606	0.505
BIO16	Precipitation of wettest quarter	0.700	− 0.501	0.307
BIO17	Precipitation of driest quarter	0.334	− 0.813	− 0.277
BIO18	Precipitation of warmest quarter	0.469	− 0.598	0.214
BIO19	Precipitation of coldest quarter	0.487	− 0.630	− 0.133
ALTITUDE	–	− 0.146	− 0.009	0.737

The R² of the correlations between the 20 variables and first three factors of the PCA obtained from these variables are shown (values in italic represent the variables most likely to explain the PCA factors)

ISSN: 1472-6785